summaryrefslogtreecommitdiff
path: root/kernel/bpf
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2024-01-11 10:07:29 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2024-01-11 10:07:29 -0800
commit3e7aeb78ab01c2c2f0e1f784e5ddec88fcd3d106 (patch)
treebdbfd45f8d8e967b06ed2d9cb92f67f686d02659 /kernel/bpf
parentde927f6c0b07d9e698416c5b287c521b07694cac (diff)
parenta7fe0881d9b78d402bbd9067dd4503a57c57a1d9 (diff)
Merge tag 'net-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Paolo Abeni: "The most interesting thing is probably the networking structs reorganization and a significant amount of changes is around self-tests. Core & protocols: - Analyze and reorganize core networking structs (socks, netdev, netns, mibs) to optimize cacheline consumption and set up build time warnings to safeguard against future header changes This improves TCP performances with many concurrent connections up to 40% - Add page-pool netlink-based introspection, exposing the memory usage and recycling stats. This helps indentify bad PP users and possible leaks - Refine TCP/DCCP source port selection to no longer favor even source port at connect() time when IP_LOCAL_PORT_RANGE is set. This lowers the time taken by connect() for hosts having many active connections to the same destination - Refactor the TCP bind conflict code, shrinking related socket structs - Refactor TCP SYN-Cookie handling, as a preparation step to allow arbitrary SYN-Cookie processing via eBPF - Tune optmem_max for 0-copy usage, increasing the default value to 128KB and namespecifying it - Allow coalescing for cloned skbs coming from page pools, improving RX performances with some common configurations - Reduce extension header parsing overhead at GRO time - Add bridge MDB bulk deletion support, allowing user-space to request the deletion of matching entries - Reorder nftables struct members, to keep data accessed by the datapath first - Introduce TC block ports tracking and use. This allows supporting multicast-like behavior at the TC layer - Remove UAPI support for retired TC qdiscs (dsmark, CBQ and ATM) and classifiers (RSVP and tcindex) - More data-race annotations - Extend the diag interface to dump TCP bound-only sockets - Conditional notification of events for TC qdisc class and actions - Support for WPAN dynamic associations with nearby devices, to form a sub-network using a specific PAN ID - Implement SMCv2.1 virtual ISM device support - Add support for Batman-avd mulicast packet type BPF: - Tons of verifier improvements: - BPF register bounds logic and range support along with a large test suite - log improvements - complete precision tracking support for register spills - track aligned STACK_ZERO cases as imprecise spilled registers. This improves the verifier "instructions processed" metric from single digit to 50-60% for some programs - support for user's global BPF subprogram arguments with few commonly requested annotations for a better developer experience - support tracking of BPF_JNE which helps cases when the compiler transforms (unsigned) "a > 0" into "if a == 0 goto xxx" and the like - several fixes - Add initial TX metadata implementation for AF_XDP with support in mlx5 and stmmac drivers. Two types of offloads are supported right now, that is, TX timestamp and TX checksum offload - Fix kCFI bugs in BPF all forms of indirect calls from BPF into kernel and from kernel into BPF work with CFI enabled. This allows BPF to work with CONFIG_FINEIBT=y - Change BPF verifier logic to validate global subprograms lazily instead of unconditionally before the main program, so they can be guarded using BPF CO-RE techniques - Support uid/gid options when mounting bpffs - Add a new kfunc which acquires the associated cgroup of a task within a specific cgroup v1 hierarchy where the latter is identified by its id - Extend verifier to allow bpf_refcount_acquire() of a map value field obtained via direct load which is a use-case needed in sched_ext - Add BPF link_info support for uprobe multi link along with bpftool integration for the latter - Support for VLAN tag in XDP hints - Remove deprecated bpfilter kernel leftovers given the project is developed in user-space (https://github.com/facebook/bpfilter) Misc: - Support for parellel TC self-tests execution - Increase MPTCP self-tests coverage - Updated the bridge documentation, including several so-far undocumented features - Convert all the net self-tests to run in unique netns, to avoid random failures due to conflict and allow concurrent runs - Add TCP-AO self-tests - Add kunit tests for both cfg80211 and mac80211 - Autogenerate Netlink families documentation from YAML spec - Add yml-gen support for fixed headers and recursive nests, the tool can now generate user-space code for all genetlink families for which we have specs - A bunch of additional module descriptions fixes - Catch incorrect freeing of pages belonging to a page pool Driver API: - Rust abstractions for network PHY drivers; do not cover yet the full C API, but already allow implementing functional PHY drivers in rust - Introduce queue and NAPI support in the netdev Netlink interface, allowing complete access to the device <> NAPIs <> queues relationship - Introduce notifications filtering for devlink to allow control application scale to thousands of instances - Improve PHY validation, requesting rate matching information for each ethtool link mode supported by both the PHY and host - Add support for ethtool symmetric-xor RSS hash - ACPI based Wifi band RFI (WBRF) mitigation feature for the AMD platform - Expose pin fractional frequency offset value over new DPLL generic netlink attribute - Convert older drivers to platform remove callback returning void - Add support for PHY package MMD read/write New hardware / drivers: - Ethernet: - Octeon CN10K devices - Broadcom 5760X P7 - Qualcomm SM8550 SoC - Texas Instrument DP83TG720S PHY - Bluetooth: - IMC Networks Bluetooth radio Removed: - WiFi: - libertas 16-bit PCMCIA support - Atmel at76c50x drivers - HostAP ISA/PCMCIA style 802.11b driver - zd1201 802.11b USB dongles - Orinoco ISA/PCMCIA 802.11b driver - Aviator/Raytheon driver - Planet WL3501 driver - RNDIS USB 802.11b driver Driver updates: - Ethernet high-speed NICs: - Intel (100G, ice, idpf): - allow one by one port representors creation and removal - add temperature and clock information reporting - add get/set for ethtool's header split ringparam - add again FW logging - adds support switchdev hardware packet mirroring - iavf: implement symmetric-xor RSS hash - igc: add support for concurrent physical and free-running timers - i40e: increase the allowable descriptors - nVidia/Mellanox: - Preparation for Socket-Direct multi-dev netdev. That will allow in future releases combining multiple PFs devices attached to different NUMA nodes under the same netdev - Broadcom (bnxt): - TX completion handling improvements - add basic ntuple filter support - reduce MSIX vectors usage for MQPRIO offload - add VXLAN support, USO offload and TX coalesce completion for P7 - Marvell Octeon EP: - xmit-more support - add PF-VF mailbox support and use it for FW notifications for VFs - Wangxun (ngbe/txgbe): - implement ethtool functions to operate pause param, ring param, coalesce channel number and msglevel - Netronome/Corigine (nfp): - add flow-steering support - support UDP segmentation offload - Ethernet NICs embedded, slower, virtual: - Xilinx AXI: remove duplicate DMA code adopting the dma engine driver - stmmac: add support for HW-accelerated VLAN stripping - TI AM654x sw: add mqprio, frame preemption & coalescing - gve: add support for non-4k page sizes. - virtio-net: support dynamic coalescing moderation - nVidia/Mellanox Ethernet datacenter switches: - allow firmware upgrade without a reboot - more flexible support for bridge flooding via the compressed FID flooding mode - Ethernet embedded switches: - Microchip: - fine-tune flow control and speed configurations in KSZ8xxx - KSZ88X3: enable setting rmii reference - Renesas: - add jumbo frames support - Marvell: - 88E6xxx: add "eth-mac" and "rmon" stats support - Ethernet PHYs: - aquantia: add firmware load support - at803x: refactor the driver to simplify adding support for more chip variants - NXP C45 TJA11xx: Add MACsec offload support - Wifi: - MediaTek (mt76): - NVMEM EEPROM improvements - mt7996 Extremely High Throughput (EHT) improvements - mt7996 Wireless Ethernet Dispatcher (WED) support - mt7996 36-bit DMA support - Qualcomm (ath12k): - support for a single MSI vector - WCN7850: support AP mode - Intel (iwlwifi): - new debugfs file fw_dbg_clear - allow concurrent P2P operation on DFS channels - Bluetooth: - QCA2066: support HFP offload - ISO: more broadcast-related improvements - NXP: better recovery in case receiver/transmitter get out of sync" * tag 'net-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1714 commits) lan78xx: remove redundant statement in lan78xx_get_eee lan743x: remove redundant statement in lan743x_ethtool_get_eee bnxt_en: Fix RCU locking for ntuple filters in bnxt_rx_flow_steer() bnxt_en: Fix RCU locking for ntuple filters in bnxt_srxclsrldel() bnxt_en: Remove unneeded variable in bnxt_hwrm_clear_vnic_filter() tcp: Revert no longer abort SYN_SENT when receiving some ICMP Revert "mlx5 updates 2023-12-20" Revert "net: stmmac: Enable Per DMA Channel interrupt" ipvlan: Remove usage of the deprecated ida_simple_xx() API ipvlan: Fix a typo in a comment net/sched: Remove ipt action tests net: stmmac: Use interrupt mode INTM=1 for per channel irq net: stmmac: Add support for TX/RX channel interrupt net: stmmac: Make MSI interrupt routine generic dt-bindings: net: snps,dwmac: per channel irq net: phy: at803x: make read_status more generic net: phy: at803x: add support for cdt cross short test for qca808x net: phy: at803x: refactor qca808x cable test get status function net: phy: at803x: generalize cdt fault length function net: ethernet: cortina: Drop TSO support ...
Diffstat (limited to 'kernel/bpf')
-rw-r--r--kernel/bpf/arraymap.c35
-rw-r--r--kernel/bpf/bpf_cgrp_storage.c6
-rw-r--r--kernel/bpf/bpf_lsm.c12
-rw-r--r--kernel/bpf/bpf_struct_ops.c35
-rw-r--r--kernel/bpf/btf.c300
-rw-r--r--kernel/bpf/core.c50
-rw-r--r--kernel/bpf/cpumask.c20
-rw-r--r--kernel/bpf/dispatcher.c7
-rw-r--r--kernel/bpf/hashtab.c12
-rw-r--r--kernel/bpf/helpers.c78
-rw-r--r--kernel/bpf/inode.c53
-rw-r--r--kernel/bpf/log.c504
-rw-r--r--kernel/bpf/lpm_trie.c3
-rw-r--r--kernel/bpf/map_in_map.c17
-rw-r--r--kernel/bpf/map_in_map.h2
-rw-r--r--kernel/bpf/memalloc.c198
-rw-r--r--kernel/bpf/stackmap.c11
-rw-r--r--kernel/bpf/syscall.c114
-rw-r--r--kernel/bpf/task_iter.c29
-rw-r--r--kernel/bpf/tnum.c13
-rw-r--r--kernel/bpf/trampoline.c101
-rw-r--r--kernel/bpf/verifier.c2586
22 files changed, 2411 insertions, 1775 deletions
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index c85ff9162a5c..0bdbbbeab155 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -867,11 +867,11 @@ int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
}
if (old_ptr)
- map->ops->map_fd_put_ptr(old_ptr);
+ map->ops->map_fd_put_ptr(map, old_ptr, true);
return 0;
}
-static long fd_array_map_delete_elem(struct bpf_map *map, void *key)
+static long __fd_array_map_delete_elem(struct bpf_map *map, void *key, bool need_defer)
{
struct bpf_array *array = container_of(map, struct bpf_array, map);
void *old_ptr;
@@ -890,13 +890,18 @@ static long fd_array_map_delete_elem(struct bpf_map *map, void *key)
}
if (old_ptr) {
- map->ops->map_fd_put_ptr(old_ptr);
+ map->ops->map_fd_put_ptr(map, old_ptr, need_defer);
return 0;
} else {
return -ENOENT;
}
}
+static long fd_array_map_delete_elem(struct bpf_map *map, void *key)
+{
+ return __fd_array_map_delete_elem(map, key, true);
+}
+
static void *prog_fd_array_get_ptr(struct bpf_map *map,
struct file *map_file, int fd)
{
@@ -913,8 +918,9 @@ static void *prog_fd_array_get_ptr(struct bpf_map *map,
return prog;
}
-static void prog_fd_array_put_ptr(void *ptr)
+static void prog_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
{
+ /* bpf_prog is freed after one RCU or tasks trace grace period */
bpf_prog_put(ptr);
}
@@ -924,13 +930,13 @@ static u32 prog_fd_array_sys_lookup_elem(void *ptr)
}
/* decrement refcnt of all bpf_progs that are stored in this map */
-static void bpf_fd_array_map_clear(struct bpf_map *map)
+static void bpf_fd_array_map_clear(struct bpf_map *map, bool need_defer)
{
struct bpf_array *array = container_of(map, struct bpf_array, map);
int i;
for (i = 0; i < array->map.max_entries; i++)
- fd_array_map_delete_elem(map, &i);
+ __fd_array_map_delete_elem(map, &i, need_defer);
}
static void prog_array_map_seq_show_elem(struct bpf_map *map, void *key,
@@ -1071,7 +1077,7 @@ static void prog_array_map_clear_deferred(struct work_struct *work)
{
struct bpf_map *map = container_of(work, struct bpf_array_aux,
work)->map;
- bpf_fd_array_map_clear(map);
+ bpf_fd_array_map_clear(map, true);
bpf_map_put(map);
}
@@ -1151,7 +1157,7 @@ static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file,
{
struct bpf_event_entry *ee;
- ee = kzalloc(sizeof(*ee), GFP_ATOMIC);
+ ee = kzalloc(sizeof(*ee), GFP_KERNEL);
if (ee) {
ee->event = perf_file->private_data;
ee->perf_file = perf_file;
@@ -1201,8 +1207,9 @@ err_out:
return ee;
}
-static void perf_event_fd_array_put_ptr(void *ptr)
+static void perf_event_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
{
+ /* bpf_perf_event is freed after one RCU grace period */
bpf_event_entry_free_rcu(ptr);
}
@@ -1220,7 +1227,7 @@ static void perf_event_fd_array_release(struct bpf_map *map,
for (i = 0; i < array->map.max_entries; i++) {
ee = READ_ONCE(array->ptrs[i]);
if (ee && ee->map_file == map_file)
- fd_array_map_delete_elem(map, &i);
+ __fd_array_map_delete_elem(map, &i, true);
}
rcu_read_unlock();
}
@@ -1228,7 +1235,7 @@ static void perf_event_fd_array_release(struct bpf_map *map,
static void perf_event_fd_array_map_free(struct bpf_map *map)
{
if (map->map_flags & BPF_F_PRESERVE_ELEMS)
- bpf_fd_array_map_clear(map);
+ bpf_fd_array_map_clear(map, false);
fd_array_map_free(map);
}
@@ -1256,7 +1263,7 @@ static void *cgroup_fd_array_get_ptr(struct bpf_map *map,
return cgroup_get_from_fd(fd);
}
-static void cgroup_fd_array_put_ptr(void *ptr)
+static void cgroup_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
{
/* cgroup_put free cgrp after a rcu grace period */
cgroup_put(ptr);
@@ -1264,7 +1271,7 @@ static void cgroup_fd_array_put_ptr(void *ptr)
static void cgroup_fd_array_free(struct bpf_map *map)
{
- bpf_fd_array_map_clear(map);
+ bpf_fd_array_map_clear(map, false);
fd_array_map_free(map);
}
@@ -1309,7 +1316,7 @@ static void array_of_map_free(struct bpf_map *map)
* is protected by fdget/fdput.
*/
bpf_map_meta_free(map->inner_map_meta);
- bpf_fd_array_map_clear(map);
+ bpf_fd_array_map_clear(map, false);
fd_array_map_free(map);
}
diff --git a/kernel/bpf/bpf_cgrp_storage.c b/kernel/bpf/bpf_cgrp_storage.c
index d44fe8dd9732..28efd0a3f220 100644
--- a/kernel/bpf/bpf_cgrp_storage.c
+++ b/kernel/bpf/bpf_cgrp_storage.c
@@ -82,7 +82,7 @@ static void *bpf_cgrp_storage_lookup_elem(struct bpf_map *map, void *key)
int fd;
fd = *(int *)key;
- cgroup = cgroup_get_from_fd(fd);
+ cgroup = cgroup_v1v2_get_from_fd(fd);
if (IS_ERR(cgroup))
return ERR_CAST(cgroup);
@@ -101,7 +101,7 @@ static long bpf_cgrp_storage_update_elem(struct bpf_map *map, void *key,
int fd;
fd = *(int *)key;
- cgroup = cgroup_get_from_fd(fd);
+ cgroup = cgroup_v1v2_get_from_fd(fd);
if (IS_ERR(cgroup))
return PTR_ERR(cgroup);
@@ -131,7 +131,7 @@ static long bpf_cgrp_storage_delete_elem(struct bpf_map *map, void *key)
int err, fd;
fd = *(int *)key;
- cgroup = cgroup_get_from_fd(fd);
+ cgroup = cgroup_v1v2_get_from_fd(fd);
if (IS_ERR(cgroup))
return PTR_ERR(cgroup);
diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c
index e14c822f8911..e8e910395bf6 100644
--- a/kernel/bpf/bpf_lsm.c
+++ b/kernel/bpf/bpf_lsm.c
@@ -298,6 +298,18 @@ BTF_ID(func, bpf_lsm_kernel_module_request)
BTF_ID(func, bpf_lsm_kernel_read_file)
BTF_ID(func, bpf_lsm_kernfs_init_security)
+#ifdef CONFIG_SECURITY_PATH
+BTF_ID(func, bpf_lsm_path_unlink)
+BTF_ID(func, bpf_lsm_path_mkdir)
+BTF_ID(func, bpf_lsm_path_rmdir)
+BTF_ID(func, bpf_lsm_path_truncate)
+BTF_ID(func, bpf_lsm_path_symlink)
+BTF_ID(func, bpf_lsm_path_link)
+BTF_ID(func, bpf_lsm_path_rename)
+BTF_ID(func, bpf_lsm_path_chmod)
+BTF_ID(func, bpf_lsm_path_chown)
+#endif /* CONFIG_SECURITY_PATH */
+
#ifdef CONFIG_KEYS
BTF_ID(func, bpf_lsm_key_free)
#endif /* CONFIG_KEYS */
diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
index db6176fb64dc..02068bd0e4d9 100644
--- a/kernel/bpf/bpf_struct_ops.c
+++ b/kernel/bpf/bpf_struct_ops.c
@@ -352,18 +352,24 @@ const struct bpf_link_ops bpf_struct_ops_link_lops = {
int bpf_struct_ops_prepare_trampoline(struct bpf_tramp_links *tlinks,
struct bpf_tramp_link *link,
const struct btf_func_model *model,
- void *image, void *image_end)
+ void *stub_func, void *image, void *image_end)
{
- u32 flags;
+ u32 flags = BPF_TRAMP_F_INDIRECT;
+ int size;
tlinks[BPF_TRAMP_FENTRY].links[0] = link;
tlinks[BPF_TRAMP_FENTRY].nr_links = 1;
- /* BPF_TRAMP_F_RET_FENTRY_RET is only used by bpf_struct_ops,
- * and it must be used alone.
- */
- flags = model->ret_size > 0 ? BPF_TRAMP_F_RET_FENTRY_RET : 0;
+
+ if (model->ret_size > 0)
+ flags |= BPF_TRAMP_F_RET_FENTRY_RET;
+
+ size = arch_bpf_trampoline_size(model, flags, tlinks, NULL);
+ if (size < 0)
+ return size;
+ if (size > (unsigned long)image_end - (unsigned long)image)
+ return -E2BIG;
return arch_prepare_bpf_trampoline(NULL, image, image_end,
- model, flags, tlinks, NULL);
+ model, flags, tlinks, stub_func);
}
static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
@@ -497,11 +503,12 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
err = bpf_struct_ops_prepare_trampoline(tlinks, link,
&st_ops->func_models[i],
+ *(void **)(st_ops->cfi_stubs + moff),
image, image_end);
if (err < 0)
goto reset_unlock;
- *(void **)(kdata + moff) = image;
+ *(void **)(kdata + moff) = image + cfi_get_offset();
image += err;
/* put prog_id to udata */
@@ -515,7 +522,7 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
if (err)
goto reset_unlock;
}
- set_memory_rox((long)st_map->image, 1);
+ arch_protect_bpf_trampoline(st_map->image, PAGE_SIZE);
/* Let bpf_link handle registration & unregistration.
*
* Pair with smp_load_acquire() during lookup_elem().
@@ -524,7 +531,7 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
goto unlock;
}
- set_memory_rox((long)st_map->image, 1);
+ arch_protect_bpf_trampoline(st_map->image, PAGE_SIZE);
err = st_ops->reg(kdata);
if (likely(!err)) {
/* This refcnt increment on the map here after
@@ -547,8 +554,7 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
* there was a race in registering the struct_ops (under the same name) to
* a sub-system through different struct_ops's maps.
*/
- set_memory_nx((long)st_map->image, 1);
- set_memory_rw((long)st_map->image, 1);
+ arch_unprotect_bpf_trampoline(st_map->image, PAGE_SIZE);
reset_unlock:
bpf_struct_ops_map_put_progs(st_map);
@@ -616,7 +622,7 @@ static void __bpf_struct_ops_map_free(struct bpf_map *map)
bpf_struct_ops_map_put_progs(st_map);
bpf_map_area_free(st_map->links);
if (st_map->image) {
- bpf_jit_free_exec(st_map->image);
+ arch_free_bpf_trampoline(st_map->image, PAGE_SIZE);
bpf_jit_uncharge_modmem(PAGE_SIZE);
}
bpf_map_area_free(st_map->uvalue);
@@ -691,7 +697,7 @@ static struct bpf_map *bpf_struct_ops_map_alloc(union bpf_attr *attr)
return ERR_PTR(ret);
}
- st_map->image = bpf_jit_alloc_exec(PAGE_SIZE);
+ st_map->image = arch_alloc_bpf_trampoline(PAGE_SIZE);
if (!st_map->image) {
/* __bpf_struct_ops_map_free() uses st_map->image as flag
* for "charged or not". In this case, we need to unchange
@@ -711,7 +717,6 @@ static struct bpf_map *bpf_struct_ops_map_alloc(union bpf_attr *attr)
}
mutex_init(&st_map->lock);
- set_vm_flush_reset_perms(st_map->image);
bpf_map_init_from_attr(map, attr);
return map;
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 15d71d2986d3..51e8b4bee0c8 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -3840,9 +3840,6 @@ end:
return ERR_PTR(ret);
}
-#define GRAPH_ROOT_MASK (BPF_LIST_HEAD | BPF_RB_ROOT)
-#define GRAPH_NODE_MASK (BPF_LIST_NODE | BPF_RB_NODE)
-
int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec)
{
int i;
@@ -3855,13 +3852,13 @@ int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec)
* Hence we only need to ensure that bpf_{list_head,rb_root} ownership
* does not form cycles.
*/
- if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & GRAPH_ROOT_MASK))
+ if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & BPF_GRAPH_ROOT))
return 0;
for (i = 0; i < rec->cnt; i++) {
struct btf_struct_meta *meta;
u32 btf_id;
- if (!(rec->fields[i].type & GRAPH_ROOT_MASK))
+ if (!(rec->fields[i].type & BPF_GRAPH_ROOT))
continue;
btf_id = rec->fields[i].graph_root.value_btf_id;
meta = btf_find_struct_meta(btf, btf_id);
@@ -3873,7 +3870,7 @@ int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec)
* to check ownership cycle for a type unless it's also a
* node type.
*/
- if (!(rec->field_mask & GRAPH_NODE_MASK))
+ if (!(rec->field_mask & BPF_GRAPH_NODE))
continue;
/* We need to ensure ownership acyclicity among all types. The
@@ -3909,7 +3906,7 @@ int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec)
* - A is both an root and node.
* - B is only an node.
*/
- if (meta->record->field_mask & GRAPH_ROOT_MASK)
+ if (meta->record->field_mask & BPF_GRAPH_ROOT)
return -ELOOP;
}
return 0;
@@ -6768,222 +6765,64 @@ int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *pr
return btf_check_func_type_match(log, btf1, t1, btf2, t2);
}
-static int btf_check_func_arg_match(struct bpf_verifier_env *env,
- const struct btf *btf, u32 func_id,
- struct bpf_reg_state *regs,
- bool ptr_to_mem_ok,
- bool processing_call)
+static bool btf_is_dynptr_ptr(const struct btf *btf, const struct btf_type *t)
{
- enum bpf_prog_type prog_type = resolve_prog_type(env->prog);
- struct bpf_verifier_log *log = &env->log;
- const char *func_name, *ref_tname;
- const struct btf_type *t, *ref_t;
- const struct btf_param *args;
- u32 i, nargs, ref_id;
- int ret;
-
- t = btf_type_by_id(btf, func_id);
- if (!t || !btf_type_is_func(t)) {
- /* These checks were already done by the verifier while loading
- * struct bpf_func_info or in add_kfunc_call().
- */
- bpf_log(log, "BTF of func_id %u doesn't point to KIND_FUNC\n",
- func_id);
- return -EFAULT;
- }
- func_name = btf_name_by_offset(btf, t->name_off);
-
- t = btf_type_by_id(btf, t->type);
- if (!t || !btf_type_is_func_proto(t)) {
- bpf_log(log, "Invalid BTF of func %s\n", func_name);
- return -EFAULT;
- }
- args = (const struct btf_param *)(t + 1);
- nargs = btf_type_vlen(t);
- if (nargs > MAX_BPF_FUNC_REG_ARGS) {
- bpf_log(log, "Function %s has %d > %d args\n", func_name, nargs,
- MAX_BPF_FUNC_REG_ARGS);
- return -EINVAL;
- }
-
- /* check that BTF function arguments match actual types that the
- * verifier sees.
- */
- for (i = 0; i < nargs; i++) {
- enum bpf_arg_type arg_type = ARG_DONTCARE;
- u32 regno = i + 1;
- struct bpf_reg_state *reg = &regs[regno];
-
- t = btf_type_skip_modifiers(btf, args[i].type, NULL);
- if (btf_type_is_scalar(t)) {
- if (reg->type == SCALAR_VALUE)
- continue;
- bpf_log(log, "R%d is not a scalar\n", regno);
- return -EINVAL;
- }
-
- if (!btf_type_is_ptr(t)) {
- bpf_log(log, "Unrecognized arg#%d type %s\n",
- i, btf_type_str(t));
- return -EINVAL;
- }
-
- ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id);
- ref_tname = btf_name_by_offset(btf, ref_t->name_off);
-
- ret = check_func_arg_reg_off(env, reg, regno, arg_type);
- if (ret < 0)
- return ret;
+ const char *name;
- if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
- /* If function expects ctx type in BTF check that caller
- * is passing PTR_TO_CTX.
- */
- if (reg->type != PTR_TO_CTX) {
- bpf_log(log,
- "arg#%d expected pointer to ctx, but got %s\n",
- i, btf_type_str(t));
- return -EINVAL;
- }
- } else if (ptr_to_mem_ok && processing_call) {
- const struct btf_type *resolve_ret;
- u32 type_size;
+ t = btf_type_by_id(btf, t->type); /* skip PTR */
- resolve_ret = btf_resolve_size(btf, ref_t, &type_size);
- if (IS_ERR(resolve_ret)) {
- bpf_log(log,
- "arg#%d reference type('%s %s') size cannot be determined: %ld\n",
- i, btf_type_str(ref_t), ref_tname,
- PTR_ERR(resolve_ret));
- return -EINVAL;
- }
+ while (btf_type_is_modifier(t))
+ t = btf_type_by_id(btf, t->type);
- if (check_mem_reg(env, reg, regno, type_size))
- return -EINVAL;
- } else {
- bpf_log(log, "reg type unsupported for arg#%d function %s#%d\n", i,
- func_name, func_id);
- return -EINVAL;
- }
+ /* allow either struct or struct forward declaration */
+ if (btf_type_is_struct(t) ||
+ (btf_type_is_fwd(t) && btf_type_kflag(t) == 0)) {
+ name = btf_str_by_offset(btf, t->name_off);
+ return name && strcmp(name, "bpf_dynptr") == 0;
}
- return 0;
-}
-
-/* Compare BTF of a function declaration with given bpf_reg_state.
- * Returns:
- * EFAULT - there is a verifier bug. Abort verification.
- * EINVAL - there is a type mismatch or BTF is not available.
- * 0 - BTF matches with what bpf_reg_state expects.
- * Only PTR_TO_CTX and SCALAR_VALUE states are recognized.
- */
-int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog,
- struct bpf_reg_state *regs)
-{
- struct bpf_prog *prog = env->prog;
- struct btf *btf = prog->aux->btf;
- bool is_global;
- u32 btf_id;
- int err;
-
- if (!prog->aux->func_info)
- return -EINVAL;
-
- btf_id = prog->aux->func_info[subprog].type_id;
- if (!btf_id)
- return -EFAULT;
-
- if (prog->aux->func_info_aux[subprog].unreliable)
- return -EINVAL;
-
- is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL;
- err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, false);
-
- /* Compiler optimizations can remove arguments from static functions
- * or mismatched type can be passed into a global function.
- * In such cases mark the function as unreliable from BTF point of view.
- */
- if (err)
- prog->aux->func_info_aux[subprog].unreliable = true;
- return err;
-}
-
-/* Compare BTF of a function call with given bpf_reg_state.
- * Returns:
- * EFAULT - there is a verifier bug. Abort verification.
- * EINVAL - there is a type mismatch or BTF is not available.
- * 0 - BTF matches with what bpf_reg_state expects.
- * Only PTR_TO_CTX and SCALAR_VALUE states are recognized.
- *
- * NOTE: the code is duplicated from btf_check_subprog_arg_match()
- * because btf_check_func_arg_match() is still doing both. Once that
- * function is split in 2, we can call from here btf_check_subprog_arg_match()
- * first, and then treat the calling part in a new code path.
- */
-int btf_check_subprog_call(struct bpf_verifier_env *env, int subprog,
- struct bpf_reg_state *regs)
-{
- struct bpf_prog *prog = env->prog;
- struct btf *btf = prog->aux->btf;
- bool is_global;
- u32 btf_id;
- int err;
-
- if (!prog->aux->func_info)
- return -EINVAL;
-
- btf_id = prog->aux->func_info[subprog].type_id;
- if (!btf_id)
- return -EFAULT;
-
- if (prog->aux->func_info_aux[subprog].unreliable)
- return -EINVAL;
-
- is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL;
- err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, true);
-
- /* Compiler optimizations can remove arguments from static functions
- * or mismatched type can be passed into a global function.
- * In such cases mark the function as unreliable from BTF point of view.
- */
- if (err)
- prog->aux->func_info_aux[subprog].unreliable = true;
- return err;
+ return false;
}
-/* Convert BTF of a function into bpf_reg_state if possible
+/* Process BTF of a function to produce high-level expectation of function
+ * arguments (like ARG_PTR_TO_CTX, or ARG_PTR_TO_MEM, etc). This information
+ * is cached in subprog info for reuse.
* Returns:
* EFAULT - there is a verifier bug. Abort verification.
* EINVAL - cannot convert BTF.
- * 0 - Successfully converted BTF into bpf_reg_state
- * (either PTR_TO_CTX or SCALAR_VALUE).
+ * 0 - Successfully processed BTF and constructed argument expectations.
*/
-int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
- struct bpf_reg_state *regs, bool is_ex_cb)
+int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog)
{
+ bool is_global = subprog_aux(env, subprog)->linkage == BTF_FUNC_GLOBAL;
+ struct bpf_subprog_info *sub = subprog_info(env, subprog);
struct bpf_verifier_log *log = &env->log;
struct bpf_prog *prog = env->prog;
enum bpf_prog_type prog_type = prog->type;
struct btf *btf = prog->aux->btf;
const struct btf_param *args;
- const struct btf_type *t, *ref_t;
+ const struct btf_type *t, *ref_t, *fn_t;
u32 i, nargs, btf_id;
const char *tname;
- if (!prog->aux->func_info ||
- prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) {
+ if (sub->args_cached)
+ return 0;
+
+ if (!prog->aux->func_info) {
bpf_log(log, "Verifier bug\n");
return -EFAULT;
}
btf_id = prog->aux->func_info[subprog].type_id;
if (!btf_id) {
+ if (!is_global) /* not fatal for static funcs */
+ return -EINVAL;
bpf_log(log, "Global functions need valid BTF\n");
return -EFAULT;
}
- t = btf_type_by_id(btf, btf_id);
- if (!t || !btf_type_is_func(t)) {
+ fn_t = btf_type_by_id(btf, btf_id);
+ if (!fn_t || !btf_type_is_func(fn_t)) {
/* These checks were already done by the verifier while loading
* struct bpf_func_info
*/
@@ -6991,11 +6830,7 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
subprog);
return -EFAULT;
}
- tname = btf_name_by_offset(btf, t->name_off);
-
- if (log->level & BPF_LOG_LEVEL)
- bpf_log(log, "Validating %s() func#%d...\n",
- tname, subprog);
+ tname = btf_name_by_offset(btf, fn_t->name_off);
if (prog->aux->func_info_aux[subprog].unreliable) {
bpf_log(log, "Verifier bug in function %s()\n", tname);
@@ -7004,7 +6839,7 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
if (prog_type == BPF_PROG_TYPE_EXT)
prog_type = prog->aux->dst_prog->type;
- t = btf_type_by_id(btf, t->type);
+ t = btf_type_by_id(btf, fn_t->type);
if (!t || !btf_type_is_func_proto(t)) {
bpf_log(log, "Invalid type of function %s()\n", tname);
return -EFAULT;
@@ -7030,24 +6865,54 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
* Only PTR_TO_CTX and SCALAR are supported atm.
*/
for (i = 0; i < nargs; i++) {
- struct bpf_reg_state *reg = &regs[i + 1];
+ bool is_nonnull = false;
+ const char *tag;
t = btf_type_by_id(btf, args[i].type);
+
+ tag = btf_find_decl_tag_value(btf, fn_t, i, "arg:");
+ if (IS_ERR(tag) && PTR_ERR(tag) == -ENOENT) {
+ tag = NULL;
+ } else if (IS_ERR(tag)) {
+ bpf_log(log, "arg#%d type's tag fetching failure: %ld\n", i, PTR_ERR(tag));
+ return PTR_ERR(tag);
+ }
+ /* 'arg:<tag>' decl_tag takes precedence over derivation of
+ * register type from BTF type itself
+ */
+ if (tag) {
+ /* disallow arg tags in static subprogs */
+ if (!is_global) {
+ bpf_log(log, "arg#%d type tag is not supported in static functions\n", i);
+ return -EOPNOTSUPP;
+ }
+ if (strcmp(tag, "ctx") == 0) {
+ sub->args[i].arg_type = ARG_PTR_TO_CTX;
+ continue;
+ }
+ if (strcmp(tag, "nonnull") == 0)
+ is_nonnull = true;
+ }
+
while (btf_type_is_modifier(t))
t = btf_type_by_id(btf, t->type);
if (btf_type_is_int(t) || btf_is_any_enum(t)) {
- reg->type = SCALAR_VALUE;
+ sub->args[i].arg_type = ARG_ANYTHING;
continue;
}
- if (btf_type_is_ptr(t)) {
- if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
- reg->type = PTR_TO_CTX;
- continue;
- }
+ if (btf_type_is_ptr(t) && btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
+ sub->args[i].arg_type = ARG_PTR_TO_CTX;
+ continue;
+ }
+ if (btf_type_is_ptr(t) && btf_is_dynptr_ptr(btf, t)) {
+ sub->args[i].arg_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY;
+ continue;
+ }
+ if (is_global && btf_type_is_ptr(t)) {
+ u32 mem_size;
t = btf_type_skip_modifiers(btf, t->type, NULL);
-
- ref_t = btf_resolve_size(btf, t, &reg->mem_size);
+ ref_t = btf_resolve_size(btf, t, &mem_size);
if (IS_ERR(ref_t)) {
bpf_log(log,
"arg#%d reference type('%s %s') size cannot be determined: %ld\n",
@@ -7056,23 +6921,22 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
return -EINVAL;
}
- reg->type = PTR_TO_MEM | PTR_MAYBE_NULL;
- reg->id = ++env->id_gen;
-
+ sub->args[i].arg_type = is_nonnull ? ARG_PTR_TO_MEM : ARG_PTR_TO_MEM_OR_NULL;
+ sub->args[i].mem_size = mem_size;
continue;
}
+ if (is_nonnull) {
+ bpf_log(log, "arg#%d marked as non-null, but is not a pointer type\n", i);
+ return -EINVAL;
+ }
bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n",
i, btf_type_str(t), tname);
return -EINVAL;
}
- /* We have already ensured that the callback returns an integer, just
- * like all global subprogs. We need to determine it only has a single
- * scalar argument.
- */
- if (is_ex_cb && (nargs != 1 || regs[BPF_REG_1].type != SCALAR_VALUE)) {
- bpf_log(log, "exception cb only supports single integer argument\n");
- return -EINVAL;
- }
+
+ sub->arg_cnt = nargs;
+ sub->args_cached = true;
+
return 0;
}
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index fe254ae035fe..ea6843be2616 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -121,6 +121,9 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag
#endif
INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
+#ifdef CONFIG_FINEIBT
+ INIT_LIST_HEAD_RCU(&fp->aux->ksym_prefix.lnode);
+#endif
mutex_init(&fp->aux->used_maps_mutex);
mutex_init(&fp->aux->dst_mutex);
@@ -687,6 +690,23 @@ void bpf_prog_kallsyms_add(struct bpf_prog *fp)
fp->aux->ksym.prog = true;
bpf_ksym_add(&fp->aux->ksym);
+
+#ifdef CONFIG_FINEIBT
+ /*
+ * When FineIBT, code in the __cfi_foo() symbols can get executed
+ * and hence unwinder needs help.
+ */
+ if (cfi_mode != CFI_FINEIBT)
+ return;
+
+ snprintf(fp->aux->ksym_prefix.name, KSYM_NAME_LEN,
+ "__cfi_%s", fp->aux->ksym.name);
+
+ fp->aux->ksym_prefix.start = (unsigned long) fp->bpf_func - 16;
+ fp->aux->ksym_prefix.end = (unsigned long) fp->bpf_func;
+
+ bpf_ksym_add(&fp->aux->ksym_prefix);
+#endif
}
void bpf_prog_kallsyms_del(struct bpf_prog *fp)
@@ -695,6 +715,11 @@ void bpf_prog_kallsyms_del(struct bpf_prog *fp)
return;
bpf_ksym_del(&fp->aux->ksym);
+#ifdef CONFIG_FINEIBT
+ if (cfi_mode != CFI_FINEIBT)
+ return;
+ bpf_ksym_del(&fp->aux->ksym_prefix);
+#endif
}
static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
@@ -932,20 +957,20 @@ out:
return ptr;
}
-void bpf_prog_pack_free(struct bpf_binary_header *hdr)
+void bpf_prog_pack_free(void *ptr, u32 size)
{
struct bpf_prog_pack *pack = NULL, *tmp;
unsigned int nbits;
unsigned long pos;
mutex_lock(&pack_mutex);
- if (hdr->size > BPF_PROG_PACK_SIZE) {
- bpf_jit_free_exec(hdr);
+ if (size > BPF_PROG_PACK_SIZE) {
+ bpf_jit_free_exec(ptr);
goto out;
}
list_for_each_entry(tmp, &pack_list, list) {
- if ((void *)hdr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > (void *)hdr) {
+ if (ptr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > ptr) {
pack = tmp;
break;
}
@@ -954,10 +979,10 @@ void bpf_prog_pack_free(struct bpf_binary_header *hdr)
if (WARN_ONCE(!pack, "bpf_prog_pack bug\n"))
goto out;
- nbits = BPF_PROG_SIZE_TO_NBITS(hdr->size);
- pos = ((unsigned long)hdr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT;
+ nbits = BPF_PROG_SIZE_TO_NBITS(size);
+ pos = ((unsigned long)ptr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT;
- WARN_ONCE(bpf_arch_text_invalidate(hdr, hdr->size),
+ WARN_ONCE(bpf_arch_text_invalidate(ptr, size),
"bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n");
bitmap_clear(pack->bitmap, pos, nbits);
@@ -1104,8 +1129,7 @@ bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
*rw_header = kvmalloc(size, GFP_KERNEL);
if (!*rw_header) {
- bpf_arch_text_copy(&ro_header->size, &size, sizeof(size));
- bpf_prog_pack_free(ro_header);
+ bpf_prog_pack_free(ro_header, size);
bpf_jit_uncharge_modmem(size);
return NULL;
}
@@ -1136,7 +1160,7 @@ int bpf_jit_binary_pack_finalize(struct bpf_prog *prog,
kvfree(rw_header);
if (IS_ERR(ptr)) {
- bpf_prog_pack_free(ro_header);
+ bpf_prog_pack_free(ro_header, ro_header->size);
return PTR_ERR(ptr);
}
return 0;
@@ -1157,7 +1181,7 @@ void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header,
{
u32 size = ro_header->size;
- bpf_prog_pack_free(ro_header);
+ bpf_prog_pack_free(ro_header, size);
kvfree(rw_header);
bpf_jit_uncharge_modmem(size);
}
@@ -2668,12 +2692,16 @@ void __bpf_free_used_maps(struct bpf_prog_aux *aux,
struct bpf_map **used_maps, u32 len)
{
struct bpf_map *map;
+ bool sleepable;
u32 i;
+ sleepable = aux->sleepable;
for (i = 0; i < len; i++) {
map = used_maps[i];
if (map->ops->map_poke_untrack)
map->ops->map_poke_untrack(map, aux);
+ if (sleepable)
+ atomic64_dec(&map->sleepable_refcnt);
bpf_map_put(map);
}
}
diff --git a/kernel/bpf/cpumask.c b/kernel/bpf/cpumask.c
index e01c741e54e7..2e73533a3811 100644
--- a/kernel/bpf/cpumask.c
+++ b/kernel/bpf/cpumask.c
@@ -96,6 +96,12 @@ __bpf_kfunc void bpf_cpumask_release(struct bpf_cpumask *cpumask)
migrate_enable();
}
+__bpf_kfunc void bpf_cpumask_release_dtor(void *cpumask)
+{
+ bpf_cpumask_release(cpumask);
+}
+CFI_NOSEAL(bpf_cpumask_release_dtor);
+
/**
* bpf_cpumask_first() - Get the index of the first nonzero bit in the cpumask.
* @cpumask: The cpumask being queried.
@@ -405,6 +411,17 @@ __bpf_kfunc u32 bpf_cpumask_any_and_distribute(const struct cpumask *src1,
return cpumask_any_and_distribute(src1, src2);
}
+/**
+ * bpf_cpumask_weight() - Return the number of bits in @cpumask.
+ * @cpumask: The cpumask being queried.
+ *
+ * Count the number of set bits in the given cpumask.
+ */
+__bpf_kfunc u32 bpf_cpumask_weight(const struct cpumask *cpumask)
+{
+ return cpumask_weight(cpumask);
+}
+
__bpf_kfunc_end_defs();
BTF_SET8_START(cpumask_kfunc_btf_ids)
@@ -432,6 +449,7 @@ BTF_ID_FLAGS(func, bpf_cpumask_full, KF_RCU)
BTF_ID_FLAGS(func, bpf_cpumask_copy, KF_RCU)
BTF_ID_FLAGS(func, bpf_cpumask_any_distribute, KF_RCU)
BTF_ID_FLAGS(func, bpf_cpumask_any_and_distribute, KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_weight, KF_RCU)
BTF_SET8_END(cpumask_kfunc_btf_ids)
static const struct btf_kfunc_id_set cpumask_kfunc_set = {
@@ -441,7 +459,7 @@ static const struct btf_kfunc_id_set cpumask_kfunc_set = {
BTF_ID_LIST(cpumask_dtor_ids)
BTF_ID(struct, bpf_cpumask)
-BTF_ID(func, bpf_cpumask_release)
+BTF_ID(func, bpf_cpumask_release_dtor)
static int __init cpumask_kfunc_init(void)
{
diff --git a/kernel/bpf/dispatcher.c b/kernel/bpf/dispatcher.c
index fa3e9225aedc..70fb82bf1637 100644
--- a/kernel/bpf/dispatcher.c
+++ b/kernel/bpf/dispatcher.c
@@ -150,14 +150,11 @@ void bpf_dispatcher_change_prog(struct bpf_dispatcher *d, struct bpf_prog *from,
goto out;
d->rw_image = bpf_jit_alloc_exec(PAGE_SIZE);
if (!d->rw_image) {
- u32 size = PAGE_SIZE;
-
- bpf_arch_text_copy(d->image, &size, sizeof(size));
- bpf_prog_pack_free((struct bpf_binary_header *)d->image);
+ bpf_prog_pack_free(d->image, PAGE_SIZE);
d->image = NULL;
goto out;
}
- bpf_image_ksym_add(d->image, &d->ksym);
+ bpf_image_ksym_add(d->image, PAGE_SIZE, &d->ksym);
}
prev_num_progs = d->num_progs;
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 3ba98ed2b3f9..03a6a2500b6a 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -898,7 +898,7 @@ static void htab_put_fd_value(struct bpf_htab *htab, struct htab_elem *l)
if (map->ops->map_fd_put_ptr) {
ptr = fd_htab_map_get_ptr(map, l);
- map->ops->map_fd_put_ptr(ptr);
+ map->ops->map_fd_put_ptr(map, ptr, true);
}
}
@@ -2485,7 +2485,7 @@ static void fd_htab_map_free(struct bpf_map *map)
hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
void *ptr = fd_htab_map_get_ptr(map, l);
- map->ops->map_fd_put_ptr(ptr);
+ map->ops->map_fd_put_ptr(map, ptr, false);
}
}
@@ -2524,9 +2524,15 @@ int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file,
if (IS_ERR(ptr))
return PTR_ERR(ptr);
+ /* The htab bucket lock is always held during update operations in fd
+ * htab map, and the following rcu_read_lock() is only used to avoid
+ * the WARN_ON_ONCE in htab_map_update_elem().
+ */
+ rcu_read_lock();
ret = htab_map_update_elem(map, key, &ptr, map_flags);
+ rcu_read_unlock();
if (ret)
- map->ops->map_fd_put_ptr(ptr);
+ map->ops->map_fd_put_ptr(map, ptr, false);
return ret;
}
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 56b0c1f678ee..be72824f32b2 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -32,12 +32,13 @@
*
* Different map implementations will rely on rcu in map methods
* lookup/update/delete, therefore eBPF programs must run under rcu lock
- * if program is allowed to access maps, so check rcu_read_lock_held in
- * all three functions.
+ * if program is allowed to access maps, so check rcu_read_lock_held() or
+ * rcu_read_lock_trace_held() in all three functions.
*/
BPF_CALL_2(bpf_map_lookup_elem, struct bpf_map *, map, void *, key)
{
- WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
+ WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
+ !rcu_read_lock_bh_held());
return (unsigned long) map->ops->map_lookup_elem(map, key);
}
@@ -53,7 +54,8 @@ const struct bpf_func_proto bpf_map_lookup_elem_proto = {
BPF_CALL_4(bpf_map_update_elem, struct bpf_map *, map, void *, key,
void *, value, u64, flags)
{
- WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
+ WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
+ !rcu_read_lock_bh_held());
return map->ops->map_update_elem(map, key, value, flags);
}
@@ -70,7 +72,8 @@ const struct bpf_func_proto bpf_map_update_elem_proto = {
BPF_CALL_2(bpf_map_delete_elem, struct bpf_map *, map, void *, key)
{
- WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
+ WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
+ !rcu_read_lock_bh_held());
return map->ops->map_delete_elem(map, key);
}
@@ -1937,10 +1940,7 @@ void __bpf_obj_drop_impl(void *p, const struct btf_record *rec, bool percpu)
ma = &bpf_global_percpu_ma;
else
ma = &bpf_global_ma;
- if (rec && rec->refcount_off >= 0)
- bpf_mem_free_rcu(ma, p);
- else
- bpf_mem_free(ma, p);
+ bpf_mem_free_rcu(ma, p);
}
__bpf_kfunc void bpf_obj_drop_impl(void *p__alloc, void *meta__ign)
@@ -2150,6 +2150,12 @@ __bpf_kfunc void bpf_task_release(struct task_struct *p)
put_task_struct_rcu_user(p);
}
+__bpf_kfunc void bpf_task_release_dtor(void *p)
+{
+ put_task_struct_rcu_user(p);
+}
+CFI_NOSEAL(bpf_task_release_dtor);
+
#ifdef CONFIG_CGROUPS
/**
* bpf_cgroup_acquire - Acquire a reference to a cgroup. A cgroup acquired by
@@ -2174,6 +2180,12 @@ __bpf_kfunc void bpf_cgroup_release(struct cgroup *cgrp)
cgroup_put(cgrp);
}
+__bpf_kfunc void bpf_cgroup_release_dtor(void *cgrp)
+{
+ cgroup_put(cgrp);
+}
+CFI_NOSEAL(bpf_cgroup_release_dtor);
+
/**
* bpf_cgroup_ancestor - Perform a lookup on an entry in a cgroup's ancestor
* array. A cgroup returned by this kfunc which is not subsequently stored in a
@@ -2231,6 +2243,25 @@ __bpf_kfunc long bpf_task_under_cgroup(struct task_struct *task,
rcu_read_unlock();
return ret;
}
+
+/**
+ * bpf_task_get_cgroup1 - Acquires the associated cgroup of a task within a
+ * specific cgroup1 hierarchy. The cgroup1 hierarchy is identified by its
+ * hierarchy ID.
+ * @task: The target task
+ * @hierarchy_id: The ID of a cgroup1 hierarchy
+ *
+ * On success, the cgroup is returen. On failure, NULL is returned.
+ */
+__bpf_kfunc struct cgroup *
+bpf_task_get_cgroup1(struct task_struct *task, int hierarchy_id)
+{
+ struct cgroup *cgrp = task_get_cgroup1(task, hierarchy_id);
+
+ if (IS_ERR(cgrp))
+ return NULL;
+ return cgrp;
+}
#endif /* CONFIG_CGROUPS */
/**
@@ -2506,7 +2537,7 @@ __bpf_kfunc void bpf_throw(u64 cookie)
* which skips compiler generated instrumentation to do the same.
*/
kasan_unpoison_task_stack_below((void *)(long)ctx.sp);
- ctx.aux->bpf_exception_cb(cookie, ctx.sp, ctx.bp);
+ ctx.aux->bpf_exception_cb(cookie, ctx.sp, ctx.bp, 0, 0);
WARN(1, "A call to BPF exception callback should never return\n");
}
@@ -2520,7 +2551,7 @@ BTF_ID_FLAGS(func, bpf_obj_new_impl, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_percpu_obj_new_impl, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_obj_drop_impl, KF_RELEASE)
BTF_ID_FLAGS(func, bpf_percpu_obj_drop_impl, KF_RELEASE)
-BTF_ID_FLAGS(func, bpf_refcount_acquire_impl, KF_ACQUIRE | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_refcount_acquire_impl, KF_ACQUIRE | KF_RET_NULL | KF_RCU)
BTF_ID_FLAGS(func, bpf_list_push_front_impl)
BTF_ID_FLAGS(func, bpf_list_push_back_impl)
BTF_ID_FLAGS(func, bpf_list_pop_front, KF_ACQUIRE | KF_RET_NULL)
@@ -2537,6 +2568,7 @@ BTF_ID_FLAGS(func, bpf_cgroup_release, KF_RELEASE)
BTF_ID_FLAGS(func, bpf_cgroup_ancestor, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_cgroup_from_id, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_task_under_cgroup, KF_RCU)
+BTF_ID_FLAGS(func, bpf_task_get_cgroup1, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
#endif
BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_throw)
@@ -2550,10 +2582,10 @@ static const struct btf_kfunc_id_set generic_kfunc_set = {
BTF_ID_LIST(generic_dtor_ids)
BTF_ID(struct, task_struct)
-BTF_ID(func, bpf_task_release)
+BTF_ID(func, bpf_task_release_dtor)
#ifdef CONFIG_CGROUPS
BTF_ID(struct, cgroup)
-BTF_ID(func, bpf_cgroup_release)
+BTF_ID(func, bpf_cgroup_release_dtor)
#endif
BTF_SET8_START(common_btf_ids)
@@ -2610,6 +2642,7 @@ static int __init kfunc_init(void)
ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &generic_kfunc_set);
ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &generic_kfunc_set);
+ ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &generic_kfunc_set);
ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &generic_kfunc_set);
ret = ret ?: register_btf_id_dtor_kfuncs(generic_dtors,
ARRAY_SIZE(generic_dtors),
@@ -2618,3 +2651,22 @@ static int __init kfunc_init(void)
}
late_initcall(kfunc_init);
+
+/* Get a pointer to dynptr data up to len bytes for read only access. If
+ * the dynptr doesn't have continuous data up to len bytes, return NULL.
+ */
+const void *__bpf_dynptr_data(const struct bpf_dynptr_kern *ptr, u32 len)
+{
+ return bpf_dynptr_slice(ptr, 0, NULL, len);
+}
+
+/* Get a pointer to dynptr data up to len bytes for read write access. If
+ * the dynptr doesn't have continuous data up to len bytes, or the dynptr
+ * is read only, return NULL.
+ */
+void *__bpf_dynptr_data_rw(const struct bpf_dynptr_kern *ptr, u32 len)
+{
+ if (__bpf_dynptr_is_rdonly(ptr))
+ return NULL;
+ return (void *)__bpf_dynptr_data(ptr, len);
+}
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index 1aafb2ff2e95..41e0a55c35f5 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -599,8 +599,15 @@ EXPORT_SYMBOL(bpf_prog_get_type_path);
*/
static int bpf_show_options(struct seq_file *m, struct dentry *root)
{
- umode_t mode = d_inode(root)->i_mode & S_IALLUGO & ~S_ISVTX;
-
+ struct inode *inode = d_inode(root);
+ umode_t mode = inode->i_mode & S_IALLUGO & ~S_ISVTX;
+
+ if (!uid_eq(inode->i_uid, GLOBAL_ROOT_UID))
+ seq_printf(m, ",uid=%u",
+ from_kuid_munged(&init_user_ns, inode->i_uid));
+ if (!gid_eq(inode->i_gid, GLOBAL_ROOT_GID))
+ seq_printf(m, ",gid=%u",
+ from_kgid_munged(&init_user_ns, inode->i_gid));
if (mode != S_IRWXUGO)
seq_printf(m, ",mode=%o", mode);
return 0;
@@ -625,15 +632,21 @@ static const struct super_operations bpf_super_ops = {
};
enum {
+ OPT_UID,
+ OPT_GID,
OPT_MODE,
};
static const struct fs_parameter_spec bpf_fs_parameters[] = {
+ fsparam_u32 ("uid", OPT_UID),
+ fsparam_u32 ("gid", OPT_GID),
fsparam_u32oct ("mode", OPT_MODE),
{}
};
struct bpf_mount_opts {
+ kuid_t uid;
+ kgid_t gid;
umode_t mode;
};
@@ -641,6 +654,8 @@ static int bpf_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
struct bpf_mount_opts *opts = fc->fs_private;
struct fs_parse_result result;
+ kuid_t uid;
+ kgid_t gid;
int opt;
opt = fs_parse(fc, bpf_fs_parameters, param, &result);
@@ -662,12 +677,42 @@ static int bpf_parse_param(struct fs_context *fc, struct fs_parameter *param)
}
switch (opt) {
+ case OPT_UID:
+ uid = make_kuid(current_user_ns(), result.uint_32);
+ if (!uid_valid(uid))
+ goto bad_value;
+
+ /*
+ * The requested uid must be representable in the
+ * filesystem's idmapping.
+ */
+ if (!kuid_has_mapping(fc->user_ns, uid))
+ goto bad_value;
+
+ opts->uid = uid;
+ break;
+ case OPT_GID:
+ gid = make_kgid(current_user_ns(), result.uint_32);
+ if (!gid_valid(gid))
+ goto bad_value;
+
+ /*
+ * The requested gid must be representable in the
+ * filesystem's idmapping.
+ */
+ if (!kgid_has_mapping(fc->user_ns, gid))
+ goto bad_value;
+
+ opts->gid = gid;
+ break;
case OPT_MODE:
opts->mode = result.uint_32 & S_IALLUGO;
break;
}
return 0;
+bad_value:
+ return invalfc(fc, "Bad value for '%s'", param->key);
}
struct bpf_preload_ops *bpf_preload_ops;
@@ -750,6 +795,8 @@ static int bpf_fill_super(struct super_block *sb, struct fs_context *fc)
sb->s_op = &bpf_super_ops;
inode = sb->s_root->d_inode;
+ inode->i_uid = opts->uid;
+ inode->i_gid = opts->gid;
inode->i_op = &bpf_dir_iops;
inode->i_mode &= ~S_IALLUGO;
populate_bpffs(sb->s_root);
@@ -785,6 +832,8 @@ static int bpf_init_fs_context(struct fs_context *fc)
return -ENOMEM;
opts->mode = S_IRWXUGO;
+ opts->uid = current_fsuid();
+ opts->gid = current_fsgid();
fc->fs_private = opts;
fc->ops = &bpf_context_ops;
diff --git a/kernel/bpf/log.c b/kernel/bpf/log.c
index 850494423530..594a234f122b 100644
--- a/kernel/bpf/log.c
+++ b/kernel/bpf/log.c
@@ -10,6 +10,8 @@
#include <linux/bpf_verifier.h>
#include <linux/math64.h>
+#define verbose(env, fmt, args...) bpf_verifier_log_write(env, fmt, ##args)
+
static bool bpf_verifier_log_attr_valid(const struct bpf_verifier_log *log)
{
/* ubuf and len_total should both be specified (or not) together */
@@ -325,3 +327,505 @@ __printf(2, 3) void bpf_log(struct bpf_verifier_log *log,
va_end(args);
}
EXPORT_SYMBOL_GPL(bpf_log);
+
+static const struct bpf_line_info *
+find_linfo(const struct bpf_verifier_env *env, u32 insn_off)
+{
+ const struct bpf_line_info *linfo;
+ const struct bpf_prog *prog;
+ u32 i, nr_linfo;
+
+ prog = env->prog;
+ nr_linfo = prog->aux->nr_linfo;
+
+ if (!nr_linfo || insn_off >= prog->len)
+ return NULL;
+
+ linfo = prog->aux->linfo;
+ for (i = 1; i < nr_linfo; i++)
+ if (insn_off < linfo[i].insn_off)
+ break;
+
+ return &linfo[i - 1];
+}
+
+static const char *ltrim(const char *s)
+{
+ while (isspace(*s))
+ s++;
+
+ return s;
+}
+
+__printf(3, 4) void verbose_linfo(struct bpf_verifier_env *env,
+ u32 insn_off,
+ const char *prefix_fmt, ...)
+{
+ const struct bpf_line_info *linfo;
+
+ if (!bpf_verifier_log_needed(&env->log))
+ return;
+
+ linfo = find_linfo(env, insn_off);
+ if (!linfo || linfo == env->prev_linfo)
+ return;
+
+ if (prefix_fmt) {
+ va_list args;
+
+ va_start(args, prefix_fmt);
+ bpf_verifier_vlog(&env->log, prefix_fmt, args);
+ va_end(args);
+ }
+
+ verbose(env, "%s\n",
+ ltrim(btf_name_by_offset(env->prog->aux->btf,
+ linfo->line_off)));
+
+ env->prev_linfo = linfo;
+}
+
+static const char *btf_type_name(const struct btf *btf, u32 id)
+{
+ return btf_name_by_offset(btf, btf_type_by_id(btf, id)->name_off);
+}
+
+/* string representation of 'enum bpf_reg_type'
+ *
+ * Note that reg_type_str() can not appear more than once in a single verbose()
+ * statement.
+ */
+const char *reg_type_str(struct bpf_verifier_env *env, enum bpf_reg_type type)
+{
+ char postfix[16] = {0}, prefix[64] = {0};
+ static const char * const str[] = {
+ [NOT_INIT] = "?",
+ [SCALAR_VALUE] = "scalar",
+ [PTR_TO_CTX] = "ctx",
+ [CONST_PTR_TO_MAP] = "map_ptr",
+ [PTR_TO_MAP_VALUE] = "map_value",
+ [PTR_TO_STACK] = "fp",
+ [PTR_TO_PACKET] = "pkt",
+ [PTR_TO_PACKET_META] = "pkt_meta",
+ [PTR_TO_PACKET_END] = "pkt_end",
+ [PTR_TO_FLOW_KEYS] = "flow_keys",
+ [PTR_TO_SOCKET] = "sock",
+ [PTR_TO_SOCK_COMMON] = "sock_common",
+ [PTR_TO_TCP_SOCK] = "tcp_sock",
+ [PTR_TO_TP_BUFFER] = "tp_buffer",
+ [PTR_TO_XDP_SOCK] = "xdp_sock",
+ [PTR_TO_BTF_ID] = "ptr_",
+ [PTR_TO_MEM] = "mem",
+ [PTR_TO_BUF] = "buf",
+ [PTR_TO_FUNC] = "func",
+ [PTR_TO_MAP_KEY] = "map_key",
+ [CONST_PTR_TO_DYNPTR] = "dynptr_ptr",
+ };
+
+ if (type & PTR_MAYBE_NULL) {
+ if (base_type(type) == PTR_TO_BTF_ID)
+ strncpy(postfix, "or_null_", 16);
+ else
+ strncpy(postfix, "_or_null", 16);
+ }
+
+ snprintf(prefix, sizeof(prefix), "%s%s%s%s%s%s%s",
+ type & MEM_RDONLY ? "rdonly_" : "",
+ type & MEM_RINGBUF ? "ringbuf_" : "",
+ type & MEM_USER ? "user_" : "",
+ type & MEM_PERCPU ? "percpu_" : "",
+ type & MEM_RCU ? "rcu_" : "",
+ type & PTR_UNTRUSTED ? "untrusted_" : "",
+ type & PTR_TRUSTED ? "trusted_" : ""
+ );
+
+ snprintf(env->tmp_str_buf, TMP_STR_BUF_LEN, "%s%s%s",
+ prefix, str[base_type(type)], postfix);
+ return env->tmp_str_buf;
+}
+
+const char *dynptr_type_str(enum bpf_dynptr_type type)
+{
+ switch (type) {
+ case BPF_DYNPTR_TYPE_LOCAL:
+ return "local";
+ case BPF_DYNPTR_TYPE_RINGBUF:
+ return "ringbuf";
+ case BPF_DYNPTR_TYPE_SKB:
+ return "skb";
+ case BPF_DYNPTR_TYPE_XDP:
+ return "xdp";
+ case BPF_DYNPTR_TYPE_INVALID:
+ return "<invalid>";
+ default:
+ WARN_ONCE(1, "unknown dynptr type %d\n", type);
+ return "<unknown>";
+ }
+}
+
+const char *iter_type_str(const struct btf *btf, u32 btf_id)
+{
+ if (!btf || btf_id == 0)
+ return "<invalid>";
+
+ /* we already validated that type is valid and has conforming name */
+ return btf_type_name(btf, btf_id) + sizeof(ITER_PREFIX) - 1;
+}
+
+const char *iter_state_str(enum bpf_iter_state state)
+{
+ switch (state) {
+ case BPF_ITER_STATE_ACTIVE:
+ return "active";
+ case BPF_ITER_STATE_DRAINED:
+ return "drained";
+ case BPF_ITER_STATE_INVALID:
+ return "<invalid>";
+ default:
+ WARN_ONCE(1, "unknown iter state %d\n", state);
+ return "<unknown>";
+ }
+}
+
+static char slot_type_char[] = {
+ [STACK_INVALID] = '?',
+ [STACK_SPILL] = 'r',
+ [STACK_MISC] = 'm',
+ [STACK_ZERO] = '0',
+ [STACK_DYNPTR] = 'd',
+ [STACK_ITER] = 'i',
+};
+
+static void print_liveness(struct bpf_verifier_env *env,
+ enum bpf_reg_liveness live)
+{
+ if (live & (REG_LIVE_READ | REG_LIVE_WRITTEN | REG_LIVE_DONE))
+ verbose(env, "_");
+ if (live & REG_LIVE_READ)
+ verbose(env, "r");
+ if (live & REG_LIVE_WRITTEN)
+ verbose(env, "w");
+ if (live & REG_LIVE_DONE)
+ verbose(env, "D");
+}
+
+#define UNUM_MAX_DECIMAL U16_MAX
+#define SNUM_MAX_DECIMAL S16_MAX
+#define SNUM_MIN_DECIMAL S16_MIN
+
+static bool is_unum_decimal(u64 num)
+{
+ return num <= UNUM_MAX_DECIMAL;
+}
+
+static bool is_snum_decimal(s64 num)
+{
+ return num >= SNUM_MIN_DECIMAL && num <= SNUM_MAX_DECIMAL;
+}
+
+static void verbose_unum(struct bpf_verifier_env *env, u64 num)
+{
+ if (is_unum_decimal(num))
+ verbose(env, "%llu", num);
+ else
+ verbose(env, "%#llx", num);
+}
+
+static void verbose_snum(struct bpf_verifier_env *env, s64 num)
+{
+ if (is_snum_decimal(num))
+ verbose(env, "%lld", num);
+ else
+ verbose(env, "%#llx", num);
+}
+
+int tnum_strn(char *str, size_t size, struct tnum a)
+{
+ /* print as a constant, if tnum is fully known */
+ if (a.mask == 0) {
+ if (is_unum_decimal(a.value))
+ return snprintf(str, size, "%llu", a.value);
+ else
+ return snprintf(str, size, "%#llx", a.value);
+ }
+ return snprintf(str, size, "(%#llx; %#llx)", a.value, a.mask);
+}
+EXPORT_SYMBOL_GPL(tnum_strn);
+
+static void print_scalar_ranges(struct bpf_verifier_env *env,
+ const struct bpf_reg_state *reg,
+ const char **sep)
+{
+ /* For signed ranges, we want to unify 64-bit and 32-bit values in the
+ * output as much as possible, but there is a bit of a complication.
+ * If we choose to print values as decimals, this is natural to do,
+ * because negative 64-bit and 32-bit values >= -S32_MIN have the same
+ * representation due to sign extension. But if we choose to print
+ * them in hex format (see is_snum_decimal()), then sign extension is
+ * misleading.
+ * E.g., smin=-2 and smin32=-2 are exactly the same in decimal, but in
+ * hex they will be smin=0xfffffffffffffffe and smin32=0xfffffffe, two
+ * very different numbers.
+ * So we avoid sign extension if we choose to print values in hex.
+ */
+ struct {
+ const char *name;
+ u64 val;
+ bool omit;
+ } minmaxs[] = {
+ {"smin", reg->smin_value, reg->smin_value == S64_MIN},
+ {"smax", reg->smax_value, reg->smax_value == S64_MAX},
+ {"umin", reg->umin_value, reg->umin_value == 0},
+ {"umax", reg->umax_value, reg->umax_value == U64_MAX},
+ {"smin32",
+ is_snum_decimal((s64)reg->s32_min_value)
+ ? (s64)reg->s32_min_value
+ : (u32)reg->s32_min_value, reg->s32_min_value == S32_MIN},
+ {"smax32",
+ is_snum_decimal((s64)reg->s32_max_value)
+ ? (s64)reg->s32_max_value
+ : (u32)reg->s32_max_value, reg->s32_max_value == S32_MAX},
+ {"umin32", reg->u32_min_value, reg->u32_min_value == 0},
+ {"umax32", reg->u32_max_value, reg->u32_max_value == U32_MAX},
+ }, *m1, *m2, *mend = &minmaxs[ARRAY_SIZE(minmaxs)];
+ bool neg1, neg2;
+
+ for (m1 = &minmaxs[0]; m1 < mend; m1++) {
+ if (m1->omit)
+ continue;
+
+ neg1 = m1->name[0] == 's' && (s64)m1->val < 0;
+
+ verbose(env, "%s%s=", *sep, m1->name);
+ *sep = ",";
+
+ for (m2 = m1 + 2; m2 < mend; m2 += 2) {
+ if (m2->omit || m2->val != m1->val)
+ continue;
+ /* don't mix negatives with positives */
+ neg2 = m2->name[0] == 's' && (s64)m2->val < 0;
+ if (neg2 != neg1)
+ continue;
+ m2->omit = true;
+ verbose(env, "%s=", m2->name);
+ }
+
+ if (m1->name[0] == 's')
+ verbose_snum(env, m1->val);
+ else
+ verbose_unum(env, m1->val);
+ }
+}
+
+static bool type_is_map_ptr(enum bpf_reg_type t) {
+ switch (base_type(t)) {
+ case CONST_PTR_TO_MAP:
+ case PTR_TO_MAP_KEY:
+ case PTR_TO_MAP_VALUE:
+ return true;
+ default:
+ return false;
+ }
+}
+
+/*
+ * _a stands for append, was shortened to avoid multiline statements below.
+ * This macro is used to output a comma separated list of attributes.
+ */
+#define verbose_a(fmt, ...) ({ verbose(env, "%s" fmt, sep, ##__VA_ARGS__); sep = ","; })
+
+static void print_reg_state(struct bpf_verifier_env *env,
+ const struct bpf_func_state *state,
+ const struct bpf_reg_state *reg)
+{
+ enum bpf_reg_type t;
+ const char *sep = "";
+
+ t = reg->type;
+ if (t == SCALAR_VALUE && reg->precise)
+ verbose(env, "P");
+ if (t == SCALAR_VALUE && tnum_is_const(reg->var_off)) {
+ /* reg->off should be 0 for SCALAR_VALUE */
+ verbose_snum(env, reg->var_off.value + reg->off);
+ return;
+ }
+
+ verbose(env, "%s", reg_type_str(env, t));
+ if (t == PTR_TO_STACK) {
+ if (state->frameno != reg->frameno)
+ verbose(env, "[%d]", reg->frameno);
+ if (tnum_is_const(reg->var_off)) {
+ verbose_snum(env, reg->var_off.value + reg->off);
+ return;
+ }
+ }
+ if (base_type(t) == PTR_TO_BTF_ID)
+ verbose(env, "%s", btf_type_name(reg->btf, reg->btf_id));
+ verbose(env, "(");
+ if (reg->id)
+ verbose_a("id=%d", reg->id);
+ if (reg->ref_obj_id)
+ verbose_a("ref_obj_id=%d", reg->ref_obj_id);
+ if (type_is_non_owning_ref(reg->type))
+ verbose_a("%s", "non_own_ref");
+ if (type_is_map_ptr(t)) {
+ if (reg->map_ptr->name[0])
+ verbose_a("map=%s", reg->map_ptr->name);
+ verbose_a("ks=%d,vs=%d",
+ reg->map_ptr->key_size,
+ reg->map_ptr->value_size);
+ }
+ if (t != SCALAR_VALUE && reg->off) {
+ verbose_a("off=");
+ verbose_snum(env, reg->off);
+ }
+ if (type_is_pkt_pointer(t)) {
+ verbose_a("r=");
+ verbose_unum(env, reg->range);
+ }
+ if (base_type(t) == PTR_TO_MEM) {
+ verbose_a("sz=");
+ verbose_unum(env, reg->mem_size);
+ }
+ if (t == CONST_PTR_TO_DYNPTR)
+ verbose_a("type=%s", dynptr_type_str(reg->dynptr.type));
+ if (tnum_is_const(reg->var_off)) {
+ /* a pointer register with fixed offset */
+ if (reg->var_off.value) {
+ verbose_a("imm=");
+ verbose_snum(env, reg->var_off.value);
+ }
+ } else {
+ print_scalar_ranges(env, reg, &sep);
+ if (!tnum_is_unknown(reg->var_off)) {
+ char tn_buf[48];
+
+ tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+ verbose_a("var_off=%s", tn_buf);
+ }
+ }
+ verbose(env, ")");
+}
+
+void print_verifier_state(struct bpf_verifier_env *env, const struct bpf_func_state *state,
+ bool print_all)
+{
+ const struct bpf_reg_state *reg;
+ int i;
+
+ if (state->frameno)
+ verbose(env, " frame%d:", state->frameno);
+ for (i = 0; i < MAX_BPF_REG; i++) {
+ reg = &state->regs[i];
+ if (reg->type == NOT_INIT)
+ continue;
+ if (!print_all && !reg_scratched(env, i))
+ continue;
+ verbose(env, " R%d", i);
+ print_liveness(env, reg->live);
+ verbose(env, "=");
+ print_reg_state(env, state, reg);
+ }
+ for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {
+ char types_buf[BPF_REG_SIZE + 1];
+ const char *sep = "";
+ bool valid = false;
+ u8 slot_type;
+ int j;
+
+ if (!print_all && !stack_slot_scratched(env, i))
+ continue;
+
+ for (j = 0; j < BPF_REG_SIZE; j++) {
+ slot_type = state->stack[i].slot_type[j];
+ if (slot_type != STACK_INVALID)
+ valid = true;
+ types_buf[j] = slot_type_char[slot_type];
+ }
+ types_buf[BPF_REG_SIZE] = 0;
+ if (!valid)
+ continue;
+
+ reg = &state->stack[i].spilled_ptr;
+ switch (state->stack[i].slot_type[BPF_REG_SIZE - 1]) {
+ case STACK_SPILL:
+ /* print MISC/ZERO/INVALID slots above subreg spill */
+ for (j = 0; j < BPF_REG_SIZE; j++)
+ if (state->stack[i].slot_type[j] == STACK_SPILL)
+ break;
+ types_buf[j] = '\0';
+
+ verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
+ print_liveness(env, reg->live);
+ verbose(env, "=%s", types_buf);
+ print_reg_state(env, state, reg);
+ break;
+ case STACK_DYNPTR:
+ /* skip to main dynptr slot */
+ i += BPF_DYNPTR_NR_SLOTS - 1;
+ reg = &state->stack[i].spilled_ptr;
+
+ verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
+ print_liveness(env, reg->live);
+ verbose(env, "=dynptr_%s(", dynptr_type_str(reg->dynptr.type));
+ if (reg->id)
+ verbose_a("id=%d", reg->id);
+ if (reg->ref_obj_id)
+ verbose_a("ref_id=%d", reg->ref_obj_id);
+ if (reg->dynptr_id)
+ verbose_a("dynptr_id=%d", reg->dynptr_id);
+ verbose(env, ")");
+ break;
+ case STACK_ITER:
+ /* only main slot has ref_obj_id set; skip others */
+ if (!reg->ref_obj_id)
+ continue;
+
+ verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
+ print_liveness(env, reg->live);
+ verbose(env, "=iter_%s(ref_id=%d,state=%s,depth=%u)",
+ iter_type_str(reg->iter.btf, reg->iter.btf_id),
+ reg->ref_obj_id, iter_state_str(reg->iter.state),
+ reg->iter.depth);
+ break;
+ case STACK_MISC:
+ case STACK_ZERO:
+ default:
+ verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
+ print_liveness(env, reg->live);
+ verbose(env, "=%s", types_buf);
+ break;
+ }
+ }
+ if (state->acquired_refs && state->refs[0].id) {
+ verbose(env, " refs=%d", state->refs[0].id);
+ for (i = 1; i < state->acquired_refs; i++)
+ if (state->refs[i].id)
+ verbose(env, ",%d", state->refs[i].id);
+ }
+ if (state->in_callback_fn)
+ verbose(env, " cb");
+ if (state->in_async_callback_fn)
+ verbose(env, " async_cb");
+ verbose(env, "\n");
+ if (!print_all)
+ mark_verifier_state_clean(env);
+}
+
+static inline u32 vlog_alignment(u32 pos)
+{
+ return round_up(max(pos + BPF_LOG_MIN_ALIGNMENT / 2, BPF_LOG_ALIGNMENT),
+ BPF_LOG_MIN_ALIGNMENT) - pos - 1;
+}
+
+void print_insn_state(struct bpf_verifier_env *env, const struct bpf_func_state *state)
+{
+ if (env->prev_log_pos && env->prev_log_pos == env->log.end_pos) {
+ /* remove new line character */
+ bpf_vlog_reset(&env->log, env->prev_log_pos - 1);
+ verbose(env, "%*c;", vlog_alignment(env->prev_insn_print_pos), ' ');
+ } else {
+ verbose(env, "%d:", env->insn_idx);
+ }
+ print_verifier_state(env, state, false);
+}
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
index 17c7e7782a1f..b32be680da6c 100644
--- a/kernel/bpf/lpm_trie.c
+++ b/kernel/bpf/lpm_trie.c
@@ -231,6 +231,9 @@ static void *trie_lookup_elem(struct bpf_map *map, void *_key)
struct lpm_trie_node *node, *found = NULL;
struct bpf_lpm_trie_key *key = _key;
+ if (key->prefixlen > trie->max_prefixlen)
+ return NULL;
+
/* Start walking the trie from the root node ... */
for (node = rcu_dereference_check(trie->root, rcu_read_lock_bh_held());
diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c
index cd5eafaba97e..8ef269e66ba5 100644
--- a/kernel/bpf/map_in_map.c
+++ b/kernel/bpf/map_in_map.c
@@ -127,12 +127,21 @@ void *bpf_map_fd_get_ptr(struct bpf_map *map,
return inner_map;
}
-void bpf_map_fd_put_ptr(void *ptr)
+void bpf_map_fd_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
{
- /* ptr->ops->map_free() has to go through one
- * rcu grace period by itself.
+ struct bpf_map *inner_map = ptr;
+
+ /* Defer the freeing of inner map according to the sleepable attribute
+ * of bpf program which owns the outer map, so unnecessary waiting for
+ * RCU tasks trace grace period can be avoided.
*/
- bpf_map_put(ptr);
+ if (need_defer) {
+ if (atomic64_read(&map->sleepable_refcnt))
+ WRITE_ONCE(inner_map->free_after_mult_rcu_gp, true);
+ else
+ WRITE_ONCE(inner_map->free_after_rcu_gp, true);
+ }
+ bpf_map_put(inner_map);
}
u32 bpf_map_fd_sys_lookup_elem(void *ptr)
diff --git a/kernel/bpf/map_in_map.h b/kernel/bpf/map_in_map.h
index bcb7534afb3c..7d61602354de 100644
--- a/kernel/bpf/map_in_map.h
+++ b/kernel/bpf/map_in_map.h
@@ -13,7 +13,7 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd);
void bpf_map_meta_free(struct bpf_map *map_meta);
void *bpf_map_fd_get_ptr(struct bpf_map *map, struct file *map_file,
int ufd);
-void bpf_map_fd_put_ptr(void *ptr);
+void bpf_map_fd_put_ptr(struct bpf_map *map, void *ptr, bool need_defer);
u32 bpf_map_fd_sys_lookup_elem(void *ptr);
#endif
diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c
index 6a51cfe4c2d6..550f02e2cb13 100644
--- a/kernel/bpf/memalloc.c
+++ b/kernel/bpf/memalloc.c
@@ -121,6 +121,8 @@ struct bpf_mem_caches {
struct bpf_mem_cache cache[NUM_CACHES];
};
+static const u16 sizes[NUM_CACHES] = {96, 192, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096};
+
static struct llist_node notrace *__llist_del_first(struct llist_head *head)
{
struct llist_node *entry, *next;
@@ -462,11 +464,17 @@ static void notrace irq_work_raise(struct bpf_mem_cache *c)
* consume ~ 11 Kbyte per cpu.
* Typical case will be between 11K and 116K closer to 11K.
* bpf progs can and should share bpf_mem_cache when possible.
+ *
+ * Percpu allocation is typically rare. To avoid potential unnecessary large
+ * memory consumption, set low_mark = 1 and high_mark = 3, resulting in c->batch = 1.
*/
static void init_refill_work(struct bpf_mem_cache *c)
{
init_irq_work(&c->refill_work, bpf_mem_refill);
- if (c->unit_size <= 256) {
+ if (c->percpu_size) {
+ c->low_watermark = 1;
+ c->high_watermark = 3;
+ } else if (c->unit_size <= 256) {
c->low_watermark = 32;
c->high_watermark = 96;
} else {
@@ -483,32 +491,16 @@ static void init_refill_work(struct bpf_mem_cache *c)
static void prefill_mem_cache(struct bpf_mem_cache *c, int cpu)
{
- /* To avoid consuming memory assume that 1st run of bpf
- * prog won't be doing more than 4 map_update_elem from
- * irq disabled region
- */
- alloc_bulk(c, c->unit_size <= 256 ? 4 : 1, cpu_to_node(cpu), false);
-}
-
-static int check_obj_size(struct bpf_mem_cache *c, unsigned int idx)
-{
- struct llist_node *first;
- unsigned int obj_size;
+ int cnt = 1;
- first = c->free_llist.first;
- if (!first)
- return 0;
-
- if (c->percpu_size)
- obj_size = pcpu_alloc_size(((void **)first)[1]);
- else
- obj_size = ksize(first);
- if (obj_size != c->unit_size) {
- WARN_ONCE(1, "bpf_mem_cache[%u]: percpu %d, unexpected object size %u, expect %u\n",
- idx, c->percpu_size, obj_size, c->unit_size);
- return -EINVAL;
- }
- return 0;
+ /* To avoid consuming memory, for non-percpu allocation, assume that
+ * 1st run of bpf prog won't be doing more than 4 map_update_elem from
+ * irq disabled region if unit size is less than or equal to 256.
+ * For all other cases, let us just do one allocation.
+ */
+ if (!c->percpu_size && c->unit_size <= 256)
+ cnt = 4;
+ alloc_bulk(c, cnt, cpu_to_node(cpu), false);
}
/* When size != 0 bpf_mem_cache for each cpu.
@@ -520,11 +512,13 @@ static int check_obj_size(struct bpf_mem_cache *c, unsigned int idx)
*/
int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu)
{
- static u16 sizes[NUM_CACHES] = {96, 192, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096};
- int cpu, i, err, unit_size, percpu_size = 0;
struct bpf_mem_caches *cc, __percpu *pcc;
struct bpf_mem_cache *c, __percpu *pc;
struct obj_cgroup *objcg = NULL;
+ int cpu, i, unit_size, percpu_size = 0;
+
+ if (percpu && size == 0)
+ return -EINVAL;
/* room for llist_node and per-cpu pointer */
if (percpu)
@@ -544,6 +538,8 @@ int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu)
if (memcg_bpf_enabled())
objcg = get_obj_cgroup_from_current();
#endif
+ ma->objcg = objcg;
+
for_each_possible_cpu(cpu) {
c = per_cpu_ptr(pc, cpu);
c->unit_size = unit_size;
@@ -560,10 +556,10 @@ int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu)
pcc = __alloc_percpu_gfp(sizeof(*cc), 8, GFP_KERNEL);
if (!pcc)
return -ENOMEM;
- err = 0;
#ifdef CONFIG_MEMCG_KMEM
objcg = get_obj_cgroup_from_current();
#endif
+ ma->objcg = objcg;
for_each_possible_cpu(cpu) {
cc = per_cpu_ptr(pcc, cpu);
for (i = 0; i < NUM_CACHES; i++) {
@@ -574,28 +570,62 @@ int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu)
c->tgt = c;
init_refill_work(c);
- /* Another bpf_mem_cache will be used when allocating
- * c->unit_size in bpf_mem_alloc(), so doesn't prefill
- * for the bpf_mem_cache because these free objects will
- * never be used.
- */
- if (i != bpf_mem_cache_idx(c->unit_size))
- continue;
prefill_mem_cache(c, cpu);
- err = check_obj_size(c, i);
- if (err)
- goto out;
}
}
-out:
ma->caches = pcc;
- /* refill_work is either zeroed or initialized, so it is safe to
- * call irq_work_sync().
- */
- if (err)
- bpf_mem_alloc_destroy(ma);
- return err;
+ return 0;
+}
+
+int bpf_mem_alloc_percpu_init(struct bpf_mem_alloc *ma, struct obj_cgroup *objcg)
+{
+ struct bpf_mem_caches __percpu *pcc;
+
+ pcc = __alloc_percpu_gfp(sizeof(struct bpf_mem_caches), 8, GFP_KERNEL);
+ if (!pcc)
+ return -ENOMEM;
+
+ ma->caches = pcc;
+ ma->objcg = objcg;
+ ma->percpu = true;
+ return 0;
+}
+
+int bpf_mem_alloc_percpu_unit_init(struct bpf_mem_alloc *ma, int size)
+{
+ struct bpf_mem_caches *cc, __percpu *pcc;
+ int cpu, i, unit_size, percpu_size;
+ struct obj_cgroup *objcg;
+ struct bpf_mem_cache *c;
+
+ i = bpf_mem_cache_idx(size);
+ if (i < 0)
+ return -EINVAL;
+
+ /* room for llist_node and per-cpu pointer */
+ percpu_size = LLIST_NODE_SZ + sizeof(void *);
+
+ unit_size = sizes[i];
+ objcg = ma->objcg;
+ pcc = ma->caches;
+
+ for_each_possible_cpu(cpu) {
+ cc = per_cpu_ptr(pcc, cpu);
+ c = &cc->cache[i];
+ if (c->unit_size)
+ break;
+
+ c->unit_size = unit_size;
+ c->objcg = objcg;
+ c->percpu_size = percpu_size;
+ c->tgt = c;
+
+ init_refill_work(c);
+ prefill_mem_cache(c, cpu);
+ }
+
+ return 0;
}
static void drain_mem_cache(struct bpf_mem_cache *c)
@@ -729,9 +759,8 @@ void bpf_mem_alloc_destroy(struct bpf_mem_alloc *ma)
rcu_in_progress += atomic_read(&c->call_rcu_ttrace_in_progress);
rcu_in_progress += atomic_read(&c->call_rcu_in_progress);
}
- /* objcg is the same across cpus */
- if (c->objcg)
- obj_cgroup_put(c->objcg);
+ if (ma->objcg)
+ obj_cgroup_put(ma->objcg);
destroy_mem_alloc(ma, rcu_in_progress);
}
if (ma->caches) {
@@ -747,8 +776,8 @@ void bpf_mem_alloc_destroy(struct bpf_mem_alloc *ma)
rcu_in_progress += atomic_read(&c->call_rcu_in_progress);
}
}
- if (c->objcg)
- obj_cgroup_put(c->objcg);
+ if (ma->objcg)
+ obj_cgroup_put(ma->objcg);
destroy_mem_alloc(ma, rcu_in_progress);
}
}
@@ -869,9 +898,11 @@ void notrace *bpf_mem_alloc(struct bpf_mem_alloc *ma, size_t size)
void *ret;
if (!size)
- return ZERO_SIZE_PTR;
+ return NULL;
- idx = bpf_mem_cache_idx(size + LLIST_NODE_SZ);
+ if (!ma->percpu)
+ size += LLIST_NODE_SZ;
+ idx = bpf_mem_cache_idx(size);
if (idx < 0)
return NULL;
@@ -879,26 +910,17 @@ void notrace *bpf_mem_alloc(struct bpf_mem_alloc *ma, size_t size)
return !ret ? NULL : ret + LLIST_NODE_SZ;
}
-static notrace int bpf_mem_free_idx(void *ptr, bool percpu)
-{
- size_t size;
-
- if (percpu)
- size = pcpu_alloc_size(*((void **)ptr));
- else
- size = ksize(ptr - LLIST_NODE_SZ);
- return bpf_mem_cache_idx(size);
-}
-
void notrace bpf_mem_free(struct bpf_mem_alloc *ma, void *ptr)
{
+ struct bpf_mem_cache *c;
int idx;
if (!ptr)
return;
- idx = bpf_mem_free_idx(ptr, ma->percpu);
- if (idx < 0)
+ c = *(void **)(ptr - LLIST_NODE_SZ);
+ idx = bpf_mem_cache_idx(c->unit_size);
+ if (WARN_ON_ONCE(idx < 0))
return;
unit_free(this_cpu_ptr(ma->caches)->cache + idx, ptr);
@@ -906,13 +928,15 @@ void notrace bpf_mem_free(struct bpf_mem_alloc *ma, void *ptr)
void notrace bpf_mem_free_rcu(struct bpf_mem_alloc *ma, void *ptr)
{
+ struct bpf_mem_cache *c;
int idx;
if (!ptr)
return;
- idx = bpf_mem_free_idx(ptr, ma->percpu);
- if (idx < 0)
+ c = *(void **)(ptr - LLIST_NODE_SZ);
+ idx = bpf_mem_cache_idx(c->unit_size);
+ if (WARN_ON_ONCE(idx < 0))
return;
unit_free_rcu(this_cpu_ptr(ma->caches)->cache + idx, ptr);
@@ -986,41 +1010,3 @@ void notrace *bpf_mem_cache_alloc_flags(struct bpf_mem_alloc *ma, gfp_t flags)
return !ret ? NULL : ret + LLIST_NODE_SZ;
}
-
-/* The alignment of dynamic per-cpu area is 8, so c->unit_size and the
- * actual size of dynamic per-cpu area will always be matched and there is
- * no need to adjust size_index for per-cpu allocation. However for the
- * simplicity of the implementation, use an unified size_index for both
- * kmalloc and per-cpu allocation.
- */
-static __init int bpf_mem_cache_adjust_size(void)
-{
- unsigned int size;
-
- /* Adjusting the indexes in size_index() according to the object_size
- * of underlying slab cache, so bpf_mem_alloc() will select a
- * bpf_mem_cache with unit_size equal to the object_size of
- * the underlying slab cache.
- *
- * The maximal value of KMALLOC_MIN_SIZE and __kmalloc_minalign() is
- * 256-bytes, so only do adjustment for [8-bytes, 192-bytes].
- */
- for (size = 192; size >= 8; size -= 8) {
- unsigned int kmalloc_size, index;
-
- kmalloc_size = kmalloc_size_roundup(size);
- if (kmalloc_size == size)
- continue;
-
- if (kmalloc_size <= 192)
- index = size_index[(kmalloc_size - 1) / 8];
- else
- index = fls(kmalloc_size - 1) - 1;
- /* Only overwrite if necessary */
- if (size_index[(size - 1) / 8] != index)
- size_index[(size - 1) / 8] = index;
- }
-
- return 0;
-}
-subsys_initcall(bpf_mem_cache_adjust_size);
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index d6b277482085..dff7ba539701 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -388,6 +388,7 @@ static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task,
{
u32 trace_nr, copy_len, elem_size, num_elem, max_depth;
bool user_build_id = flags & BPF_F_USER_BUILD_ID;
+ bool crosstask = task && task != current;
u32 skip = flags & BPF_F_SKIP_FIELD_MASK;
bool user = flags & BPF_F_USER_STACK;
struct perf_callchain_entry *trace;
@@ -410,6 +411,14 @@ static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task,
if (task && user && !user_mode(regs))
goto err_fault;
+ /* get_perf_callchain does not support crosstask user stack walking
+ * but returns an empty stack instead of NULL.
+ */
+ if (crosstask && user) {
+ err = -EOPNOTSUPP;
+ goto clear;
+ }
+
num_elem = size / elem_size;
max_depth = num_elem + skip;
if (sysctl_perf_event_max_stack < max_depth)
@@ -421,7 +430,7 @@ static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task,
trace = get_callchain_entry_for_task(task, max_depth);
else
trace = get_perf_callchain(regs, 0, kernel, user, max_depth,
- false, false);
+ crosstask, false);
if (unlikely(!trace))
goto err_fault;
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 0ed286b8a0f0..a1f18681721c 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -142,9 +142,13 @@ static u32 bpf_map_value_size(const struct bpf_map *map)
static void maybe_wait_bpf_programs(struct bpf_map *map)
{
- /* Wait for any running BPF programs to complete so that
- * userspace, when we return to it, knows that all programs
- * that could be running use the new map value.
+ /* Wait for any running non-sleepable BPF programs to complete so that
+ * userspace, when we return to it, knows that all non-sleepable
+ * programs that could be running use the new map value. For sleepable
+ * BPF programs, synchronize_rcu_tasks_trace() should be used to wait
+ * for the completions of these programs, but considering the waiting
+ * time can be very long and userspace may think it will hang forever,
+ * so don't handle sleepable BPF programs now.
*/
if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
@@ -180,15 +184,11 @@ static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
err = bpf_percpu_cgroup_storage_update(map, key, value,
flags);
} else if (IS_FD_ARRAY(map)) {
- rcu_read_lock();
err = bpf_fd_array_map_update_elem(map, map_file, key, value,
flags);
- rcu_read_unlock();
} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
- rcu_read_lock();
err = bpf_fd_htab_map_update_elem(map, map_file, key, value,
flags);
- rcu_read_unlock();
} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
/* rcu_read_lock() is not needed */
err = bpf_fd_reuseport_array_update_elem(map, key, value,
@@ -203,7 +203,6 @@ static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
rcu_read_unlock();
}
bpf_enable_instrumentation();
- maybe_wait_bpf_programs(map);
return err;
}
@@ -264,7 +263,6 @@ static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
}
bpf_enable_instrumentation();
- maybe_wait_bpf_programs(map);
return err;
}
@@ -694,6 +692,7 @@ static void bpf_map_free_deferred(struct work_struct *work)
{
struct bpf_map *map = container_of(work, struct bpf_map, work);
struct btf_record *rec = map->record;
+ struct btf *btf = map->btf;
security_bpf_map_free(map);
bpf_map_release_memcg(map);
@@ -709,6 +708,10 @@ static void bpf_map_free_deferred(struct work_struct *work)
* template bpf_map struct used during verification.
*/
btf_record_free(rec);
+ /* Delay freeing of btf for maps, as map_free callback may need
+ * struct_meta info which will be freed with btf_put().
+ */
+ btf_put(btf);
}
static void bpf_map_put_uref(struct bpf_map *map)
@@ -719,6 +722,28 @@ static void bpf_map_put_uref(struct bpf_map *map)
}
}
+static void bpf_map_free_in_work(struct bpf_map *map)
+{
+ INIT_WORK(&map->work, bpf_map_free_deferred);
+ /* Avoid spawning kworkers, since they all might contend
+ * for the same mutex like slab_mutex.
+ */
+ queue_work(system_unbound_wq, &map->work);
+}
+
+static void bpf_map_free_rcu_gp(struct rcu_head *rcu)
+{
+ bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu));
+}
+
+static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu)
+{
+ if (rcu_trace_implies_rcu_gp())
+ bpf_map_free_rcu_gp(rcu);
+ else
+ call_rcu(rcu, bpf_map_free_rcu_gp);
+}
+
/* decrement map refcnt and schedule it for freeing via workqueue
* (underlying map implementation ops->map_free() might sleep)
*/
@@ -727,12 +752,14 @@ void bpf_map_put(struct bpf_map *map)
if (atomic64_dec_and_test(&map->refcnt)) {
/* bpf_map_free_id() must be called first */
bpf_map_free_id(map);
- btf_put(map->btf);
- INIT_WORK(&map->work, bpf_map_free_deferred);
- /* Avoid spawning kworkers, since they all might contend
- * for the same mutex like slab_mutex.
- */
- queue_work(system_unbound_wq, &map->work);
+
+ WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt));
+ if (READ_ONCE(map->free_after_mult_rcu_gp))
+ call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp);
+ else if (READ_ONCE(map->free_after_rcu_gp))
+ call_rcu(&map->rcu, bpf_map_free_rcu_gp);
+ else
+ bpf_map_free_in_work(map);
}
}
EXPORT_SYMBOL_GPL(bpf_map_put);
@@ -1524,6 +1551,8 @@ static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
}
err = bpf_map_update_value(map, f.file, key, value, attr->flags);
+ if (!err)
+ maybe_wait_bpf_programs(map);
kvfree(value);
free_key:
@@ -1579,7 +1608,8 @@ static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr)
err = map->ops->map_delete_elem(map, key);
rcu_read_unlock();
bpf_enable_instrumentation();
- maybe_wait_bpf_programs(map);
+ if (!err)
+ maybe_wait_bpf_programs(map);
out:
kvfree(key);
err_put:
@@ -1676,6 +1706,9 @@ int generic_map_delete_batch(struct bpf_map *map,
if (!max_count)
return 0;
+ if (put_user(0, &uattr->batch.count))
+ return -EFAULT;
+
key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
if (!key)
return -ENOMEM;
@@ -1705,7 +1738,6 @@ int generic_map_delete_batch(struct bpf_map *map,
kvfree(key);
- maybe_wait_bpf_programs(map);
return err;
}
@@ -1733,6 +1765,9 @@ int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
if (!max_count)
return 0;
+ if (put_user(0, &uattr->batch.count))
+ return -EFAULT;
+
key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
if (!key)
return -ENOMEM;
@@ -1763,6 +1798,7 @@ int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
kvfree(value);
kvfree(key);
+
return err;
}
@@ -2573,7 +2609,8 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
BPF_F_SLEEPABLE |
BPF_F_TEST_RND_HI32 |
BPF_F_XDP_HAS_FRAGS |
- BPF_F_XDP_DEV_BOUND_ONLY))
+ BPF_F_XDP_DEV_BOUND_ONLY |
+ BPF_F_TEST_REG_INVARIANTS))
return -EINVAL;
if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
@@ -2701,6 +2738,22 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
goto free_prog_sec;
}
+ /*
+ * Bookkeeping for managing the program attachment chain.
+ *
+ * It might be tempting to set attach_tracing_prog flag at the attachment
+ * time, but this will not prevent from loading bunch of tracing prog
+ * first, then attach them one to another.
+ *
+ * The flag attach_tracing_prog is set for the whole program lifecycle, and
+ * doesn't have to be cleared in bpf_tracing_link_release, since tracing
+ * programs cannot change attachment target.
+ */
+ if (type == BPF_PROG_TYPE_TRACING && dst_prog &&
+ dst_prog->type == BPF_PROG_TYPE_TRACING) {
+ prog->aux->attach_tracing_prog = true;
+ }
+
/* find program type: socket_filter vs tracing_filter */
err = find_prog_type(type, prog);
if (err < 0)
@@ -3134,7 +3187,12 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog,
}
if (tgt_prog_fd) {
- /* For now we only allow new targets for BPF_PROG_TYPE_EXT */
+ /*
+ * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this
+ * part would be changed to implement the same for
+ * BPF_PROG_TYPE_TRACING, do not forget to update the way how
+ * attach_tracing_prog flag is set.
+ */
if (prog->type != BPF_PROG_TYPE_EXT) {
err = -EINVAL;
goto out_put_prog;
@@ -3179,6 +3237,10 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog,
*
* - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
* was detached and is going for re-attachment.
+ *
+ * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
+ * are NULL, then program was already attached and user did not provide
+ * tgt_prog_fd so we have no way to find out or create trampoline
*/
if (!prog->aux->dst_trampoline && !tgt_prog) {
/*
@@ -3192,6 +3254,11 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog,
err = -EINVAL;
goto out_unlock;
}
+ /* We can allow re-attach only if we have valid attach_btf. */
+ if (!prog->aux->attach_btf) {
+ err = -EINVAL;
+ goto out_unlock;
+ }
btf_id = prog->aux->attach_btf_id;
key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
}
@@ -4919,8 +4986,10 @@ static int bpf_map_do_batch(const union bpf_attr *attr,
else
BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
err_put:
- if (has_write)
+ if (has_write) {
+ maybe_wait_bpf_programs(map);
bpf_map_write_active_dec(map);
+ }
fdput(f);
return err;
}
@@ -5322,6 +5391,11 @@ static int bpf_prog_bind_map(union bpf_attr *attr)
goto out_unlock;
}
+ /* The bpf program will not access the bpf map, but for the sake of
+ * simplicity, increase sleepable_refcnt for sleepable program as well.
+ */
+ if (prog->aux->sleepable)
+ atomic64_inc(&map->sleepable_refcnt);
memcpy(used_maps_new, used_maps_old,
sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
used_maps_new[prog->aux->used_map_cnt] = map;
diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
index 26082b97894d..e5c3500443c6 100644
--- a/kernel/bpf/task_iter.c
+++ b/kernel/bpf/task_iter.c
@@ -70,15 +70,13 @@ static struct task_struct *task_group_seq_get_next(struct bpf_iter_seq_task_comm
return NULL;
retry:
- task = next_thread(task);
+ task = __next_thread(task);
+ if (!task)
+ return NULL;
next_tid = __task_pid_nr_ns(task, PIDTYPE_PID, common->ns);
- if (!next_tid || next_tid == common->pid) {
- /* Run out of tasks of a process. The tasks of a
- * thread_group are linked as circular linked list.
- */
- return NULL;
- }
+ if (!next_tid)
+ goto retry;
if (skip_if_dup_files && task->files == task->group_leader->files)
goto retry;
@@ -980,7 +978,6 @@ __bpf_kfunc int bpf_iter_task_new(struct bpf_iter_task *it,
BUILD_BUG_ON(__alignof__(struct bpf_iter_task_kern) !=
__alignof__(struct bpf_iter_task));
- kit->task = kit->pos = NULL;
switch (flags) {
case BPF_TASK_ITER_ALL_THREADS:
case BPF_TASK_ITER_ALL_PROCS:
@@ -1017,20 +1014,16 @@ __bpf_kfunc struct task_struct *bpf_iter_task_next(struct bpf_iter_task *it)
if (flags == BPF_TASK_ITER_ALL_PROCS)
goto get_next_task;
- kit->pos = next_thread(kit->pos);
- if (kit->pos == kit->task) {
- if (flags == BPF_TASK_ITER_PROC_THREADS) {
- kit->pos = NULL;
- return pos;
- }
- } else
+ kit->pos = __next_thread(kit->pos);
+ if (kit->pos || flags == BPF_TASK_ITER_PROC_THREADS)
return pos;
get_next_task:
- kit->pos = next_task(kit->pos);
- kit->task = kit->pos;
- if (kit->pos == &init_task)
+ kit->task = next_task(kit->task);
+ if (kit->task == &init_task)
kit->pos = NULL;
+ else
+ kit->pos = kit->task;
return pos;
}
diff --git a/kernel/bpf/tnum.c b/kernel/bpf/tnum.c
index 3d7127f439a1..9dbc31b25e3d 100644
--- a/kernel/bpf/tnum.c
+++ b/kernel/bpf/tnum.c
@@ -172,12 +172,6 @@ bool tnum_in(struct tnum a, struct tnum b)
return a.value == b.value;
}
-int tnum_strn(char *str, size_t size, struct tnum a)
-{
- return snprintf(str, size, "(%#llx; %#llx)", a.value, a.mask);
-}
-EXPORT_SYMBOL_GPL(tnum_strn);
-
int tnum_sbin(char *str, size_t size, struct tnum a)
{
size_t n;
@@ -208,7 +202,12 @@ struct tnum tnum_clear_subreg(struct tnum a)
return tnum_lshift(tnum_rshift(a, 32), 32);
}
+struct tnum tnum_with_subreg(struct tnum reg, struct tnum subreg)
+{
+ return tnum_or(tnum_clear_subreg(reg), tnum_subreg(subreg));
+}
+
struct tnum tnum_const_subreg(struct tnum a, u32 value)
{
- return tnum_or(tnum_clear_subreg(a), tnum_const(value));
+ return tnum_with_subreg(a, tnum_const(value));
}
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index e97aeda3a86b..d382f5ebe06c 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -115,10 +115,10 @@ bool bpf_prog_has_trampoline(const struct bpf_prog *prog)
(ptype == BPF_PROG_TYPE_LSM && eatype == BPF_LSM_MAC);
}
-void bpf_image_ksym_add(void *data, struct bpf_ksym *ksym)
+void bpf_image_ksym_add(void *data, unsigned int size, struct bpf_ksym *ksym)
{
ksym->start = (unsigned long) data;
- ksym->end = ksym->start + PAGE_SIZE;
+ ksym->end = ksym->start + size;
bpf_ksym_add(ksym);
perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF, ksym->start,
PAGE_SIZE, false, ksym->name);
@@ -254,8 +254,8 @@ bpf_trampoline_get_progs(const struct bpf_trampoline *tr, int *total, bool *ip_a
static void bpf_tramp_image_free(struct bpf_tramp_image *im)
{
bpf_image_ksym_del(&im->ksym);
- bpf_jit_free_exec(im->image);
- bpf_jit_uncharge_modmem(PAGE_SIZE);
+ arch_free_bpf_trampoline(im->image, im->size);
+ bpf_jit_uncharge_modmem(im->size);
percpu_ref_exit(&im->pcref);
kfree_rcu(im, rcu);
}
@@ -349,7 +349,7 @@ static void bpf_tramp_image_put(struct bpf_tramp_image *im)
call_rcu_tasks_trace(&im->rcu, __bpf_tramp_image_put_rcu_tasks);
}
-static struct bpf_tramp_image *bpf_tramp_image_alloc(u64 key)
+static struct bpf_tramp_image *bpf_tramp_image_alloc(u64 key, int size)
{
struct bpf_tramp_image *im;
struct bpf_ksym *ksym;
@@ -360,15 +360,15 @@ static struct bpf_tramp_image *bpf_tramp_image_alloc(u64 key)
if (!im)
goto out;
- err = bpf_jit_charge_modmem(PAGE_SIZE);
+ err = bpf_jit_charge_modmem(size);
if (err)
goto out_free_im;
+ im->size = size;
err = -ENOMEM;
- im->image = image = bpf_jit_alloc_exec(PAGE_SIZE);
+ im->image = image = arch_alloc_bpf_trampoline(size);
if (!image)
goto out_uncharge;
- set_vm_flush_reset_perms(image);
err = percpu_ref_init(&im->pcref, __bpf_tramp_image_release, 0, GFP_KERNEL);
if (err)
@@ -377,13 +377,13 @@ static struct bpf_tramp_image *bpf_tramp_image_alloc(u64 key)
ksym = &im->ksym;
INIT_LIST_HEAD_RCU(&ksym->lnode);
snprintf(ksym->name, KSYM_NAME_LEN, "bpf_trampoline_%llu", key);
- bpf_image_ksym_add(image, ksym);
+ bpf_image_ksym_add(image, size, ksym);
return im;
out_free_image:
- bpf_jit_free_exec(im->image);
+ arch_free_bpf_trampoline(im->image, im->size);
out_uncharge:
- bpf_jit_uncharge_modmem(PAGE_SIZE);
+ bpf_jit_uncharge_modmem(size);
out_free_im:
kfree(im);
out:
@@ -396,7 +396,7 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut
struct bpf_tramp_links *tlinks;
u32 orig_flags = tr->flags;
bool ip_arg = false;
- int err, total;
+ int err, total, size;
tlinks = bpf_trampoline_get_progs(tr, &total, &ip_arg);
if (IS_ERR(tlinks))
@@ -409,12 +409,6 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut
goto out;
}
- im = bpf_tramp_image_alloc(tr->key);
- if (IS_ERR(im)) {
- err = PTR_ERR(im);
- goto out;
- }
-
/* clear all bits except SHARE_IPMODIFY and TAIL_CALL_CTX */
tr->flags &= (BPF_TRAMP_F_SHARE_IPMODIFY | BPF_TRAMP_F_TAIL_CALL_CTX);
@@ -438,13 +432,31 @@ again:
tr->flags |= BPF_TRAMP_F_ORIG_STACK;
#endif
- err = arch_prepare_bpf_trampoline(im, im->image, im->image + PAGE_SIZE,
+ size = arch_bpf_trampoline_size(&tr->func.model, tr->flags,
+ tlinks, tr->func.addr);
+ if (size < 0) {
+ err = size;
+ goto out;
+ }
+
+ if (size > PAGE_SIZE) {
+ err = -E2BIG;
+ goto out;
+ }
+
+ im = bpf_tramp_image_alloc(tr->key, size);
+ if (IS_ERR(im)) {
+ err = PTR_ERR(im);
+ goto out;
+ }
+
+ err = arch_prepare_bpf_trampoline(im, im->image, im->image + size,
&tr->func.model, tr->flags, tlinks,
tr->func.addr);
if (err < 0)
goto out_free;
- set_memory_rox((long)im->image, 1);
+ arch_protect_bpf_trampoline(im->image, im->size);
WARN_ON(tr->cur_image && total == 0);
if (tr->cur_image)
@@ -464,9 +476,8 @@ again:
tr->fops->func = NULL;
tr->fops->trampoline = 0;
- /* reset im->image memory attr for arch_prepare_bpf_trampoline */
- set_memory_nx((long)im->image, 1);
- set_memory_rw((long)im->image, 1);
+ /* free im memory and reallocate later */
+ bpf_tramp_image_free(im);
goto again;
}
#endif
@@ -1032,10 +1043,50 @@ bpf_trampoline_exit_t bpf_trampoline_exit(const struct bpf_prog *prog)
}
int __weak
-arch_prepare_bpf_trampoline(struct bpf_tramp_image *tr, void *image, void *image_end,
+arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *image_end,
const struct btf_func_model *m, u32 flags,
struct bpf_tramp_links *tlinks,
- void *orig_call)
+ void *func_addr)
+{
+ return -ENOTSUPP;
+}
+
+void * __weak arch_alloc_bpf_trampoline(unsigned int size)
+{
+ void *image;
+
+ if (WARN_ON_ONCE(size > PAGE_SIZE))
+ return NULL;
+ image = bpf_jit_alloc_exec(PAGE_SIZE);
+ if (image)
+ set_vm_flush_reset_perms(image);
+ return image;
+}
+
+void __weak arch_free_bpf_trampoline(void *image, unsigned int size)
+{
+ WARN_ON_ONCE(size > PAGE_SIZE);
+ /* bpf_jit_free_exec doesn't need "size", but
+ * bpf_prog_pack_free() needs it.
+ */
+ bpf_jit_free_exec(image);
+}
+
+void __weak arch_protect_bpf_trampoline(void *image, unsigned int size)
+{
+ WARN_ON_ONCE(size > PAGE_SIZE);
+ set_memory_rox((long)image, 1);
+}
+
+void __weak arch_unprotect_bpf_trampoline(void *image, unsigned int size)
+{
+ WARN_ON_ONCE(size > PAGE_SIZE);
+ set_memory_nx((long)image, 1);
+ set_memory_rw((long)image, 1);
+}
+
+int __weak arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,
+ struct bpf_tramp_links *tlinks, void *func_addr)
{
return -ENOTSUPP;
}
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index af2819d5c8ee..adbf330d364b 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -195,6 +195,8 @@ struct bpf_verifier_stack_elem {
POISON_POINTER_DELTA))
#define BPF_MAP_PTR(X) ((struct bpf_map *)((X) & ~BPF_MAP_PTR_UNPRIV))
+#define BPF_GLOBAL_PERCPU_MA_MAX_SIZE 512
+
static int acquire_reference_state(struct bpf_verifier_env *env, int insn_idx);
static int release_reference(struct bpf_verifier_env *env, int ref_obj_id);
static void invalidate_non_owning_refs(struct bpf_verifier_env *env);
@@ -339,30 +341,14 @@ struct bpf_kfunc_call_arg_meta {
struct btf *btf_vmlinux;
-static DEFINE_MUTEX(bpf_verifier_lock);
-static DEFINE_MUTEX(bpf_percpu_ma_lock);
-
-static const struct bpf_line_info *
-find_linfo(const struct bpf_verifier_env *env, u32 insn_off)
+static const char *btf_type_name(const struct btf *btf, u32 id)
{
- const struct bpf_line_info *linfo;
- const struct bpf_prog *prog;
- u32 i, nr_linfo;
-
- prog = env->prog;
- nr_linfo = prog->aux->nr_linfo;
-
- if (!nr_linfo || insn_off >= prog->len)
- return NULL;
-
- linfo = prog->aux->linfo;
- for (i = 1; i < nr_linfo; i++)
- if (insn_off < linfo[i].insn_off)
- break;
-
- return &linfo[i - 1];
+ return btf_name_by_offset(btf, btf_type_by_id(btf, id)->name_off);
}
+static DEFINE_MUTEX(bpf_verifier_lock);
+static DEFINE_MUTEX(bpf_percpu_ma_lock);
+
__printf(2, 3) static void verbose(void *private_data, const char *fmt, ...)
{
struct bpf_verifier_env *env = private_data;
@@ -376,73 +362,25 @@ __printf(2, 3) static void verbose(void *private_data, const char *fmt, ...)
va_end(args);
}
-static const char *ltrim(const char *s)
-{
- while (isspace(*s))
- s++;
-
- return s;
-}
-
-__printf(3, 4) static void verbose_linfo(struct bpf_verifier_env *env,
- u32 insn_off,
- const char *prefix_fmt, ...)
-{
- const struct bpf_line_info *linfo;
-
- if (!bpf_verifier_log_needed(&env->log))
- return;
-
- linfo = find_linfo(env, insn_off);
- if (!linfo || linfo == env->prev_linfo)
- return;
-
- if (prefix_fmt) {
- va_list args;
-
- va_start(args, prefix_fmt);
- bpf_verifier_vlog(&env->log, prefix_fmt, args);
- va_end(args);
- }
-
- verbose(env, "%s\n",
- ltrim(btf_name_by_offset(env->prog->aux->btf,
- linfo->line_off)));
-
- env->prev_linfo = linfo;
-}
-
static void verbose_invalid_scalar(struct bpf_verifier_env *env,
struct bpf_reg_state *reg,
- struct tnum *range, const char *ctx,
+ struct bpf_retval_range range, const char *ctx,
const char *reg_name)
{
- char tn_buf[48];
+ bool unknown = true;
- verbose(env, "At %s the register %s ", ctx, reg_name);
- if (!tnum_is_unknown(reg->var_off)) {
- tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
- verbose(env, "has value %s", tn_buf);
- } else {
- verbose(env, "has unknown scalar value");
+ verbose(env, "%s the register %s has", ctx, reg_name);
+ if (reg->smin_value > S64_MIN) {
+ verbose(env, " smin=%lld", reg->smin_value);
+ unknown = false;
}
- tnum_strn(tn_buf, sizeof(tn_buf), *range);
- verbose(env, " should have been in %s\n", tn_buf);
-}
-
-static bool type_is_pkt_pointer(enum bpf_reg_type type)
-{
- type = base_type(type);
- return type == PTR_TO_PACKET ||
- type == PTR_TO_PACKET_META;
-}
-
-static bool type_is_sk_pointer(enum bpf_reg_type type)
-{
- return type == PTR_TO_SOCKET ||
- type == PTR_TO_SOCK_COMMON ||
- type == PTR_TO_TCP_SOCK ||
- type == PTR_TO_XDP_SOCK;
+ if (reg->smax_value < S64_MAX) {
+ verbose(env, " smax=%lld", reg->smax_value);
+ unknown = false;
+ }
+ if (unknown)
+ verbose(env, " unknown scalar value");
+ verbose(env, " should have been in [%d, %d]\n", range.minval, range.maxval);
}
static bool type_may_be_null(u32 type)
@@ -468,16 +406,6 @@ static bool reg_not_null(const struct bpf_reg_state *reg)
type == PTR_TO_MEM;
}
-static bool type_is_ptr_alloc_obj(u32 type)
-{
- return base_type(type) == PTR_TO_BTF_ID && type_flag(type) & MEM_ALLOC;
-}
-
-static bool type_is_non_owning_ref(u32 type)
-{
- return type_is_ptr_alloc_obj(type) && type_flag(type) & NON_OWN_REF;
-}
-
static struct btf_record *reg_btf_record(const struct bpf_reg_state *reg)
{
struct btf_record *rec = NULL;
@@ -500,6 +428,31 @@ static bool subprog_is_global(const struct bpf_verifier_env *env, int subprog)
return aux && aux[subprog].linkage == BTF_FUNC_GLOBAL;
}
+static const char *subprog_name(const struct bpf_verifier_env *env, int subprog)
+{
+ struct bpf_func_info *info;
+
+ if (!env->prog->aux->func_info)
+ return "";
+
+ info = &env->prog->aux->func_info[subprog];
+ return btf_type_name(env->prog->aux->btf, info->type_id);
+}
+
+static void mark_subprog_exc_cb(struct bpf_verifier_env *env, int subprog)
+{
+ struct bpf_subprog_info *info = subprog_info(env, subprog);
+
+ info->is_cb = true;
+ info->is_async_cb = true;
+ info->is_exception_cb = true;
+}
+
+static bool subprog_is_exc_cb(struct bpf_verifier_env *env, int subprog)
+{
+ return subprog_info(env, subprog)->is_exception_cb;
+}
+
static bool reg_may_point_to_spin_lock(const struct bpf_reg_state *reg)
{
return btf_record_has_field(reg_btf_record(reg), BPF_SPIN_LOCK);
@@ -605,83 +558,6 @@ static bool is_cmpxchg_insn(const struct bpf_insn *insn)
insn->imm == BPF_CMPXCHG;
}
-/* string representation of 'enum bpf_reg_type'
- *
- * Note that reg_type_str() can not appear more than once in a single verbose()
- * statement.
- */
-static const char *reg_type_str(struct bpf_verifier_env *env,
- enum bpf_reg_type type)
-{
- char postfix[16] = {0}, prefix[64] = {0};
- static const char * const str[] = {
- [NOT_INIT] = "?",
- [SCALAR_VALUE] = "scalar",
- [PTR_TO_CTX] = "ctx",
- [CONST_PTR_TO_MAP] = "map_ptr",
- [PTR_TO_MAP_VALUE] = "map_value",
- [PTR_TO_STACK] = "fp",
- [PTR_TO_PACKET] = "pkt",
- [PTR_TO_PACKET_META] = "pkt_meta",
- [PTR_TO_PACKET_END] = "pkt_end",
- [PTR_TO_FLOW_KEYS] = "flow_keys",
- [PTR_TO_SOCKET] = "sock",
- [PTR_TO_SOCK_COMMON] = "sock_common",
- [PTR_TO_TCP_SOCK] = "tcp_sock",
- [PTR_TO_TP_BUFFER] = "tp_buffer",
- [PTR_TO_XDP_SOCK] = "xdp_sock",
- [PTR_TO_BTF_ID] = "ptr_",
- [PTR_TO_MEM] = "mem",
- [PTR_TO_BUF] = "buf",
- [PTR_TO_FUNC] = "func",
- [PTR_TO_MAP_KEY] = "map_key",
- [CONST_PTR_TO_DYNPTR] = "dynptr_ptr",
- };
-
- if (type & PTR_MAYBE_NULL) {
- if (base_type(type) == PTR_TO_BTF_ID)
- strncpy(postfix, "or_null_", 16);
- else
- strncpy(postfix, "_or_null", 16);
- }
-
- snprintf(prefix, sizeof(prefix), "%s%s%s%s%s%s%s",
- type & MEM_RDONLY ? "rdonly_" : "",
- type & MEM_RINGBUF ? "ringbuf_" : "",
- type & MEM_USER ? "user_" : "",
- type & MEM_PERCPU ? "percpu_" : "",
- type & MEM_RCU ? "rcu_" : "",
- type & PTR_UNTRUSTED ? "untrusted_" : "",
- type & PTR_TRUSTED ? "trusted_" : ""
- );
-
- snprintf(env->tmp_str_buf, TMP_STR_BUF_LEN, "%s%s%s",
- prefix, str[base_type(type)], postfix);
- return env->tmp_str_buf;
-}
-
-static char slot_type_char[] = {
- [STACK_INVALID] = '?',
- [STACK_SPILL] = 'r',
- [STACK_MISC] = 'm',
- [STACK_ZERO] = '0',
- [STACK_DYNPTR] = 'd',
- [STACK_ITER] = 'i',
-};
-
-static void print_liveness(struct bpf_verifier_env *env,
- enum bpf_reg_liveness live)
-{
- if (live & (REG_LIVE_READ | REG_LIVE_WRITTEN | REG_LIVE_DONE))
- verbose(env, "_");
- if (live & REG_LIVE_READ)
- verbose(env, "r");
- if (live & REG_LIVE_WRITTEN)
- verbose(env, "w");
- if (live & REG_LIVE_DONE)
- verbose(env, "D");
-}
-
static int __get_spi(s32 off)
{
return (-off - 1) / BPF_REG_SIZE;
@@ -746,92 +622,6 @@ static int iter_get_spi(struct bpf_verifier_env *env, struct bpf_reg_state *reg,
return stack_slot_obj_get_spi(env, reg, "iter", nr_slots);
}
-static const char *btf_type_name(const struct btf *btf, u32 id)
-{
- return btf_name_by_offset(btf, btf_type_by_id(btf, id)->name_off);
-}
-
-static const char *dynptr_type_str(enum bpf_dynptr_type type)
-{
- switch (type) {
- case BPF_DYNPTR_TYPE_LOCAL:
- return "local";
- case BPF_DYNPTR_TYPE_RINGBUF:
- return "ringbuf";
- case BPF_DYNPTR_TYPE_SKB:
- return "skb";
- case BPF_DYNPTR_TYPE_XDP:
- return "xdp";
- case BPF_DYNPTR_TYPE_INVALID:
- return "<invalid>";
- default:
- WARN_ONCE(1, "unknown dynptr type %d\n", type);
- return "<unknown>";
- }
-}
-
-static const char *iter_type_str(const struct btf *btf, u32 btf_id)
-{
- if (!btf || btf_id == 0)
- return "<invalid>";
-
- /* we already validated that type is valid and has conforming name */
- return btf_type_name(btf, btf_id) + sizeof(ITER_PREFIX) - 1;
-}
-
-static const char *iter_state_str(enum bpf_iter_state state)
-{
- switch (state) {
- case BPF_ITER_STATE_ACTIVE:
- return "active";
- case BPF_ITER_STATE_DRAINED:
- return "drained";
- case BPF_ITER_STATE_INVALID:
- return "<invalid>";
- default:
- WARN_ONCE(1, "unknown iter state %d\n", state);
- return "<unknown>";
- }
-}
-
-static void mark_reg_scratched(struct bpf_verifier_env *env, u32 regno)
-{
- env->scratched_regs |= 1U << regno;
-}
-
-static void mark_stack_slot_scratched(struct bpf_verifier_env *env, u32 spi)
-{
- env->scratched_stack_slots |= 1ULL << spi;
-}
-
-static bool reg_scratched(const struct bpf_verifier_env *env, u32 regno)
-{
- return (env->scratched_regs >> regno) & 1;
-}
-
-static bool stack_slot_scratched(const struct bpf_verifier_env *env, u64 regno)
-{
- return (env->scratched_stack_slots >> regno) & 1;
-}
-
-static bool verifier_state_scratched(const struct bpf_verifier_env *env)
-{
- return env->scratched_regs || env->scratched_stack_slots;
-}
-
-static void mark_verifier_state_clean(struct bpf_verifier_env *env)
-{
- env->scratched_regs = 0U;
- env->scratched_stack_slots = 0ULL;
-}
-
-/* Used for printing the entire verifier state. */
-static void mark_verifier_state_scratched(struct bpf_verifier_env *env)
-{
- env->scratched_regs = ~0U;
- env->scratched_stack_slots = ~0ULL;
-}
-
static enum bpf_dynptr_type arg_to_dynptr_type(enum bpf_arg_type arg_type)
{
switch (arg_type & DYNPTR_TYPE_FLAG_MASK) {
@@ -1365,230 +1155,25 @@ static bool is_spilled_scalar_reg(const struct bpf_stack_state *stack)
stack->spilled_ptr.type == SCALAR_VALUE;
}
-static void scrub_spilled_slot(u8 *stype)
-{
- if (*stype != STACK_INVALID)
- *stype = STACK_MISC;
-}
-
-static void print_scalar_ranges(struct bpf_verifier_env *env,
- const struct bpf_reg_state *reg,
- const char **sep)
-{
- struct {
- const char *name;
- u64 val;
- bool omit;
- } minmaxs[] = {
- {"smin", reg->smin_value, reg->smin_value == S64_MIN},
- {"smax", reg->smax_value, reg->smax_value == S64_MAX},
- {"umin", reg->umin_value, reg->umin_value == 0},
- {"umax", reg->umax_value, reg->umax_value == U64_MAX},
- {"smin32", (s64)reg->s32_min_value, reg->s32_min_value == S32_MIN},
- {"smax32", (s64)reg->s32_max_value, reg->s32_max_value == S32_MAX},
- {"umin32", reg->u32_min_value, reg->u32_min_value == 0},
- {"umax32", reg->u32_max_value, reg->u32_max_value == U32_MAX},
- }, *m1, *m2, *mend = &minmaxs[ARRAY_SIZE(minmaxs)];
- bool neg1, neg2;
-
- for (m1 = &minmaxs[0]; m1 < mend; m1++) {
- if (m1->omit)
- continue;
-
- neg1 = m1->name[0] == 's' && (s64)m1->val < 0;
-
- verbose(env, "%s%s=", *sep, m1->name);
- *sep = ",";
-
- for (m2 = m1 + 2; m2 < mend; m2 += 2) {
- if (m2->omit || m2->val != m1->val)
- continue;
- /* don't mix negatives with positives */
- neg2 = m2->name[0] == 's' && (s64)m2->val < 0;
- if (neg2 != neg1)
- continue;
- m2->omit = true;
- verbose(env, "%s=", m2->name);
- }
-
- verbose(env, m1->name[0] == 's' ? "%lld" : "%llu", m1->val);
- }
-}
-
-static void print_verifier_state(struct bpf_verifier_env *env,
- const struct bpf_func_state *state,
- bool print_all)
-{
- const struct bpf_reg_state *reg;
- enum bpf_reg_type t;
- int i;
-
- if (state->frameno)
- verbose(env, " frame%d:", state->frameno);
- for (i = 0; i < MAX_BPF_REG; i++) {
- reg = &state->regs[i];
- t = reg->type;
- if (t == NOT_INIT)
- continue;
- if (!print_all && !reg_scratched(env, i))
- continue;
- verbose(env, " R%d", i);
- print_liveness(env, reg->live);
- verbose(env, "=");
- if (t == SCALAR_VALUE && reg->precise)
- verbose(env, "P");
- if ((t == SCALAR_VALUE || t == PTR_TO_STACK) &&
- tnum_is_const(reg->var_off)) {
- /* reg->off should be 0 for SCALAR_VALUE */
- verbose(env, "%s", t == SCALAR_VALUE ? "" : reg_type_str(env, t));
- verbose(env, "%lld", reg->var_off.value + reg->off);
- } else {
- const char *sep = "";
-
- verbose(env, "%s", reg_type_str(env, t));
- if (base_type(t) == PTR_TO_BTF_ID)
- verbose(env, "%s", btf_type_name(reg->btf, reg->btf_id));
- verbose(env, "(");
-/*
- * _a stands for append, was shortened to avoid multiline statements below.
- * This macro is used to output a comma separated list of attributes.
+/* Mark stack slot as STACK_MISC, unless it is already STACK_INVALID, in which
+ * case they are equivalent, or it's STACK_ZERO, in which case we preserve
+ * more precise STACK_ZERO.
+ * Note, in uprivileged mode leaving STACK_INVALID is wrong, so we take
+ * env->allow_ptr_leaks into account and force STACK_MISC, if necessary.
*/
-#define verbose_a(fmt, ...) ({ verbose(env, "%s" fmt, sep, __VA_ARGS__); sep = ","; })
-
- if (reg->id)
- verbose_a("id=%d", reg->id);
- if (reg->ref_obj_id)
- verbose_a("ref_obj_id=%d", reg->ref_obj_id);
- if (type_is_non_owning_ref(reg->type))
- verbose_a("%s", "non_own_ref");
- if (t != SCALAR_VALUE)
- verbose_a("off=%d", reg->off);
- if (type_is_pkt_pointer(t))
- verbose_a("r=%d", reg->range);
- else if (base_type(t) == CONST_PTR_TO_MAP ||
- base_type(t) == PTR_TO_MAP_KEY ||
- base_type(t) == PTR_TO_MAP_VALUE)
- verbose_a("ks=%d,vs=%d",
- reg->map_ptr->key_size,
- reg->map_ptr->value_size);
- if (tnum_is_const(reg->var_off)) {
- /* Typically an immediate SCALAR_VALUE, but
- * could be a pointer whose offset is too big
- * for reg->off
- */
- verbose_a("imm=%llx", reg->var_off.value);
- } else {
- print_scalar_ranges(env, reg, &sep);
- if (!tnum_is_unknown(reg->var_off)) {
- char tn_buf[48];
-
- tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
- verbose_a("var_off=%s", tn_buf);
- }
- }
-#undef verbose_a
-
- verbose(env, ")");
- }
- }
- for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {
- char types_buf[BPF_REG_SIZE + 1];
- bool valid = false;
- int j;
-
- for (j = 0; j < BPF_REG_SIZE; j++) {
- if (state->stack[i].slot_type[j] != STACK_INVALID)
- valid = true;
- types_buf[j] = slot_type_char[state->stack[i].slot_type[j]];
- }
- types_buf[BPF_REG_SIZE] = 0;
- if (!valid)
- continue;
- if (!print_all && !stack_slot_scratched(env, i))
- continue;
- switch (state->stack[i].slot_type[BPF_REG_SIZE - 1]) {
- case STACK_SPILL:
- reg = &state->stack[i].spilled_ptr;
- t = reg->type;
-
- verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
- print_liveness(env, reg->live);
- verbose(env, "=%s", t == SCALAR_VALUE ? "" : reg_type_str(env, t));
- if (t == SCALAR_VALUE && reg->precise)
- verbose(env, "P");
- if (t == SCALAR_VALUE && tnum_is_const(reg->var_off))
- verbose(env, "%lld", reg->var_off.value + reg->off);
- break;
- case STACK_DYNPTR:
- i += BPF_DYNPTR_NR_SLOTS - 1;
- reg = &state->stack[i].spilled_ptr;
-
- verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
- print_liveness(env, reg->live);
- verbose(env, "=dynptr_%s", dynptr_type_str(reg->dynptr.type));
- if (reg->ref_obj_id)
- verbose(env, "(ref_id=%d)", reg->ref_obj_id);
- break;
- case STACK_ITER:
- /* only main slot has ref_obj_id set; skip others */
- reg = &state->stack[i].spilled_ptr;
- if (!reg->ref_obj_id)
- continue;
-
- verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
- print_liveness(env, reg->live);
- verbose(env, "=iter_%s(ref_id=%d,state=%s,depth=%u)",
- iter_type_str(reg->iter.btf, reg->iter.btf_id),
- reg->ref_obj_id, iter_state_str(reg->iter.state),
- reg->iter.depth);
- break;
- case STACK_MISC:
- case STACK_ZERO:
- default:
- reg = &state->stack[i].spilled_ptr;
-
- for (j = 0; j < BPF_REG_SIZE; j++)
- types_buf[j] = slot_type_char[state->stack[i].slot_type[j]];
- types_buf[BPF_REG_SIZE] = 0;
-
- verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
- print_liveness(env, reg->live);
- verbose(env, "=%s", types_buf);
- break;
- }
- }
- if (state->acquired_refs && state->refs[0].id) {
- verbose(env, " refs=%d", state->refs[0].id);
- for (i = 1; i < state->acquired_refs; i++)
- if (state->refs[i].id)
- verbose(env, ",%d", state->refs[i].id);
- }
- if (state->in_callback_fn)
- verbose(env, " cb");
- if (state->in_async_callback_fn)
- verbose(env, " async_cb");
- verbose(env, "\n");
- if (!print_all)
- mark_verifier_state_clean(env);
-}
-
-static inline u32 vlog_alignment(u32 pos)
+static void mark_stack_slot_misc(struct bpf_verifier_env *env, u8 *stype)
{
- return round_up(max(pos + BPF_LOG_MIN_ALIGNMENT / 2, BPF_LOG_ALIGNMENT),
- BPF_LOG_MIN_ALIGNMENT) - pos - 1;
+ if (*stype == STACK_ZERO)
+ return;
+ if (env->allow_ptr_leaks && *stype == STACK_INVALID)
+ return;
+ *stype = STACK_MISC;
}
-static void print_insn_state(struct bpf_verifier_env *env,
- const struct bpf_func_state *state)
+static void scrub_spilled_slot(u8 *stype)
{
- if (env->prev_log_pos && env->prev_log_pos == env->log.end_pos) {
- /* remove new line character */
- bpf_vlog_reset(&env->log, env->prev_log_pos - 1);
- verbose(env, "%*c;", vlog_alignment(env->prev_insn_print_pos), ' ');
- } else {
- verbose(env, "%d:", env->insn_idx);
- }
- print_verifier_state(env, state, false);
+ if (*stype != STACK_INVALID)
+ *stype = STACK_MISC;
}
/* copy array src of length n * size bytes to dst. dst is reallocated if it's too
@@ -1685,9 +1270,16 @@ static int resize_reference_state(struct bpf_func_state *state, size_t n)
return 0;
}
-static int grow_stack_state(struct bpf_func_state *state, int size)
+/* Possibly update state->allocated_stack to be at least size bytes. Also
+ * possibly update the function's high-water mark in its bpf_subprog_info.
+ */
+static int grow_stack_state(struct bpf_verifier_env *env, struct bpf_func_state *state, int size)
{
- size_t old_n = state->allocated_stack / BPF_REG_SIZE, n = size / BPF_REG_SIZE;
+ size_t old_n = state->allocated_stack / BPF_REG_SIZE, n;
+
+ /* The stack size is always a multiple of BPF_REG_SIZE. */
+ size = round_up(size, BPF_REG_SIZE);
+ n = size / BPF_REG_SIZE;
if (old_n >= n)
return 0;
@@ -1697,6 +1289,11 @@ static int grow_stack_state(struct bpf_func_state *state, int size)
return -ENOMEM;
state->allocated_stack = size;
+
+ /* update known max for given subprogram */
+ if (env->subprog_info[state->subprogno].stack_depth < size)
+ env->subprog_info[state->subprogno].stack_depth = size;
+
return 0;
}
@@ -1796,8 +1393,8 @@ static int copy_verifier_state(struct bpf_verifier_state *dst_state,
int i, err;
dst_state->jmp_history = copy_array(dst_state->jmp_history, src->jmp_history,
- src->jmp_history_cnt, sizeof(struct bpf_idx_pair),
- GFP_USER);
+ src->jmp_history_cnt, sizeof(*dst_state->jmp_history),
+ GFP_USER);
if (!dst_state->jmp_history)
return -ENOMEM;
dst_state->jmp_history_cnt = src->jmp_history_cnt;
@@ -2172,10 +1769,14 @@ static void __mark_reg_known_zero(struct bpf_reg_state *reg)
__mark_reg_known(reg, 0);
}
-static void __mark_reg_const_zero(struct bpf_reg_state *reg)
+static void __mark_reg_const_zero(const struct bpf_verifier_env *env, struct bpf_reg_state *reg)
{
__mark_reg_known(reg, 0);
reg->type = SCALAR_VALUE;
+ /* all scalars are assumed imprecise initially (unless unprivileged,
+ * in which case everything is forced to be precise)
+ */
+ reg->precise = !env->bpf_capable;
}
static void mark_reg_known_zero(struct bpf_verifier_env *env,
@@ -2341,69 +1942,214 @@ static void __update_reg_bounds(struct bpf_reg_state *reg)
/* Uses signed min/max values to inform unsigned, and vice-versa */
static void __reg32_deduce_bounds(struct bpf_reg_state *reg)
{
- /* Learn sign from signed bounds.
- * If we cannot cross the sign boundary, then signed and unsigned bounds
- * are the same, so combine. This works even in the negative case, e.g.
- * -3 s<= x s<= -1 implies 0xf...fd u<= x u<= 0xf...ff.
+ /* If upper 32 bits of u64/s64 range don't change, we can use lower 32
+ * bits to improve our u32/s32 boundaries.
+ *
+ * E.g., the case where we have upper 32 bits as zero ([10, 20] in
+ * u64) is pretty trivial, it's obvious that in u32 we'll also have
+ * [10, 20] range. But this property holds for any 64-bit range as
+ * long as upper 32 bits in that entire range of values stay the same.
+ *
+ * E.g., u64 range [0x10000000A, 0x10000000F] ([4294967306, 4294967311]
+ * in decimal) has the same upper 32 bits throughout all the values in
+ * that range. As such, lower 32 bits form a valid [0xA, 0xF] ([10, 15])
+ * range.
+ *
+ * Note also, that [0xA, 0xF] is a valid range both in u32 and in s32,
+ * following the rules outlined below about u64/s64 correspondence
+ * (which equally applies to u32 vs s32 correspondence). In general it
+ * depends on actual hexadecimal values of 32-bit range. They can form
+ * only valid u32, or only valid s32 ranges in some cases.
+ *
+ * So we use all these insights to derive bounds for subregisters here.
*/
- if (reg->s32_min_value >= 0 || reg->s32_max_value < 0) {
- reg->s32_min_value = reg->u32_min_value =
- max_t(u32, reg->s32_min_value, reg->u32_min_value);
- reg->s32_max_value = reg->u32_max_value =
- min_t(u32, reg->s32_max_value, reg->u32_max_value);
- return;
+ if ((reg->umin_value >> 32) == (reg->umax_value >> 32)) {
+ /* u64 to u32 casting preserves validity of low 32 bits as
+ * a range, if upper 32 bits are the same
+ */
+ reg->u32_min_value = max_t(u32, reg->u32_min_value, (u32)reg->umin_value);
+ reg->u32_max_value = min_t(u32, reg->u32_max_value, (u32)reg->umax_value);
+
+ if ((s32)reg->umin_value <= (s32)reg->umax_value) {
+ reg->s32_min_value = max_t(s32, reg->s32_min_value, (s32)reg->umin_value);
+ reg->s32_max_value = min_t(s32, reg->s32_max_value, (s32)reg->umax_value);
+ }
+ }
+ if ((reg->smin_value >> 32) == (reg->smax_value >> 32)) {
+ /* low 32 bits should form a proper u32 range */
+ if ((u32)reg->smin_value <= (u32)reg->smax_value) {
+ reg->u32_min_value = max_t(u32, reg->u32_min_value, (u32)reg->smin_value);
+ reg->u32_max_value = min_t(u32, reg->u32_max_value, (u32)reg->smax_value);
+ }
+ /* low 32 bits should form a proper s32 range */
+ if ((s32)reg->smin_value <= (s32)reg->smax_value) {
+ reg->s32_min_value = max_t(s32, reg->s32_min_value, (s32)reg->smin_value);
+ reg->s32_max_value = min_t(s32, reg->s32_max_value, (s32)reg->smax_value);
+ }
+ }
+ /* Special case where upper bits form a small sequence of two
+ * sequential numbers (in 32-bit unsigned space, so 0xffffffff to
+ * 0x00000000 is also valid), while lower bits form a proper s32 range
+ * going from negative numbers to positive numbers. E.g., let's say we
+ * have s64 range [-1, 1] ([0xffffffffffffffff, 0x0000000000000001]).
+ * Possible s64 values are {-1, 0, 1} ({0xffffffffffffffff,
+ * 0x0000000000000000, 0x00000000000001}). Ignoring upper 32 bits,
+ * we still get a valid s32 range [-1, 1] ([0xffffffff, 0x00000001]).
+ * Note that it doesn't have to be 0xffffffff going to 0x00000000 in
+ * upper 32 bits. As a random example, s64 range
+ * [0xfffffff0fffffff0; 0xfffffff100000010], forms a valid s32 range
+ * [-16, 16] ([0xfffffff0; 0x00000010]) in its 32 bit subregister.
+ */
+ if ((u32)(reg->umin_value >> 32) + 1 == (u32)(reg->umax_value >> 32) &&
+ (s32)reg->umin_value < 0 && (s32)reg->umax_value >= 0) {
+ reg->s32_min_value = max_t(s32, reg->s32_min_value, (s32)reg->umin_value);
+ reg->s32_max_value = min_t(s32, reg->s32_max_value, (s32)reg->umax_value);
+ }
+ if ((u32)(reg->smin_value >> 32) + 1 == (u32)(reg->smax_value >> 32) &&
+ (s32)reg->smin_value < 0 && (s32)reg->smax_value >= 0) {
+ reg->s32_min_value = max_t(s32, reg->s32_min_value, (s32)reg->smin_value);
+ reg->s32_max_value = min_t(s32, reg->s32_max_value, (s32)reg->smax_value);
+ }
+ /* if u32 range forms a valid s32 range (due to matching sign bit),
+ * try to learn from that
+ */
+ if ((s32)reg->u32_min_value <= (s32)reg->u32_max_value) {
+ reg->s32_min_value = max_t(s32, reg->s32_min_value, reg->u32_min_value);
+ reg->s32_max_value = min_t(s32, reg->s32_max_value, reg->u32_max_value);
}
- /* Learn sign from unsigned bounds. Signed bounds cross the sign
- * boundary, so we must be careful.
+ /* If we cannot cross the sign boundary, then signed and unsigned bounds
+ * are the same, so combine. This works even in the negative case, e.g.
+ * -3 s<= x s<= -1 implies 0xf...fd u<= x u<= 0xf...ff.
*/
- if ((s32)reg->u32_max_value >= 0) {
- /* Positive. We can't learn anything from the smin, but smax
- * is positive, hence safe.
- */
- reg->s32_min_value = reg->u32_min_value;
- reg->s32_max_value = reg->u32_max_value =
- min_t(u32, reg->s32_max_value, reg->u32_max_value);
- } else if ((s32)reg->u32_min_value < 0) {
- /* Negative. We can't learn anything from the smax, but smin
- * is negative, hence safe.
- */
- reg->s32_min_value = reg->u32_min_value =
- max_t(u32, reg->s32_min_value, reg->u32_min_value);
- reg->s32_max_value = reg->u32_max_value;
+ if ((u32)reg->s32_min_value <= (u32)reg->s32_max_value) {
+ reg->u32_min_value = max_t(u32, reg->s32_min_value, reg->u32_min_value);
+ reg->u32_max_value = min_t(u32, reg->s32_max_value, reg->u32_max_value);
}
}
static void __reg64_deduce_bounds(struct bpf_reg_state *reg)
{
- /* Learn sign from signed bounds.
- * If we cannot cross the sign boundary, then signed and unsigned bounds
+ /* If u64 range forms a valid s64 range (due to matching sign bit),
+ * try to learn from that. Let's do a bit of ASCII art to see when
+ * this is happening. Let's take u64 range first:
+ *
+ * 0 0x7fffffffffffffff 0x8000000000000000 U64_MAX
+ * |-------------------------------|--------------------------------|
+ *
+ * Valid u64 range is formed when umin and umax are anywhere in the
+ * range [0, U64_MAX], and umin <= umax. u64 case is simple and
+ * straightforward. Let's see how s64 range maps onto the same range
+ * of values, annotated below the line for comparison:
+ *
+ * 0 0x7fffffffffffffff 0x8000000000000000 U64_MAX
+ * |-------------------------------|--------------------------------|
+ * 0 S64_MAX S64_MIN -1
+ *
+ * So s64 values basically start in the middle and they are logically
+ * contiguous to the right of it, wrapping around from -1 to 0, and
+ * then finishing as S64_MAX (0x7fffffffffffffff) right before
+ * S64_MIN. We can try drawing the continuity of u64 vs s64 values
+ * more visually as mapped to sign-agnostic range of hex values.
+ *
+ * u64 start u64 end
+ * _______________________________________________________________
+ * / \
+ * 0 0x7fffffffffffffff 0x8000000000000000 U64_MAX
+ * |-------------------------------|--------------------------------|
+ * 0 S64_MAX S64_MIN -1
+ * / \
+ * >------------------------------ ------------------------------->
+ * s64 continues... s64 end s64 start s64 "midpoint"
+ *
+ * What this means is that, in general, we can't always derive
+ * something new about u64 from any random s64 range, and vice versa.
+ *
+ * But we can do that in two particular cases. One is when entire
+ * u64/s64 range is *entirely* contained within left half of the above
+ * diagram or when it is *entirely* contained in the right half. I.e.:
+ *
+ * |-------------------------------|--------------------------------|
+ * ^ ^ ^ ^
+ * A B C D
+ *
+ * [A, B] and [C, D] are contained entirely in their respective halves
+ * and form valid contiguous ranges as both u64 and s64 values. [A, B]
+ * will be non-negative both as u64 and s64 (and in fact it will be
+ * identical ranges no matter the signedness). [C, D] treated as s64
+ * will be a range of negative values, while in u64 it will be
+ * non-negative range of values larger than 0x8000000000000000.
+ *
+ * Now, any other range here can't be represented in both u64 and s64
+ * simultaneously. E.g., [A, C], [A, D], [B, C], [B, D] are valid
+ * contiguous u64 ranges, but they are discontinuous in s64. [B, C]
+ * in s64 would be properly presented as [S64_MIN, C] and [B, S64_MAX],
+ * for example. Similarly, valid s64 range [D, A] (going from negative
+ * to positive values), would be two separate [D, U64_MAX] and [0, A]
+ * ranges as u64. Currently reg_state can't represent two segments per
+ * numeric domain, so in such situations we can only derive maximal
+ * possible range ([0, U64_MAX] for u64, and [S64_MIN, S64_MAX] for s64).
+ *
+ * So we use these facts to derive umin/umax from smin/smax and vice
+ * versa only if they stay within the same "half". This is equivalent
+ * to checking sign bit: lower half will have sign bit as zero, upper
+ * half have sign bit 1. Below in code we simplify this by just
+ * casting umin/umax as smin/smax and checking if they form valid
+ * range, and vice versa. Those are equivalent checks.
+ */
+ if ((s64)reg->umin_value <= (s64)reg->umax_value) {
+ reg->smin_value = max_t(s64, reg->smin_value, reg->umin_value);
+ reg->smax_value = min_t(s64, reg->smax_value, reg->umax_value);
+ }
+ /* If we cannot cross the sign boundary, then signed and unsigned bounds
* are the same, so combine. This works even in the negative case, e.g.
* -3 s<= x s<= -1 implies 0xf...fd u<= x u<= 0xf...ff.
*/
- if (reg->smin_value >= 0 || reg->smax_value < 0) {
- reg->smin_value = reg->umin_value = max_t(u64, reg->smin_value,
- reg->umin_value);
- reg->smax_value = reg->umax_value = min_t(u64, reg->smax_value,
- reg->umax_value);
- return;
+ if ((u64)reg->smin_value <= (u64)reg->smax_value) {
+ reg->umin_value = max_t(u64, reg->smin_value, reg->umin_value);
+ reg->umax_value = min_t(u64, reg->smax_value, reg->umax_value);
}
- /* Learn sign from unsigned bounds. Signed bounds cross the sign
- * boundary, so we must be careful.
+}
+
+static void __reg_deduce_mixed_bounds(struct bpf_reg_state *reg)
+{
+ /* Try to tighten 64-bit bounds from 32-bit knowledge, using 32-bit
+ * values on both sides of 64-bit range in hope to have tigher range.
+ * E.g., if r1 is [0x1'00000000, 0x3'80000000], and we learn from
+ * 32-bit signed > 0 operation that s32 bounds are now [1; 0x7fffffff].
+ * With this, we can substitute 1 as low 32-bits of _low_ 64-bit bound
+ * (0x100000000 -> 0x100000001) and 0x7fffffff as low 32-bits of
+ * _high_ 64-bit bound (0x380000000 -> 0x37fffffff) and arrive at a
+ * better overall bounds for r1 as [0x1'000000001; 0x3'7fffffff].
+ * We just need to make sure that derived bounds we are intersecting
+ * with are well-formed ranges in respecitve s64 or u64 domain, just
+ * like we do with similar kinds of 32-to-64 or 64-to-32 adjustments.
*/
- if ((s64)reg->umax_value >= 0) {
- /* Positive. We can't learn anything from the smin, but smax
- * is positive, hence safe.
- */
- reg->smin_value = reg->umin_value;
- reg->smax_value = reg->umax_value = min_t(u64, reg->smax_value,
- reg->umax_value);
- } else if ((s64)reg->umin_value < 0) {
- /* Negative. We can't learn anything from the smax, but smin
- * is negative, hence safe.
- */
- reg->smin_value = reg->umin_value = max_t(u64, reg->smin_value,
- reg->umin_value);
- reg->smax_value = reg->umax_value;
+ __u64 new_umin, new_umax;
+ __s64 new_smin, new_smax;
+
+ /* u32 -> u64 tightening, it's always well-formed */
+ new_umin = (reg->umin_value & ~0xffffffffULL) | reg->u32_min_value;
+ new_umax = (reg->umax_value & ~0xffffffffULL) | reg->u32_max_value;
+ reg->umin_value = max_t(u64, reg->umin_value, new_umin);
+ reg->umax_value = min_t(u64, reg->umax_value, new_umax);
+ /* u32 -> s64 tightening, u32 range embedded into s64 preserves range validity */
+ new_smin = (reg->smin_value & ~0xffffffffULL) | reg->u32_min_value;
+ new_smax = (reg->smax_value & ~0xffffffffULL) | reg->u32_max_value;
+ reg->smin_value = max_t(s64, reg->smin_value, new_smin);
+ reg->smax_value = min_t(s64, reg->smax_value, new_smax);
+
+ /* if s32 can be treated as valid u32 range, we can use it as well */
+ if ((u32)reg->s32_min_value <= (u32)reg->s32_max_value) {
+ /* s32 -> u64 tightening */
+ new_umin = (reg->umin_value & ~0xffffffffULL) | (u32)reg->s32_min_value;
+ new_umax = (reg->umax_value & ~0xffffffffULL) | (u32)reg->s32_max_value;
+ reg->umin_value = max_t(u64, reg->umin_value, new_umin);
+ reg->umax_value = min_t(u64, reg->umax_value, new_umax);
+ /* s32 -> s64 tightening */
+ new_smin = (reg->smin_value & ~0xffffffffULL) | (u32)reg->s32_min_value;
+ new_smax = (reg->smax_value & ~0xffffffffULL) | (u32)reg->s32_max_value;
+ reg->smin_value = max_t(s64, reg->smin_value, new_smin);
+ reg->smax_value = min_t(s64, reg->smax_value, new_smax);
}
}
@@ -2411,6 +2157,7 @@ static void __reg_deduce_bounds(struct bpf_reg_state *reg)
{
__reg32_deduce_bounds(reg);
__reg64_deduce_bounds(reg);
+ __reg_deduce_mixed_bounds(reg);
}
/* Attempts to improve var_off based on unsigned min/max information */
@@ -2432,6 +2179,7 @@ static void reg_bounds_sync(struct bpf_reg_state *reg)
__update_reg_bounds(reg);
/* We might have learned something about the sign bit. */
__reg_deduce_bounds(reg);
+ __reg_deduce_bounds(reg);
/* We might have learned some bits from the bounds. */
__reg_bound_offset(reg);
/* Intersecting with the old var_off might have improved our bounds
@@ -2441,6 +2189,56 @@ static void reg_bounds_sync(struct bpf_reg_state *reg)
__update_reg_bounds(reg);
}
+static int reg_bounds_sanity_check(struct bpf_verifier_env *env,
+ struct bpf_reg_state *reg, const char *ctx)
+{
+ const char *msg;
+
+ if (reg->umin_value > reg->umax_value ||
+ reg->smin_value > reg->smax_value ||
+ reg->u32_min_value > reg->u32_max_value ||
+ reg->s32_min_value > reg->s32_max_value) {
+ msg = "range bounds violation";
+ goto out;
+ }
+
+ if (tnum_is_const(reg->var_off)) {
+ u64 uval = reg->var_off.value;
+ s64 sval = (s64)uval;
+
+ if (reg->umin_value != uval || reg->umax_value != uval ||
+ reg->smin_value != sval || reg->smax_value != sval) {
+ msg = "const tnum out of sync with range bounds";
+ goto out;
+ }
+ }
+
+ if (tnum_subreg_is_const(reg->var_off)) {
+ u32 uval32 = tnum_subreg(reg->var_off).value;
+ s32 sval32 = (s32)uval32;
+
+ if (reg->u32_min_value != uval32 || reg->u32_max_value != uval32 ||
+ reg->s32_min_value != sval32 || reg->s32_max_value != sval32) {
+ msg = "const subreg tnum out of sync with range bounds";
+ goto out;
+ }
+ }
+
+ return 0;
+out:
+ verbose(env, "REG INVARIANTS VIOLATION (%s): %s u64=[%#llx, %#llx] "
+ "s64=[%#llx, %#llx] u32=[%#x, %#x] s32=[%#x, %#x] var_off=(%#llx, %#llx)\n",
+ ctx, msg, reg->umin_value, reg->umax_value,
+ reg->smin_value, reg->smax_value,
+ reg->u32_min_value, reg->u32_max_value,
+ reg->s32_min_value, reg->s32_max_value,
+ reg->var_off.value, reg->var_off.mask);
+ if (env->test_reg_invariants)
+ return -EFAULT;
+ __mark_reg_unbounded(reg);
+ return 0;
+}
+
static bool __reg32_bound_s64(s32 a)
{
return a >= 0 && a <= S32_MAX;
@@ -2465,51 +2263,6 @@ static void __reg_assign_32_into_64(struct bpf_reg_state *reg)
}
}
-static void __reg_combine_32_into_64(struct bpf_reg_state *reg)
-{
- /* special case when 64-bit register has upper 32-bit register
- * zeroed. Typically happens after zext or <<32, >>32 sequence
- * allowing us to use 32-bit bounds directly,
- */
- if (tnum_equals_const(tnum_clear_subreg(reg->var_off), 0)) {
- __reg_assign_32_into_64(reg);
- } else {
- /* Otherwise the best we can do is push lower 32bit known and
- * unknown bits into register (var_off set from jmp logic)
- * then learn as much as possible from the 64-bit tnum
- * known and unknown bits. The previous smin/smax bounds are
- * invalid here because of jmp32 compare so mark them unknown
- * so they do not impact tnum bounds calculation.
- */
- __mark_reg64_unbounded(reg);
- }
- reg_bounds_sync(reg);
-}
-
-static bool __reg64_bound_s32(s64 a)
-{
- return a >= S32_MIN && a <= S32_MAX;
-}
-
-static bool __reg64_bound_u32(u64 a)
-{
- return a >= U32_MIN && a <= U32_MAX;
-}
-
-static void __reg_combine_64_into_32(struct bpf_reg_state *reg)
-{
- __mark_reg32_unbounded(reg);
- if (__reg64_bound_s32(reg->smin_value) && __reg64_bound_s32(reg->smax_value)) {
- reg->s32_min_value = (s32)reg->smin_value;
- reg->s32_max_value = (s32)reg->smax_value;
- }
- if (__reg64_bound_u32(reg->umin_value) && __reg64_bound_u32(reg->umax_value)) {
- reg->u32_min_value = (u32)reg->umin_value;
- reg->u32_max_value = (u32)reg->umax_value;
- }
- reg_bounds_sync(reg);
-}
-
/* Mark a register as having a completely unknown (scalar) value. */
static void __mark_reg_unknown(const struct bpf_verifier_env *env,
struct bpf_reg_state *reg)
@@ -2597,6 +2350,11 @@ static void init_reg_state(struct bpf_verifier_env *env,
regs[BPF_REG_FP].frameno = state->frameno;
}
+static struct bpf_retval_range retval_range(s32 minval, s32 maxval)
+{
+ return (struct bpf_retval_range){ minval, maxval };
+}
+
#define BPF_MAIN_FUNC (-1)
static void init_func_state(struct bpf_verifier_env *env,
struct bpf_func_state *state,
@@ -2605,7 +2363,7 @@ static void init_func_state(struct bpf_verifier_env *env,
state->callsite = callsite;
state->frameno = frameno;
state->subprogno = subprogno;
- state->callback_ret_range = tnum_range(0, 0);
+ state->callback_ret_range = retval_range(0, 0);
init_reg_state(env, state);
mark_verifier_state_scratched(env);
}
@@ -3149,6 +2907,7 @@ static int add_subprog_and_kfunc(struct bpf_verifier_env *env)
if (env->subprog_info[i].start != ex_cb_insn)
continue;
env->exception_callback_subprog = i;
+ mark_subprog_exc_cb(env, i);
break;
}
}
@@ -3505,6 +3264,21 @@ static int check_reg_arg(struct bpf_verifier_env *env, u32 regno,
return __check_reg_arg(env, state->regs, regno, t);
}
+static int insn_stack_access_flags(int frameno, int spi)
+{
+ return INSN_F_STACK_ACCESS | (spi << INSN_F_SPI_SHIFT) | frameno;
+}
+
+static int insn_stack_access_spi(int insn_flags)
+{
+ return (insn_flags >> INSN_F_SPI_SHIFT) & INSN_F_SPI_MASK;
+}
+
+static int insn_stack_access_frameno(int insn_flags)
+{
+ return insn_flags & INSN_F_FRAMENO_MASK;
+}
+
static void mark_jmp_point(struct bpf_verifier_env *env, int idx)
{
env->insn_aux_data[idx].jmp_point = true;
@@ -3516,28 +3290,51 @@ static bool is_jmp_point(struct bpf_verifier_env *env, int insn_idx)
}
/* for any branch, call, exit record the history of jmps in the given state */
-static int push_jmp_history(struct bpf_verifier_env *env,
- struct bpf_verifier_state *cur)
+static int push_jmp_history(struct bpf_verifier_env *env, struct bpf_verifier_state *cur,
+ int insn_flags)
{
u32 cnt = cur->jmp_history_cnt;
- struct bpf_idx_pair *p;
+ struct bpf_jmp_history_entry *p;
size_t alloc_size;
- if (!is_jmp_point(env, env->insn_idx))
+ /* combine instruction flags if we already recorded this instruction */
+ if (env->cur_hist_ent) {
+ /* atomic instructions push insn_flags twice, for READ and
+ * WRITE sides, but they should agree on stack slot
+ */
+ WARN_ONCE((env->cur_hist_ent->flags & insn_flags) &&
+ (env->cur_hist_ent->flags & insn_flags) != insn_flags,
+ "verifier insn history bug: insn_idx %d cur flags %x new flags %x\n",
+ env->insn_idx, env->cur_hist_ent->flags, insn_flags);
+ env->cur_hist_ent->flags |= insn_flags;
return 0;
+ }
cnt++;
alloc_size = kmalloc_size_roundup(size_mul(cnt, sizeof(*p)));
p = krealloc(cur->jmp_history, alloc_size, GFP_USER);
if (!p)
return -ENOMEM;
- p[cnt - 1].idx = env->insn_idx;
- p[cnt - 1].prev_idx = env->prev_insn_idx;
cur->jmp_history = p;
+
+ p = &cur->jmp_history[cnt - 1];
+ p->idx = env->insn_idx;
+ p->prev_idx = env->prev_insn_idx;
+ p->flags = insn_flags;
cur->jmp_history_cnt = cnt;
+ env->cur_hist_ent = p;
+
return 0;
}
+static struct bpf_jmp_history_entry *get_jmp_hist_entry(struct bpf_verifier_state *st,
+ u32 hist_end, int insn_idx)
+{
+ if (hist_end > 0 && st->jmp_history[hist_end - 1].idx == insn_idx)
+ return &st->jmp_history[hist_end - 1];
+ return NULL;
+}
+
/* Backtrack one insn at a time. If idx is not at the top of recorded
* history then previous instruction came from straight line execution.
* Return -ENOENT if we exhausted all instructions within given state.
@@ -3664,16 +3461,6 @@ static inline void bt_clear_frame_slot(struct backtrack_state *bt, u32 frame, u3
bt->stack_masks[frame] &= ~(1ull << slot);
}
-static inline void bt_set_slot(struct backtrack_state *bt, u32 slot)
-{
- bt_set_frame_slot(bt, bt->frame, slot);
-}
-
-static inline void bt_clear_slot(struct backtrack_state *bt, u32 slot)
-{
- bt_clear_frame_slot(bt, bt->frame, slot);
-}
-
static inline u32 bt_frame_reg_mask(struct backtrack_state *bt, u32 frame)
{
return bt->reg_masks[frame];
@@ -3699,9 +3486,9 @@ static inline bool bt_is_reg_set(struct backtrack_state *bt, u32 reg)
return bt->reg_masks[bt->frame] & (1 << reg);
}
-static inline bool bt_is_slot_set(struct backtrack_state *bt, u32 slot)
+static inline bool bt_is_frame_slot_set(struct backtrack_state *bt, u32 frame, u32 slot)
{
- return bt->stack_masks[bt->frame] & (1ull << slot);
+ return bt->stack_masks[frame] & (1ull << slot);
}
/* format registers bitmask, e.g., "r0,r2,r4" for 0x15 mask */
@@ -3755,7 +3542,7 @@ static bool calls_callback(struct bpf_verifier_env *env, int insn_idx);
* - *was* processed previously during backtracking.
*/
static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
- struct backtrack_state *bt)
+ struct bpf_jmp_history_entry *hist, struct backtrack_state *bt)
{
const struct bpf_insn_cbs cbs = {
.cb_call = disasm_kfunc_name,
@@ -3768,7 +3555,7 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
u8 mode = BPF_MODE(insn->code);
u32 dreg = insn->dst_reg;
u32 sreg = insn->src_reg;
- u32 spi, i;
+ u32 spi, i, fr;
if (insn->code == 0)
return 0;
@@ -3829,20 +3616,15 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
* by 'precise' mark in corresponding register of this state.
* No further tracking necessary.
*/
- if (insn->src_reg != BPF_REG_FP)
+ if (!hist || !(hist->flags & INSN_F_STACK_ACCESS))
return 0;
-
/* dreg = *(u64 *)[fp - off] was a fill from the stack.
* that [fp - off] slot contains scalar that needs to be
* tracked with precision
*/
- spi = (-insn->off - 1) / BPF_REG_SIZE;
- if (spi >= 64) {
- verbose(env, "BUG spi %d\n", spi);
- WARN_ONCE(1, "verifier backtracking bug");
- return -EFAULT;
- }
- bt_set_slot(bt, spi);
+ spi = insn_stack_access_spi(hist->flags);
+ fr = insn_stack_access_frameno(hist->flags);
+ bt_set_frame_slot(bt, fr, spi);
} else if (class == BPF_STX || class == BPF_ST) {
if (bt_is_reg_set(bt, dreg))
/* stx & st shouldn't be using _scalar_ dst_reg
@@ -3851,17 +3633,13 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
*/
return -ENOTSUPP;
/* scalars can only be spilled into stack */
- if (insn->dst_reg != BPF_REG_FP)
+ if (!hist || !(hist->flags & INSN_F_STACK_ACCESS))
return 0;
- spi = (-insn->off - 1) / BPF_REG_SIZE;
- if (spi >= 64) {
- verbose(env, "BUG spi %d\n", spi);
- WARN_ONCE(1, "verifier backtracking bug");
- return -EFAULT;
- }
- if (!bt_is_slot_set(bt, spi))
+ spi = insn_stack_access_spi(hist->flags);
+ fr = insn_stack_access_frameno(hist->flags);
+ if (!bt_is_frame_slot_set(bt, fr, spi))
return 0;
- bt_clear_slot(bt, spi);
+ bt_clear_frame_slot(bt, fr, spi);
if (class == BPF_STX)
bt_set_reg(bt, sreg);
} else if (class == BPF_JMP || class == BPF_JMP32) {
@@ -3905,10 +3683,14 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
WARN_ONCE(1, "verifier backtracking bug");
return -EFAULT;
}
- /* we don't track register spills perfectly,
- * so fallback to force-precise instead of failing */
- if (bt_stack_mask(bt) != 0)
- return -ENOTSUPP;
+ /* we are now tracking register spills correctly,
+ * so any instance of leftover slots is a bug
+ */
+ if (bt_stack_mask(bt) != 0) {
+ verbose(env, "BUG stack slots %llx\n", bt_stack_mask(bt));
+ WARN_ONCE(1, "verifier backtracking bug (subprog leftover stack slots)");
+ return -EFAULT;
+ }
/* propagate r1-r5 to the caller */
for (i = BPF_REG_1; i <= BPF_REG_5; i++) {
if (bt_is_reg_set(bt, i)) {
@@ -3933,8 +3715,11 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
WARN_ONCE(1, "verifier backtracking bug");
return -EFAULT;
}
- if (bt_stack_mask(bt) != 0)
- return -ENOTSUPP;
+ if (bt_stack_mask(bt) != 0) {
+ verbose(env, "BUG stack slots %llx\n", bt_stack_mask(bt));
+ WARN_ONCE(1, "verifier backtracking bug (callback leftover stack slots)");
+ return -EFAULT;
+ }
/* clear r1-r5 in callback subprog's mask */
for (i = BPF_REG_1; i <= BPF_REG_5; i++)
bt_clear_reg(bt, i);
@@ -4371,6 +4156,7 @@ static int __mark_chain_precision(struct bpf_verifier_env *env, int regno)
for (;;) {
DECLARE_BITMAP(mask, 64);
u32 history = st->jmp_history_cnt;
+ struct bpf_jmp_history_entry *hist;
if (env->log.level & BPF_LOG_LEVEL2) {
verbose(env, "mark_precise: frame%d: last_idx %d first_idx %d subseq_idx %d \n",
@@ -4434,7 +4220,8 @@ static int __mark_chain_precision(struct bpf_verifier_env *env, int regno)
err = 0;
skip_first = false;
} else {
- err = backtrack_insn(env, i, subseq_idx, bt);
+ hist = get_jmp_hist_entry(st, history, i);
+ err = backtrack_insn(env, i, subseq_idx, hist, bt);
}
if (err == -ENOTSUPP) {
mark_all_scalars_precise(env, env->cur_state);
@@ -4487,22 +4274,10 @@ static int __mark_chain_precision(struct bpf_verifier_env *env, int regno)
bitmap_from_u64(mask, bt_frame_stack_mask(bt, fr));
for_each_set_bit(i, mask, 64) {
if (i >= func->allocated_stack / BPF_REG_SIZE) {
- /* the sequence of instructions:
- * 2: (bf) r3 = r10
- * 3: (7b) *(u64 *)(r3 -8) = r0
- * 4: (79) r4 = *(u64 *)(r10 -8)
- * doesn't contain jmps. It's backtracked
- * as a single block.
- * During backtracking insn 3 is not recognized as
- * stack access, so at the end of backtracking
- * stack slot fp-8 is still marked in stack_mask.
- * However the parent state may not have accessed
- * fp-8 and it's "unallocated" stack space.
- * In such case fallback to conservative.
- */
- mark_all_scalars_precise(env, env->cur_state);
- bt_reset(bt);
- return 0;
+ verbose(env, "BUG backtracking (stack slot %d, total slots %d)\n",
+ i, func->allocated_stack / BPF_REG_SIZE);
+ WARN_ONCE(1, "verifier backtracking bug (stack slot out of bounds)");
+ return -EFAULT;
}
if (!is_spilled_scalar_reg(&func->stack[i])) {
@@ -4592,9 +4367,17 @@ static bool register_is_null(struct bpf_reg_state *reg)
return reg->type == SCALAR_VALUE && tnum_equals_const(reg->var_off, 0);
}
-static bool register_is_const(struct bpf_reg_state *reg)
+/* check if register is a constant scalar value */
+static bool is_reg_const(struct bpf_reg_state *reg, bool subreg32)
{
- return reg->type == SCALAR_VALUE && tnum_is_const(reg->var_off);
+ return reg->type == SCALAR_VALUE &&
+ tnum_is_const(subreg32 ? tnum_subreg(reg->var_off) : reg->var_off);
+}
+
+/* assuming is_reg_const() is true, return constant value of a register */
+static u64 reg_const_value(struct bpf_reg_state *reg, bool subreg32)
+{
+ return subreg32 ? tnum_subreg(reg->var_off).value : reg->var_off.value;
}
static bool __is_scalar_unbounded(struct bpf_reg_state *reg)
@@ -4631,7 +4414,8 @@ static void copy_register_state(struct bpf_reg_state *dst, const struct bpf_reg_
dst->live = live;
}
-static void save_register_state(struct bpf_func_state *state,
+static void save_register_state(struct bpf_verifier_env *env,
+ struct bpf_func_state *state,
int spi, struct bpf_reg_state *reg,
int size)
{
@@ -4646,7 +4430,7 @@ static void save_register_state(struct bpf_func_state *state,
/* size < 8 bytes spill */
for (; i; i--)
- scrub_spilled_slot(&state->stack[spi].slot_type[i - 1]);
+ mark_stack_slot_misc(env, &state->stack[spi].slot_type[i - 1]);
}
static bool is_bpf_st_mem(struct bpf_insn *insn)
@@ -4667,16 +4451,13 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
int i, slot = -off - 1, spi = slot / BPF_REG_SIZE, err;
struct bpf_insn *insn = &env->prog->insnsi[insn_idx];
struct bpf_reg_state *reg = NULL;
- u32 dst_reg = insn->dst_reg;
+ int insn_flags = insn_stack_access_flags(state->frameno, spi);
- err = grow_stack_state(state, round_up(slot + 1, BPF_REG_SIZE));
- if (err)
- return err;
/* caller checked that off % size == 0 and -MAX_BPF_STACK <= off < 0,
* so it's aligned access and [off, off + size) are within stack limits
*/
if (!env->allow_ptr_leaks &&
- state->stack[spi].slot_type[0] == STACK_SPILL &&
+ is_spilled_reg(&state->stack[spi]) &&
size != BPF_REG_SIZE) {
verbose(env, "attempt to corrupt spilled pointer on stack\n");
return -EACCES;
@@ -4706,20 +4487,8 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
return err;
mark_stack_slot_scratched(env, spi);
- if (reg && !(off % BPF_REG_SIZE) && register_is_bounded(reg) &&
- !register_is_null(reg) && env->bpf_capable) {
- if (dst_reg != BPF_REG_FP) {
- /* The backtracking logic can only recognize explicit
- * stack slot address like [fp - 8]. Other spill of
- * scalar via different register has to be conservative.
- * Backtrack from here and mark all registers as precise
- * that contributed into 'reg' being a constant.
- */
- err = mark_chain_precision(env, value_regno);
- if (err)
- return err;
- }
- save_register_state(state, spi, reg, size);
+ if (reg && !(off % BPF_REG_SIZE) && register_is_bounded(reg) && env->bpf_capable) {
+ save_register_state(env, state, spi, reg, size);
/* Break the relation on a narrowing spill. */
if (fls64(reg->umax_value) > BITS_PER_BYTE * size)
state->stack[spi].spilled_ptr.id = 0;
@@ -4729,7 +4498,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
__mark_reg_known(&fake_reg, insn->imm);
fake_reg.type = SCALAR_VALUE;
- save_register_state(state, spi, &fake_reg, size);
+ save_register_state(env, state, spi, &fake_reg, size);
} else if (reg && is_spillable_regtype(reg->type)) {
/* register containing pointer is being spilled into stack */
if (size != BPF_REG_SIZE) {
@@ -4741,7 +4510,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
verbose(env, "cannot spill pointers to stack into stack frame of the caller\n");
return -EINVAL;
}
- save_register_state(state, spi, reg, size);
+ save_register_state(env, state, spi, reg, size);
} else {
u8 type = STACK_MISC;
@@ -4766,7 +4535,12 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
/* when we zero initialize stack slots mark them as such */
if ((reg && register_is_null(reg)) ||
(!reg && is_bpf_st_mem(insn) && insn->imm == 0)) {
- /* backtracking doesn't work for STACK_ZERO yet. */
+ /* STACK_ZERO case happened because register spill
+ * wasn't properly aligned at the stack slot boundary,
+ * so it's not a register spill anymore; force
+ * originating register to be precise to make
+ * STACK_ZERO correct for subsequent states
+ */
err = mark_chain_precision(env, value_regno);
if (err)
return err;
@@ -4775,9 +4549,12 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
/* Mark slots affected by this stack write. */
for (i = 0; i < size; i++)
- state->stack[spi].slot_type[(slot - i) % BPF_REG_SIZE] =
- type;
+ state->stack[spi].slot_type[(slot - i) % BPF_REG_SIZE] = type;
+ insn_flags = 0; /* not a register spill */
}
+
+ if (insn_flags)
+ return push_jmp_history(env, env->cur_state, insn_flags);
return 0;
}
@@ -4827,10 +4604,6 @@ static int check_stack_write_var_off(struct bpf_verifier_env *env,
(!value_reg && is_bpf_st_mem(insn) && insn->imm == 0))
writing_zero = true;
- err = grow_stack_state(state, round_up(-min_off, BPF_REG_SIZE));
- if (err)
- return err;
-
for (i = min_off; i < max_off; i++) {
int spi;
@@ -4929,21 +4702,10 @@ static void mark_reg_stack_read(struct bpf_verifier_env *env,
zeros++;
}
if (zeros == max_off - min_off) {
- /* any access_size read into register is zero extended,
- * so the whole register == const_zero
+ /* Any access_size read into register is zero extended,
+ * so the whole register == const_zero.
*/
- __mark_reg_const_zero(&state->regs[dst_regno]);
- /* backtracking doesn't support STACK_ZERO yet,
- * so mark it precise here, so that later
- * backtracking can stop here.
- * Backtracking may not need this if this register
- * doesn't participate in pointer adjustment.
- * Forward propagation of precise flag is not
- * necessary either. This mark is only to stop
- * backtracking. Any register that contributed
- * to const 0 was marked precise before spill.
- */
- state->regs[dst_regno].precise = true;
+ __mark_reg_const_zero(env, &state->regs[dst_regno]);
} else {
/* have read misc data from the stack */
mark_reg_unknown(env, state->regs, dst_regno);
@@ -4970,6 +4732,7 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
int i, slot = -off - 1, spi = slot / BPF_REG_SIZE;
struct bpf_reg_state *reg;
u8 *stype, type;
+ int insn_flags = insn_stack_access_flags(reg_state->frameno, spi);
stype = reg_state->stack[spi].slot_type;
reg = &reg_state->stack[spi].spilled_ptr;
@@ -5002,25 +4765,42 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
copy_register_state(&state->regs[dst_regno], reg);
state->regs[dst_regno].subreg_def = subreg_def;
} else {
+ int spill_cnt = 0, zero_cnt = 0;
+
for (i = 0; i < size; i++) {
type = stype[(slot - i) % BPF_REG_SIZE];
- if (type == STACK_SPILL)
+ if (type == STACK_SPILL) {
+ spill_cnt++;
continue;
+ }
if (type == STACK_MISC)
continue;
+ if (type == STACK_ZERO) {
+ zero_cnt++;
+ continue;
+ }
if (type == STACK_INVALID && env->allow_uninit_stack)
continue;
verbose(env, "invalid read from stack off %d+%d size %d\n",
off, i, size);
return -EACCES;
}
- mark_reg_unknown(env, state->regs, dst_regno);
+
+ if (spill_cnt == size &&
+ tnum_is_const(reg->var_off) && reg->var_off.value == 0) {
+ __mark_reg_const_zero(env, &state->regs[dst_regno]);
+ /* this IS register fill, so keep insn_flags */
+ } else if (zero_cnt == size) {
+ /* similarly to mark_reg_stack_read(), preserve zeroes */
+ __mark_reg_const_zero(env, &state->regs[dst_regno]);
+ insn_flags = 0; /* not restoring original register state */
+ } else {
+ mark_reg_unknown(env, state->regs, dst_regno);
+ insn_flags = 0; /* not restoring original register state */
+ }
}
state->regs[dst_regno].live |= REG_LIVE_WRITTEN;
- return 0;
- }
-
- if (dst_regno >= 0) {
+ } else if (dst_regno >= 0) {
/* restore register state from stack */
copy_register_state(&state->regs[dst_regno], reg);
/* mark reg as written since spilled pointer state likely
@@ -5056,7 +4836,10 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
if (dst_regno >= 0)
mark_reg_stack_read(env, reg_state, off, off + size, dst_regno);
+ insn_flags = 0; /* we are not restoring spilled register */
}
+ if (insn_flags)
+ return push_jmp_history(env, env->cur_state, insn_flags);
return 0;
}
@@ -5346,8 +5129,8 @@ static int __check_ptr_off_reg(struct bpf_verifier_env *env,
return 0;
}
-int check_ptr_off_reg(struct bpf_verifier_env *env,
- const struct bpf_reg_state *reg, int regno)
+static int check_ptr_off_reg(struct bpf_verifier_env *env,
+ const struct bpf_reg_state *reg, int regno)
{
return __check_ptr_off_reg(env, reg, regno, false);
}
@@ -5451,10 +5234,23 @@ BTF_SET_END(rcu_protected_types)
static bool rcu_protected_object(const struct btf *btf, u32 btf_id)
{
if (!btf_is_kernel(btf))
- return false;
+ return true;
return btf_id_set_contains(&rcu_protected_types, btf_id);
}
+static struct btf_record *kptr_pointee_btf_record(struct btf_field *kptr_field)
+{
+ struct btf_struct_meta *meta;
+
+ if (btf_is_kernel(kptr_field->kptr.btf))
+ return NULL;
+
+ meta = btf_find_struct_meta(kptr_field->kptr.btf,
+ kptr_field->kptr.btf_id);
+
+ return meta ? meta->record : NULL;
+}
+
static bool rcu_safe_kptr(const struct btf_field *field)
{
const struct btf_field_kptr *kptr = &field->kptr;
@@ -5465,12 +5261,25 @@ static bool rcu_safe_kptr(const struct btf_field *field)
static u32 btf_ld_kptr_type(struct bpf_verifier_env *env, struct btf_field *kptr_field)
{
+ struct btf_record *rec;
+ u32 ret;
+
+ ret = PTR_MAYBE_NULL;
if (rcu_safe_kptr(kptr_field) && in_rcu_cs(env)) {
- if (kptr_field->type != BPF_KPTR_PERCPU)
- return PTR_MAYBE_NULL | MEM_RCU;
- return PTR_MAYBE_NULL | MEM_RCU | MEM_PERCPU;
+ ret |= MEM_RCU;
+ if (kptr_field->type == BPF_KPTR_PERCPU)
+ ret |= MEM_PERCPU;
+ else if (!btf_is_kernel(kptr_field->kptr.btf))
+ ret |= MEM_ALLOC;
+
+ rec = kptr_pointee_btf_record(kptr_field);
+ if (rec && btf_record_has_field(rec, BPF_GRAPH_NODE))
+ ret |= NON_OWN_REF;
+ } else {
+ ret |= PTR_UNTRUSTED;
}
- return PTR_MAYBE_NULL | PTR_UNTRUSTED;
+
+ return ret;
}
static int check_map_kptr_access(struct bpf_verifier_env *env, u32 regno,
@@ -5959,20 +5768,6 @@ static int check_ptr_alignment(struct bpf_verifier_env *env,
strict);
}
-static int update_stack_depth(struct bpf_verifier_env *env,
- const struct bpf_func_state *func,
- int off)
-{
- u16 stack = env->subprog_info[func->subprogno].stack_depth;
-
- if (stack >= -off)
- return 0;
-
- /* update known max for given subprogram */
- env->subprog_info[func->subprogno].stack_depth = -off;
- return 0;
-}
-
/* starting from main bpf function walk all instructions of the function
* and recursively walk all callees that given function can call.
* Ignore jump and exit insns.
@@ -6244,9 +6039,10 @@ static void coerce_reg_to_size(struct bpf_reg_state *reg, int size)
* values are also truncated so we push 64-bit bounds into
* 32-bit bounds. Above were truncated < 32-bits already.
*/
- if (size >= 4)
- return;
- __reg_combine_64_into_32(reg);
+ if (size < 4) {
+ __mark_reg32_unbounded(reg);
+ reg_bounds_sync(reg);
+ }
}
static void set_sext64_default_val(struct bpf_reg_state *reg, int size)
@@ -6761,13 +6557,14 @@ static int check_ptr_to_map_access(struct bpf_verifier_env *env,
* The minimum valid offset is -MAX_BPF_STACK for writes, and
* -state->allocated_stack for reads.
*/
-static int check_stack_slot_within_bounds(int off,
- struct bpf_func_state *state,
- enum bpf_access_type t)
+static int check_stack_slot_within_bounds(struct bpf_verifier_env *env,
+ s64 off,
+ struct bpf_func_state *state,
+ enum bpf_access_type t)
{
int min_valid_off;
- if (t == BPF_WRITE)
+ if (t == BPF_WRITE || env->allow_uninit_stack)
min_valid_off = -MAX_BPF_STACK;
else
min_valid_off = -state->allocated_stack;
@@ -6790,7 +6587,7 @@ static int check_stack_access_within_bounds(
struct bpf_reg_state *regs = cur_regs(env);
struct bpf_reg_state *reg = regs + regno;
struct bpf_func_state *state = func(env, reg);
- int min_off, max_off;
+ s64 min_off, max_off;
int err;
char *err_extra;
@@ -6803,11 +6600,8 @@ static int check_stack_access_within_bounds(
err_extra = " write to";
if (tnum_is_const(reg->var_off)) {
- min_off = reg->var_off.value + off;
- if (access_size > 0)
- max_off = min_off + access_size - 1;
- else
- max_off = min_off;
+ min_off = (s64)reg->var_off.value + off;
+ max_off = min_off + access_size;
} else {
if (reg->smax_value >= BPF_MAX_VAR_OFF ||
reg->smin_value <= -BPF_MAX_VAR_OFF) {
@@ -6816,15 +6610,12 @@ static int check_stack_access_within_bounds(
return -EACCES;
}
min_off = reg->smin_value + off;
- if (access_size > 0)
- max_off = reg->smax_value + off + access_size - 1;
- else
- max_off = min_off;
+ max_off = reg->smax_value + off + access_size;
}
- err = check_stack_slot_within_bounds(min_off, state, type);
- if (!err)
- err = check_stack_slot_within_bounds(max_off, state, type);
+ err = check_stack_slot_within_bounds(env, min_off, state, type);
+ if (!err && max_off > 0)
+ err = -EINVAL; /* out of stack access into non-negative offsets */
if (err) {
if (tnum_is_const(reg->var_off)) {
@@ -6834,11 +6625,16 @@ static int check_stack_access_within_bounds(
char tn_buf[48];
tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
- verbose(env, "invalid variable-offset%s stack R%d var_off=%s size=%d\n",
- err_extra, regno, tn_buf, access_size);
+ verbose(env, "invalid variable-offset%s stack R%d var_off=%s off=%d size=%d\n",
+ err_extra, regno, tn_buf, off, access_size);
}
+ return err;
}
- return err;
+
+ /* Note that there is no stack access with offset zero, so the needed stack
+ * size is -min_off, not -min_off+1.
+ */
+ return grow_stack_state(env, state, -min_off /* size */);
}
/* check whether memory at (regno + off) is accessible for t = (read | write)
@@ -6853,7 +6649,6 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn
{
struct bpf_reg_state *regs = cur_regs(env);
struct bpf_reg_state *reg = regs + regno;
- struct bpf_func_state *state;
int size, err = 0;
size = bpf_size_to_bytes(bpf_size);
@@ -6996,11 +6791,6 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn
if (err)
return err;
- state = func(env, reg);
- err = update_stack_depth(env, state, off);
- if (err)
- return err;
-
if (t == BPF_READ)
err = check_stack_read(env, regno, off, size,
value_regno);
@@ -7189,13 +6979,13 @@ static int check_atomic(struct bpf_verifier_env *env, int insn_idx, struct bpf_i
BPF_SIZE(insn->code), BPF_WRITE, -1, true, false);
if (err)
return err;
-
return 0;
}
/* When register 'regno' is used to read the stack (either directly or through
* a helper function) make sure that it's within stack boundary and, depending
- * on the access type, that all elements of the stack are initialized.
+ * on the access type and privileges, that all elements of the stack are
+ * initialized.
*
* 'off' includes 'regno->off', but not its dynamic part (if any).
*
@@ -7303,8 +7093,11 @@ static int check_stack_range_initialized(
slot = -i - 1;
spi = slot / BPF_REG_SIZE;
- if (state->allocated_stack <= slot)
- goto err;
+ if (state->allocated_stack <= slot) {
+ verbose(env, "verifier bug: allocated_stack too small");
+ return -EFAULT;
+ }
+
stype = &state->stack[spi].slot_type[slot % BPF_REG_SIZE];
if (*stype == STACK_MISC)
goto mark;
@@ -7328,7 +7121,6 @@ static int check_stack_range_initialized(
goto mark;
}
-err:
if (tnum_is_const(reg->var_off)) {
verbose(env, "invalid%s read from stack R%d off %d+%d size %d\n",
err_extra, regno, min_off, i - min_off, access_size);
@@ -7353,7 +7145,7 @@ mark:
* helper may write to the entire memory range.
*/
}
- return update_stack_depth(env, state, min_off);
+ return 0;
}
static int check_helper_mem_access(struct bpf_verifier_env *env, int regno,
@@ -7449,6 +7241,12 @@ static int check_helper_mem_access(struct bpf_verifier_env *env, int regno,
}
}
+/* verify arguments to helpers or kfuncs consisting of a pointer and an access
+ * size.
+ *
+ * @regno is the register containing the access size. regno-1 is the register
+ * containing the pointer.
+ */
static int check_mem_size_reg(struct bpf_verifier_env *env,
struct bpf_reg_state *reg, u32 regno,
bool zero_size_allowed,
@@ -7483,12 +7281,10 @@ static int check_mem_size_reg(struct bpf_verifier_env *env,
return -EACCES;
}
- if (reg->umin_value == 0) {
- err = check_helper_mem_access(env, regno - 1, 0,
- zero_size_allowed,
- meta);
- if (err)
- return err;
+ if (reg->umin_value == 0 && !zero_size_allowed) {
+ verbose(env, "R%d invalid zero-sized read: u64=[%lld,%lld]\n",
+ regno, reg->umin_value, reg->umax_value);
+ return -EACCES;
}
if (reg->umax_value >= BPF_MAX_VAR_SIZ) {
@@ -7504,8 +7300,8 @@ static int check_mem_size_reg(struct bpf_verifier_env *env,
return err;
}
-int check_mem_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg,
- u32 regno, u32 mem_size)
+static int check_mem_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg,
+ u32 regno, u32 mem_size)
{
bool may_be_null = type_may_be_null(reg->type);
struct bpf_reg_state saved_reg;
@@ -8150,7 +7946,7 @@ static int process_iter_next_call(struct bpf_verifier_env *env, int insn_idx,
/* switch to DRAINED state, but keep the depth unchanged */
/* mark current iter state as drained and assume returned NULL */
cur_iter->iter.state = BPF_ITER_STATE_DRAINED;
- __mark_reg_const_zero(&cur_fr->regs[BPF_REG_0]);
+ __mark_reg_const_zero(env, &cur_fr->regs[BPF_REG_0]);
return 0;
}
@@ -8490,9 +8286,9 @@ reg_find_field_offset(const struct bpf_reg_state *reg, s32 off, u32 fields)
return field;
}
-int check_func_arg_reg_off(struct bpf_verifier_env *env,
- const struct bpf_reg_state *reg, int regno,
- enum bpf_arg_type arg_type)
+static int check_func_arg_reg_off(struct bpf_verifier_env *env,
+ const struct bpf_reg_state *reg, int regno,
+ enum bpf_arg_type arg_type)
{
u32 type = reg->type;
@@ -8626,6 +8422,54 @@ static enum bpf_dynptr_type dynptr_get_type(struct bpf_verifier_env *env,
return state->stack[spi].spilled_ptr.dynptr.type;
}
+static int check_reg_const_str(struct bpf_verifier_env *env,
+ struct bpf_reg_state *reg, u32 regno)
+{
+ struct bpf_map *map = reg->map_ptr;
+ int err;
+ int map_off;
+ u64 map_addr;
+ char *str_ptr;
+
+ if (reg->type != PTR_TO_MAP_VALUE)
+ return -EINVAL;
+
+ if (!bpf_map_is_rdonly(map)) {
+ verbose(env, "R%d does not point to a readonly map'\n", regno);
+ return -EACCES;
+ }
+
+ if (!tnum_is_const(reg->var_off)) {
+ verbose(env, "R%d is not a constant address'\n", regno);
+ return -EACCES;
+ }
+
+ if (!map->ops->map_direct_value_addr) {
+ verbose(env, "no direct value access support for this map type\n");
+ return -EACCES;
+ }
+
+ err = check_map_access(env, regno, reg->off,
+ map->value_size - reg->off, false,
+ ACCESS_HELPER);
+ if (err)
+ return err;
+
+ map_off = reg->off + reg->var_off.value;
+ err = map->ops->map_direct_value_addr(map, &map_addr, map_off);
+ if (err) {
+ verbose(env, "direct value access on string failed\n");
+ return err;
+ }
+
+ str_ptr = (char *)(long)(map_addr);
+ if (!strnchr(str_ptr + map_off, map->value_size - map_off, 0)) {
+ verbose(env, "string is not zero-terminated\n");
+ return -EINVAL;
+ }
+ return 0;
+}
+
static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
struct bpf_call_arg_meta *meta,
const struct bpf_func_proto *fn,
@@ -8870,44 +8714,9 @@ skip_type_check:
}
case ARG_PTR_TO_CONST_STR:
{
- struct bpf_map *map = reg->map_ptr;
- int map_off;
- u64 map_addr;
- char *str_ptr;
-
- if (!bpf_map_is_rdonly(map)) {
- verbose(env, "R%d does not point to a readonly map'\n", regno);
- return -EACCES;
- }
-
- if (!tnum_is_const(reg->var_off)) {
- verbose(env, "R%d is not a constant address'\n", regno);
- return -EACCES;
- }
-
- if (!map->ops->map_direct_value_addr) {
- verbose(env, "no direct value access support for this map type\n");
- return -EACCES;
- }
-
- err = check_map_access(env, regno, reg->off,
- map->value_size - reg->off, false,
- ACCESS_HELPER);
+ err = check_reg_const_str(env, reg, regno);
if (err)
return err;
-
- map_off = reg->off + reg->var_off.value;
- err = map->ops->map_direct_value_addr(map, &map_addr, map_off);
- if (err) {
- verbose(env, "direct value access on string failed\n");
- return err;
- }
-
- str_ptr = (char *)(long)(map_addr);
- if (!strnchr(str_ptr + map_off, map->value_size - map_off, 0)) {
- verbose(env, "string is not zero-terminated\n");
- return -EINVAL;
- }
break;
}
case ARG_PTR_TO_KPTR:
@@ -9440,6 +9249,102 @@ err_out:
return err;
}
+static int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog,
+ const struct btf *btf,
+ struct bpf_reg_state *regs)
+{
+ struct bpf_subprog_info *sub = subprog_info(env, subprog);
+ struct bpf_verifier_log *log = &env->log;
+ u32 i;
+ int ret;
+
+ ret = btf_prepare_func_args(env, subprog);
+ if (ret)
+ return ret;
+
+ /* check that BTF function arguments match actual types that the
+ * verifier sees.
+ */
+ for (i = 0; i < sub->arg_cnt; i++) {
+ u32 regno = i + 1;
+ struct bpf_reg_state *reg = &regs[regno];
+ struct bpf_subprog_arg_info *arg = &sub->args[i];
+
+ if (arg->arg_type == ARG_ANYTHING) {
+ if (reg->type != SCALAR_VALUE) {
+ bpf_log(log, "R%d is not a scalar\n", regno);
+ return -EINVAL;
+ }
+ } else if (arg->arg_type == ARG_PTR_TO_CTX) {
+ ret = check_func_arg_reg_off(env, reg, regno, ARG_DONTCARE);
+ if (ret < 0)
+ return ret;
+ /* If function expects ctx type in BTF check that caller
+ * is passing PTR_TO_CTX.
+ */
+ if (reg->type != PTR_TO_CTX) {
+ bpf_log(log, "arg#%d expects pointer to ctx\n", i);
+ return -EINVAL;
+ }
+ } else if (base_type(arg->arg_type) == ARG_PTR_TO_MEM) {
+ ret = check_func_arg_reg_off(env, reg, regno, ARG_DONTCARE);
+ if (ret < 0)
+ return ret;
+ if (check_mem_reg(env, reg, regno, arg->mem_size))
+ return -EINVAL;
+ if (!(arg->arg_type & PTR_MAYBE_NULL) && (reg->type & PTR_MAYBE_NULL)) {
+ bpf_log(log, "arg#%d is expected to be non-NULL\n", i);
+ return -EINVAL;
+ }
+ } else if (arg->arg_type == (ARG_PTR_TO_DYNPTR | MEM_RDONLY)) {
+ ret = process_dynptr_func(env, regno, -1, arg->arg_type, 0);
+ if (ret)
+ return ret;
+ } else {
+ bpf_log(log, "verifier bug: unrecognized arg#%d type %d\n",
+ i, arg->arg_type);
+ return -EFAULT;
+ }
+ }
+
+ return 0;
+}
+
+/* Compare BTF of a function call with given bpf_reg_state.
+ * Returns:
+ * EFAULT - there is a verifier bug. Abort verification.
+ * EINVAL - there is a type mismatch or BTF is not available.
+ * 0 - BTF matches with what bpf_reg_state expects.
+ * Only PTR_TO_CTX and SCALAR_VALUE states are recognized.
+ */
+static int btf_check_subprog_call(struct bpf_verifier_env *env, int subprog,
+ struct bpf_reg_state *regs)
+{
+ struct bpf_prog *prog = env->prog;
+ struct btf *btf = prog->aux->btf;
+ u32 btf_id;
+ int err;
+
+ if (!prog->aux->func_info)
+ return -EINVAL;
+
+ btf_id = prog->aux->func_info[subprog].type_id;
+ if (!btf_id)
+ return -EFAULT;
+
+ if (prog->aux->func_info_aux[subprog].unreliable)
+ return -EINVAL;
+
+ err = btf_check_func_arg_match(env, subprog, btf, regs);
+ /* Compiler optimizations can remove arguments from static functions
+ * or mismatched type can be passed into a global function.
+ * In such cases mark the function as unreliable from BTF point of view.
+ */
+ if (err)
+ prog->aux->func_info_aux[subprog].unreliable = true;
+ return err;
+}
+
static int push_callback_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
int insn_idx, int subprog,
set_callee_state_fn set_callee_state_cb)
@@ -9529,13 +9434,18 @@ static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
if (err == -EFAULT)
return err;
if (subprog_is_global(env, subprog)) {
+ const char *sub_name = subprog_name(env, subprog);
+
if (err) {
- verbose(env, "Caller passes invalid args into func#%d\n", subprog);
+ verbose(env, "Caller passes invalid args into func#%d ('%s')\n",
+ subprog, sub_name);
return err;
}
- if (env->log.level & BPF_LOG_LEVEL)
- verbose(env, "Func#%d is global and valid. Skipping.\n", subprog);
+ verbose(env, "Func#%d ('%s') is global and assumed valid.\n",
+ subprog, sub_name);
+ /* mark global subprog for verifying after main prog */
+ subprog_aux(env, subprog)->called = true;
clear_caller_saved_regs(env, caller->regs);
/* All global functions return a 64-bit SCALAR_VALUE */
@@ -9635,7 +9545,7 @@ static int set_map_elem_callback_state(struct bpf_verifier_env *env,
return err;
callee->in_callback_fn = true;
- callee->callback_ret_range = tnum_range(0, 1);
+ callee->callback_ret_range = retval_range(0, 1);
return 0;
}
@@ -9657,7 +9567,7 @@ static int set_loop_callback_state(struct bpf_verifier_env *env,
__mark_reg_not_init(env, &callee->regs[BPF_REG_5]);
callee->in_callback_fn = true;
- callee->callback_ret_range = tnum_range(0, 1);
+ callee->callback_ret_range = retval_range(0, 1);
return 0;
}
@@ -9687,7 +9597,7 @@ static int set_timer_callback_state(struct bpf_verifier_env *env,
__mark_reg_not_init(env, &callee->regs[BPF_REG_4]);
__mark_reg_not_init(env, &callee->regs[BPF_REG_5]);
callee->in_async_callback_fn = true;
- callee->callback_ret_range = tnum_range(0, 1);
+ callee->callback_ret_range = retval_range(0, 1);
return 0;
}
@@ -9706,7 +9616,7 @@ static int set_find_vma_callback_state(struct bpf_verifier_env *env,
callee->regs[BPF_REG_2].type = PTR_TO_BTF_ID;
__mark_reg_known_zero(&callee->regs[BPF_REG_2]);
callee->regs[BPF_REG_2].btf = btf_vmlinux;
- callee->regs[BPF_REG_2].btf_id = btf_tracing_ids[BTF_TRACING_TYPE_VMA],
+ callee->regs[BPF_REG_2].btf_id = btf_tracing_ids[BTF_TRACING_TYPE_VMA];
/* pointer to stack or null */
callee->regs[BPF_REG_3] = caller->regs[BPF_REG_4];
@@ -9715,7 +9625,7 @@ static int set_find_vma_callback_state(struct bpf_verifier_env *env,
__mark_reg_not_init(env, &callee->regs[BPF_REG_4]);
__mark_reg_not_init(env, &callee->regs[BPF_REG_5]);
callee->in_callback_fn = true;
- callee->callback_ret_range = tnum_range(0, 1);
+ callee->callback_ret_range = retval_range(0, 1);
return 0;
}
@@ -9738,7 +9648,7 @@ static int set_user_ringbuf_callback_state(struct bpf_verifier_env *env,
__mark_reg_not_init(env, &callee->regs[BPF_REG_5]);
callee->in_callback_fn = true;
- callee->callback_ret_range = tnum_range(0, 1);
+ callee->callback_ret_range = retval_range(0, 1);
return 0;
}
@@ -9770,7 +9680,7 @@ static int set_rbtree_add_callback_state(struct bpf_verifier_env *env,
__mark_reg_not_init(env, &callee->regs[BPF_REG_4]);
__mark_reg_not_init(env, &callee->regs[BPF_REG_5]);
callee->in_callback_fn = true;
- callee->callback_ret_range = tnum_range(0, 1);
+ callee->callback_ret_range = retval_range(0, 1);
return 0;
}
@@ -9799,6 +9709,11 @@ static bool in_rbtree_lock_required_cb(struct bpf_verifier_env *env)
return is_rbtree_lock_required_kfunc(kfunc_btf_id);
}
+static bool retval_range_within(struct bpf_retval_range range, const struct bpf_reg_state *reg)
+{
+ return range.minval <= reg->smin_value && reg->smax_value <= range.maxval;
+}
+
static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
{
struct bpf_verifier_state *state = env->cur_state, *prev_st;
@@ -9822,15 +9737,21 @@ static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
caller = state->frame[state->curframe - 1];
if (callee->in_callback_fn) {
- /* enforce R0 return value range [0, 1]. */
- struct tnum range = callee->callback_ret_range;
-
if (r0->type != SCALAR_VALUE) {
verbose(env, "R0 not a scalar value\n");
return -EACCES;
}
- if (!tnum_in(range, r0->var_off)) {
- verbose_invalid_scalar(env, r0, &range, "callback return", "R0");
+
+ /* we are going to rely on register's precise value */
+ err = mark_reg_read(env, r0, r0->parent, REG_LIVE_READ64);
+ err = err ?: mark_chain_precision(env, BPF_REG_0);
+ if (err)
+ return err;
+
+ /* enforce R0 return value range */
+ if (!retval_range_within(callee->callback_ret_range, r0)) {
+ verbose_invalid_scalar(env, r0, callee->callback_ret_range,
+ "At callback return", "R0");
return -EINVAL;
}
if (!calls_callback(env, callee->callsite)) {
@@ -9896,14 +9817,15 @@ static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
return 0;
}
-static void do_refine_retval_range(struct bpf_reg_state *regs, int ret_type,
- int func_id,
- struct bpf_call_arg_meta *meta)
+static int do_refine_retval_range(struct bpf_verifier_env *env,
+ struct bpf_reg_state *regs, int ret_type,
+ int func_id,
+ struct bpf_call_arg_meta *meta)
{
struct bpf_reg_state *ret_reg = &regs[BPF_REG_0];
if (ret_type != RET_INTEGER)
- return;
+ return 0;
switch (func_id) {
case BPF_FUNC_get_stack:
@@ -9929,6 +9851,8 @@ static void do_refine_retval_range(struct bpf_reg_state *regs, int ret_type,
reg_bounds_sync(ret_reg);
break;
}
+
+ return reg_bounds_sanity_check(env, ret_reg, "retval");
}
static int
@@ -9998,7 +9922,7 @@ record_func_key(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
val = reg->var_off.value;
max = map->max_entries;
- if (!(register_is_const(reg) && val < max)) {
+ if (!(is_reg_const(reg, false) && val < max)) {
bpf_map_key_store(aux, BPF_MAP_KEY_POISON);
return 0;
}
@@ -10593,7 +10517,9 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
regs[BPF_REG_0].ref_obj_id = id;
}
- do_refine_retval_range(regs, fn->ret_type, func_id, &meta);
+ err = do_refine_retval_range(env, regs, fn->ret_type, func_id, &meta);
+ if (err)
+ return err;
err = check_map_func_compatibility(env, meta.map_ptr, func_id);
if (err)
@@ -10771,6 +10697,11 @@ static bool is_kfunc_arg_nullable(const struct btf *btf, const struct btf_param
return __kfunc_param_match_suffix(btf, arg, "__nullable");
}
+static bool is_kfunc_arg_const_str(const struct btf *btf, const struct btf_param *arg)
+{
+ return __kfunc_param_match_suffix(btf, arg, "__str");
+}
+
static bool is_kfunc_arg_scalar_with_name(const struct btf *btf,
const struct btf_param *arg,
const char *name)
@@ -10914,6 +10845,7 @@ enum kfunc_ptr_arg_type {
KF_ARG_PTR_TO_RB_ROOT,
KF_ARG_PTR_TO_RB_NODE,
KF_ARG_PTR_TO_NULL,
+ KF_ARG_PTR_TO_CONST_STR,
};
enum special_kfunc_type {
@@ -11064,6 +10996,9 @@ get_kfunc_ptr_arg_type(struct bpf_verifier_env *env,
if (is_kfunc_arg_rbtree_node(meta->btf, &args[argno]))
return KF_ARG_PTR_TO_RB_NODE;
+ if (is_kfunc_arg_const_str(meta->btf, &args[argno]))
+ return KF_ARG_PTR_TO_CONST_STR;
+
if ((base_type(reg->type) == PTR_TO_BTF_ID || reg2btf_ids[base_type(reg->type)])) {
if (!btf_type_is_struct(ref_t)) {
verbose(env, "kernel function %s args#%d pointer type %s %s is not supported\n",
@@ -11695,6 +11630,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_
case KF_ARG_PTR_TO_MEM_SIZE:
case KF_ARG_PTR_TO_CALLBACK:
case KF_ARG_PTR_TO_REFCOUNTED_KPTR:
+ case KF_ARG_PTR_TO_CONST_STR:
/* Trusted by default */
break;
default:
@@ -11966,6 +11902,15 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_
meta->arg_btf = reg->btf;
meta->arg_btf_id = reg->btf_id;
break;
+ case KF_ARG_PTR_TO_CONST_STR:
+ if (reg->type != PTR_TO_MAP_VALUE) {
+ verbose(env, "arg#%d doesn't point to a const string\n", i);
+ return -EINVAL;
+ }
+ ret = check_reg_const_str(env, reg, regno);
+ if (ret)
+ return ret;
+ break;
}
}
@@ -12020,7 +11965,7 @@ static int fetch_kfunc_meta(struct bpf_verifier_env *env,
return 0;
}
-static int check_return_code(struct bpf_verifier_env *env, int regno);
+static int check_return_code(struct bpf_verifier_env *env, int regno, const char *reg_name);
static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
int *insn_idx_p)
@@ -12157,7 +12102,7 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
* to bpf_throw becomes the return value of the program.
*/
if (!env->exception_callback_subprog) {
- err = check_return_code(env, BPF_REG_1);
+ err = check_return_code(env, BPF_REG_1, "R1");
if (err < 0)
return err;
}
@@ -12196,20 +12141,6 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
if (meta.func_id == special_kfunc_list[KF_bpf_obj_new_impl] && !bpf_global_ma_set)
return -ENOMEM;
- if (meta.func_id == special_kfunc_list[KF_bpf_percpu_obj_new_impl]) {
- if (!bpf_global_percpu_ma_set) {
- mutex_lock(&bpf_percpu_ma_lock);
- if (!bpf_global_percpu_ma_set) {
- err = bpf_mem_alloc_init(&bpf_global_percpu_ma, 0, true);
- if (!err)
- bpf_global_percpu_ma_set = true;
- }
- mutex_unlock(&bpf_percpu_ma_lock);
- if (err)
- return err;
- }
- }
-
if (((u64)(u32)meta.arg_constant.value) != meta.arg_constant.value) {
verbose(env, "local type ID argument must be in range [0, U32_MAX]\n");
return -EINVAL;
@@ -12230,6 +12161,35 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
return -EINVAL;
}
+ if (meta.func_id == special_kfunc_list[KF_bpf_percpu_obj_new_impl]) {
+ if (ret_t->size > BPF_GLOBAL_PERCPU_MA_MAX_SIZE) {
+ verbose(env, "bpf_percpu_obj_new type size (%d) is greater than %d\n",
+ ret_t->size, BPF_GLOBAL_PERCPU_MA_MAX_SIZE);
+ return -EINVAL;
+ }
+
+ if (!bpf_global_percpu_ma_set) {
+ mutex_lock(&bpf_percpu_ma_lock);
+ if (!bpf_global_percpu_ma_set) {
+ /* Charge memory allocated with bpf_global_percpu_ma to
+ * root memcg. The obj_cgroup for root memcg is NULL.
+ */
+ err = bpf_mem_alloc_percpu_init(&bpf_global_percpu_ma, NULL);
+ if (!err)
+ bpf_global_percpu_ma_set = true;
+ }
+ mutex_unlock(&bpf_percpu_ma_lock);
+ if (err)
+ return err;
+ }
+
+ mutex_lock(&bpf_percpu_ma_lock);
+ err = bpf_mem_alloc_percpu_unit_init(&bpf_global_percpu_ma, ret_t->size);
+ mutex_unlock(&bpf_percpu_ma_lock);
+ if (err)
+ return err;
+ }
+
struct_meta = btf_find_struct_meta(ret_btf, ret_btf_id);
if (meta.func_id == special_kfunc_list[KF_bpf_percpu_obj_new_impl]) {
if (!__btf_type_is_scalar_struct(env, ret_btf, ret_t, 0)) {
@@ -14086,13 +14046,12 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
/* check dest operand */
err = check_reg_arg(env, insn->dst_reg, DST_OP_NO_MARK);
+ err = err ?: adjust_reg_min_max_vals(env, insn);
if (err)
return err;
-
- return adjust_reg_min_max_vals(env, insn);
}
- return 0;
+ return reg_bounds_sanity_check(env, &regs[insn->dst_reg], "alu");
}
static void find_good_pkt_pointers(struct bpf_verifier_state *vstate,
@@ -14174,161 +14133,130 @@ static void find_good_pkt_pointers(struct bpf_verifier_state *vstate,
}));
}
-static int is_branch32_taken(struct bpf_reg_state *reg, u32 val, u8 opcode)
-{
- struct tnum subreg = tnum_subreg(reg->var_off);
- s32 sval = (s32)val;
-
- switch (opcode) {
- case BPF_JEQ:
- if (tnum_is_const(subreg))
- return !!tnum_equals_const(subreg, val);
- else if (val < reg->u32_min_value || val > reg->u32_max_value)
- return 0;
- else if (sval < reg->s32_min_value || sval > reg->s32_max_value)
- return 0;
- break;
- case BPF_JNE:
- if (tnum_is_const(subreg))
- return !tnum_equals_const(subreg, val);
- else if (val < reg->u32_min_value || val > reg->u32_max_value)
- return 1;
- else if (sval < reg->s32_min_value || sval > reg->s32_max_value)
- return 1;
- break;
- case BPF_JSET:
- if ((~subreg.mask & subreg.value) & val)
- return 1;
- if (!((subreg.mask | subreg.value) & val))
- return 0;
- break;
- case BPF_JGT:
- if (reg->u32_min_value > val)
- return 1;
- else if (reg->u32_max_value <= val)
- return 0;
- break;
- case BPF_JSGT:
- if (reg->s32_min_value > sval)
- return 1;
- else if (reg->s32_max_value <= sval)
- return 0;
- break;
- case BPF_JLT:
- if (reg->u32_max_value < val)
- return 1;
- else if (reg->u32_min_value >= val)
- return 0;
- break;
- case BPF_JSLT:
- if (reg->s32_max_value < sval)
- return 1;
- else if (reg->s32_min_value >= sval)
- return 0;
- break;
- case BPF_JGE:
- if (reg->u32_min_value >= val)
- return 1;
- else if (reg->u32_max_value < val)
- return 0;
- break;
- case BPF_JSGE:
- if (reg->s32_min_value >= sval)
- return 1;
- else if (reg->s32_max_value < sval)
- return 0;
- break;
- case BPF_JLE:
- if (reg->u32_max_value <= val)
- return 1;
- else if (reg->u32_min_value > val)
- return 0;
- break;
- case BPF_JSLE:
- if (reg->s32_max_value <= sval)
- return 1;
- else if (reg->s32_min_value > sval)
- return 0;
- break;
- }
-
- return -1;
-}
-
-
-static int is_branch64_taken(struct bpf_reg_state *reg, u64 val, u8 opcode)
-{
- s64 sval = (s64)val;
+/*
+ * <reg1> <op> <reg2>, currently assuming reg2 is a constant
+ */
+static int is_scalar_branch_taken(struct bpf_reg_state *reg1, struct bpf_reg_state *reg2,
+ u8 opcode, bool is_jmp32)
+{
+ struct tnum t1 = is_jmp32 ? tnum_subreg(reg1->var_off) : reg1->var_off;
+ struct tnum t2 = is_jmp32 ? tnum_subreg(reg2->var_off) : reg2->var_off;
+ u64 umin1 = is_jmp32 ? (u64)reg1->u32_min_value : reg1->umin_value;
+ u64 umax1 = is_jmp32 ? (u64)reg1->u32_max_value : reg1->umax_value;
+ s64 smin1 = is_jmp32 ? (s64)reg1->s32_min_value : reg1->smin_value;
+ s64 smax1 = is_jmp32 ? (s64)reg1->s32_max_value : reg1->smax_value;
+ u64 umin2 = is_jmp32 ? (u64)reg2->u32_min_value : reg2->umin_value;
+ u64 umax2 = is_jmp32 ? (u64)reg2->u32_max_value : reg2->umax_value;
+ s64 smin2 = is_jmp32 ? (s64)reg2->s32_min_value : reg2->smin_value;
+ s64 smax2 = is_jmp32 ? (s64)reg2->s32_max_value : reg2->smax_value;
switch (opcode) {
case BPF_JEQ:
- if (tnum_is_const(reg->var_off))
- return !!tnum_equals_const(reg->var_off, val);
- else if (val < reg->umin_value || val > reg->umax_value)
+ /* constants, umin/umax and smin/smax checks would be
+ * redundant in this case because they all should match
+ */
+ if (tnum_is_const(t1) && tnum_is_const(t2))
+ return t1.value == t2.value;
+ /* non-overlapping ranges */
+ if (umin1 > umax2 || umax1 < umin2)
return 0;
- else if (sval < reg->smin_value || sval > reg->smax_value)
+ if (smin1 > smax2 || smax1 < smin2)
return 0;
+ if (!is_jmp32) {
+ /* if 64-bit ranges are inconclusive, see if we can
+ * utilize 32-bit subrange knowledge to eliminate
+ * branches that can't be taken a priori
+ */
+ if (reg1->u32_min_value > reg2->u32_max_value ||
+ reg1->u32_max_value < reg2->u32_min_value)
+ return 0;
+ if (reg1->s32_min_value > reg2->s32_max_value ||
+ reg1->s32_max_value < reg2->s32_min_value)
+ return 0;
+ }
break;
case BPF_JNE:
- if (tnum_is_const(reg->var_off))
- return !tnum_equals_const(reg->var_off, val);
- else if (val < reg->umin_value || val > reg->umax_value)
+ /* constants, umin/umax and smin/smax checks would be
+ * redundant in this case because they all should match
+ */
+ if (tnum_is_const(t1) && tnum_is_const(t2))
+ return t1.value != t2.value;
+ /* non-overlapping ranges */
+ if (umin1 > umax2 || umax1 < umin2)
return 1;
- else if (sval < reg->smin_value || sval > reg->smax_value)
+ if (smin1 > smax2 || smax1 < smin2)
return 1;
+ if (!is_jmp32) {
+ /* if 64-bit ranges are inconclusive, see if we can
+ * utilize 32-bit subrange knowledge to eliminate
+ * branches that can't be taken a priori
+ */
+ if (reg1->u32_min_value > reg2->u32_max_value ||
+ reg1->u32_max_value < reg2->u32_min_value)
+ return 1;
+ if (reg1->s32_min_value > reg2->s32_max_value ||
+ reg1->s32_max_value < reg2->s32_min_value)
+ return 1;
+ }
break;
case BPF_JSET:
- if ((~reg->var_off.mask & reg->var_off.value) & val)
+ if (!is_reg_const(reg2, is_jmp32)) {
+ swap(reg1, reg2);
+ swap(t1, t2);
+ }
+ if (!is_reg_const(reg2, is_jmp32))
+ return -1;
+ if ((~t1.mask & t1.value) & t2.value)
return 1;
- if (!((reg->var_off.mask | reg->var_off.value) & val))
+ if (!((t1.mask | t1.value) & t2.value))
return 0;
break;
case BPF_JGT:
- if (reg->umin_value > val)
+ if (umin1 > umax2)
return 1;
- else if (reg->umax_value <= val)
+ else if (umax1 <= umin2)
return 0;
break;
case BPF_JSGT:
- if (reg->smin_value > sval)
+ if (smin1 > smax2)
return 1;
- else if (reg->smax_value <= sval)
+ else if (smax1 <= smin2)
return 0;
break;
case BPF_JLT:
- if (reg->umax_value < val)
+ if (umax1 < umin2)
return 1;
- else if (reg->umin_value >= val)
+ else if (umin1 >= umax2)
return 0;
break;
case BPF_JSLT:
- if (reg->smax_value < sval)
+ if (smax1 < smin2)
return 1;
- else if (reg->smin_value >= sval)
+ else if (smin1 >= smax2)
return 0;
break;
case BPF_JGE:
- if (reg->umin_value >= val)
+ if (umin1 >= umax2)
return 1;
- else if (reg->umax_value < val)
+ else if (umax1 < umin2)
return 0;
break;
case BPF_JSGE:
- if (reg->smin_value >= sval)
+ if (smin1 >= smax2)
return 1;
- else if (reg->smax_value < sval)
+ else if (smax1 < smin2)
return 0;
break;
case BPF_JLE:
- if (reg->umax_value <= val)
+ if (umax1 <= umin2)
return 1;
- else if (reg->umin_value > val)
+ else if (umin1 > umax2)
return 0;
break;
case BPF_JSLE:
- if (reg->smax_value <= sval)
+ if (smax1 <= smin2)
return 1;
- else if (reg->smin_value > sval)
+ else if (smin1 > smax2)
return 0;
break;
}
@@ -14336,41 +14264,6 @@ static int is_branch64_taken(struct bpf_reg_state *reg, u64 val, u8 opcode)
return -1;
}
-/* compute branch direction of the expression "if (reg opcode val) goto target;"
- * and return:
- * 1 - branch will be taken and "goto target" will be executed
- * 0 - branch will not be taken and fall-through to next insn
- * -1 - unknown. Example: "if (reg < 5)" is unknown when register value
- * range [0,10]
- */
-static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode,
- bool is_jmp32)
-{
- if (__is_pointer_value(false, reg)) {
- if (!reg_not_null(reg))
- return -1;
-
- /* If pointer is valid tests against zero will fail so we can
- * use this to direct branch taken.
- */
- if (val != 0)
- return -1;
-
- switch (opcode) {
- case BPF_JEQ:
- return 0;
- case BPF_JNE:
- return 1;
- default:
- return -1;
- }
- }
-
- if (is_jmp32)
- return is_branch32_taken(reg, val, opcode);
- return is_branch64_taken(reg, val, opcode);
-}
-
static int flip_opcode(u32 opcode)
{
/* How can we transform "a <op> b" into "b <op> a"? */
@@ -14432,216 +14325,280 @@ static int is_pkt_ptr_branch_taken(struct bpf_reg_state *dst_reg,
return -1;
}
-/* Adjusts the register min/max values in the case that the dst_reg is the
- * variable register that we are working on, and src_reg is a constant or we're
- * simply doing a BPF_K check.
- * In JEQ/JNE cases we also adjust the var_off values.
+/* compute branch direction of the expression "if (<reg1> opcode <reg2>) goto target;"
+ * and return:
+ * 1 - branch will be taken and "goto target" will be executed
+ * 0 - branch will not be taken and fall-through to next insn
+ * -1 - unknown. Example: "if (reg1 < 5)" is unknown when register value
+ * range [0,10]
*/
-static void reg_set_min_max(struct bpf_reg_state *true_reg,
- struct bpf_reg_state *false_reg,
- u64 val, u32 val32,
- u8 opcode, bool is_jmp32)
-{
- struct tnum false_32off = tnum_subreg(false_reg->var_off);
- struct tnum false_64off = false_reg->var_off;
- struct tnum true_32off = tnum_subreg(true_reg->var_off);
- struct tnum true_64off = true_reg->var_off;
- s64 sval = (s64)val;
- s32 sval32 = (s32)val32;
-
- /* If the dst_reg is a pointer, we can't learn anything about its
- * variable offset from the compare (unless src_reg were a pointer into
- * the same object, but we don't bother with that.
- * Since false_reg and true_reg have the same type by construction, we
- * only need to check one of them for pointerness.
- */
- if (__is_pointer_value(false, false_reg))
- return;
+static int is_branch_taken(struct bpf_reg_state *reg1, struct bpf_reg_state *reg2,
+ u8 opcode, bool is_jmp32)
+{
+ if (reg_is_pkt_pointer_any(reg1) && reg_is_pkt_pointer_any(reg2) && !is_jmp32)
+ return is_pkt_ptr_branch_taken(reg1, reg2, opcode);
+ if (__is_pointer_value(false, reg1) || __is_pointer_value(false, reg2)) {
+ u64 val;
+
+ /* arrange that reg2 is a scalar, and reg1 is a pointer */
+ if (!is_reg_const(reg2, is_jmp32)) {
+ opcode = flip_opcode(opcode);
+ swap(reg1, reg2);
+ }
+ /* and ensure that reg2 is a constant */
+ if (!is_reg_const(reg2, is_jmp32))
+ return -1;
+
+ if (!reg_not_null(reg1))
+ return -1;
+
+ /* If pointer is valid tests against zero will fail so we can
+ * use this to direct branch taken.
+ */
+ val = reg_const_value(reg2, is_jmp32);
+ if (val != 0)
+ return -1;
+
+ switch (opcode) {
+ case BPF_JEQ:
+ return 0;
+ case BPF_JNE:
+ return 1;
+ default:
+ return -1;
+ }
+ }
+
+ /* now deal with two scalars, but not necessarily constants */
+ return is_scalar_branch_taken(reg1, reg2, opcode, is_jmp32);
+}
+
+/* Opcode that corresponds to a *false* branch condition.
+ * E.g., if r1 < r2, then reverse (false) condition is r1 >= r2
+ */
+static u8 rev_opcode(u8 opcode)
+{
switch (opcode) {
- /* JEQ/JNE comparison doesn't change the register equivalence.
- *
- * r1 = r2;
- * if (r1 == 42) goto label;
- * ...
- * label: // here both r1 and r2 are known to be 42.
- *
- * Hence when marking register as known preserve it's ID.
+ case BPF_JEQ: return BPF_JNE;
+ case BPF_JNE: return BPF_JEQ;
+ /* JSET doesn't have it's reverse opcode in BPF, so add
+ * BPF_X flag to denote the reverse of that operation
*/
+ case BPF_JSET: return BPF_JSET | BPF_X;
+ case BPF_JSET | BPF_X: return BPF_JSET;
+ case BPF_JGE: return BPF_JLT;
+ case BPF_JGT: return BPF_JLE;
+ case BPF_JLE: return BPF_JGT;
+ case BPF_JLT: return BPF_JGE;
+ case BPF_JSGE: return BPF_JSLT;
+ case BPF_JSGT: return BPF_JSLE;
+ case BPF_JSLE: return BPF_JSGT;
+ case BPF_JSLT: return BPF_JSGE;
+ default: return 0;
+ }
+}
+
+/* Refine range knowledge for <reg1> <op> <reg>2 conditional operation. */
+static void regs_refine_cond_op(struct bpf_reg_state *reg1, struct bpf_reg_state *reg2,
+ u8 opcode, bool is_jmp32)
+{
+ struct tnum t;
+ u64 val;
+
+again:
+ switch (opcode) {
case BPF_JEQ:
if (is_jmp32) {
- __mark_reg32_known(true_reg, val32);
- true_32off = tnum_subreg(true_reg->var_off);
+ reg1->u32_min_value = max(reg1->u32_min_value, reg2->u32_min_value);
+ reg1->u32_max_value = min(reg1->u32_max_value, reg2->u32_max_value);
+ reg1->s32_min_value = max(reg1->s32_min_value, reg2->s32_min_value);
+ reg1->s32_max_value = min(reg1->s32_max_value, reg2->s32_max_value);
+ reg2->u32_min_value = reg1->u32_min_value;
+ reg2->u32_max_value = reg1->u32_max_value;
+ reg2->s32_min_value = reg1->s32_min_value;
+ reg2->s32_max_value = reg1->s32_max_value;
+
+ t = tnum_intersect(tnum_subreg(reg1->var_off), tnum_subreg(reg2->var_off));
+ reg1->var_off = tnum_with_subreg(reg1->var_off, t);
+ reg2->var_off = tnum_with_subreg(reg2->var_off, t);
} else {
- ___mark_reg_known(true_reg, val);
- true_64off = true_reg->var_off;
+ reg1->umin_value = max(reg1->umin_value, reg2->umin_value);
+ reg1->umax_value = min(reg1->umax_value, reg2->umax_value);
+ reg1->smin_value = max(reg1->smin_value, reg2->smin_value);
+ reg1->smax_value = min(reg1->smax_value, reg2->smax_value);
+ reg2->umin_value = reg1->umin_value;
+ reg2->umax_value = reg1->umax_value;
+ reg2->smin_value = reg1->smin_value;
+ reg2->smax_value = reg1->smax_value;
+
+ reg1->var_off = tnum_intersect(reg1->var_off, reg2->var_off);
+ reg2->var_off = reg1->var_off;
}
break;
case BPF_JNE:
+ if (!is_reg_const(reg2, is_jmp32))
+ swap(reg1, reg2);
+ if (!is_reg_const(reg2, is_jmp32))
+ break;
+
+ /* try to recompute the bound of reg1 if reg2 is a const and
+ * is exactly the edge of reg1.
+ */
+ val = reg_const_value(reg2, is_jmp32);
if (is_jmp32) {
- __mark_reg32_known(false_reg, val32);
- false_32off = tnum_subreg(false_reg->var_off);
+ /* u32_min_value is not equal to 0xffffffff at this point,
+ * because otherwise u32_max_value is 0xffffffff as well,
+ * in such a case both reg1 and reg2 would be constants,
+ * jump would be predicted and reg_set_min_max() won't
+ * be called.
+ *
+ * Same reasoning works for all {u,s}{min,max}{32,64} cases
+ * below.
+ */
+ if (reg1->u32_min_value == (u32)val)
+ reg1->u32_min_value++;
+ if (reg1->u32_max_value == (u32)val)
+ reg1->u32_max_value--;
+ if (reg1->s32_min_value == (s32)val)
+ reg1->s32_min_value++;
+ if (reg1->s32_max_value == (s32)val)
+ reg1->s32_max_value--;
} else {
- ___mark_reg_known(false_reg, val);
- false_64off = false_reg->var_off;
+ if (reg1->umin_value == (u64)val)
+ reg1->umin_value++;
+ if (reg1->umax_value == (u64)val)
+ reg1->umax_value--;
+ if (reg1->smin_value == (s64)val)
+ reg1->smin_value++;
+ if (reg1->smax_value == (s64)val)
+ reg1->smax_value--;
}
break;
case BPF_JSET:
+ if (!is_reg_const(reg2, is_jmp32))
+ swap(reg1, reg2);
+ if (!is_reg_const(reg2, is_jmp32))
+ break;
+ val = reg_const_value(reg2, is_jmp32);
+ /* BPF_JSET (i.e., TRUE branch, *not* BPF_JSET | BPF_X)
+ * requires single bit to learn something useful. E.g., if we
+ * know that `r1 & 0x3` is true, then which bits (0, 1, or both)
+ * are actually set? We can learn something definite only if
+ * it's a single-bit value to begin with.
+ *
+ * BPF_JSET | BPF_X (i.e., negation of BPF_JSET) doesn't have
+ * this restriction. I.e., !(r1 & 0x3) means neither bit 0 nor
+ * bit 1 is set, which we can readily use in adjustments.
+ */
+ if (!is_power_of_2(val))
+ break;
if (is_jmp32) {
- false_32off = tnum_and(false_32off, tnum_const(~val32));
- if (is_power_of_2(val32))
- true_32off = tnum_or(true_32off,
- tnum_const(val32));
+ t = tnum_or(tnum_subreg(reg1->var_off), tnum_const(val));
+ reg1->var_off = tnum_with_subreg(reg1->var_off, t);
} else {
- false_64off = tnum_and(false_64off, tnum_const(~val));
- if (is_power_of_2(val))
- true_64off = tnum_or(true_64off,
- tnum_const(val));
+ reg1->var_off = tnum_or(reg1->var_off, tnum_const(val));
}
break;
- case BPF_JGE:
- case BPF_JGT:
- {
+ case BPF_JSET | BPF_X: /* reverse of BPF_JSET, see rev_opcode() */
+ if (!is_reg_const(reg2, is_jmp32))
+ swap(reg1, reg2);
+ if (!is_reg_const(reg2, is_jmp32))
+ break;
+ val = reg_const_value(reg2, is_jmp32);
if (is_jmp32) {
- u32 false_umax = opcode == BPF_JGT ? val32 : val32 - 1;
- u32 true_umin = opcode == BPF_JGT ? val32 + 1 : val32;
-
- false_reg->u32_max_value = min(false_reg->u32_max_value,
- false_umax);
- true_reg->u32_min_value = max(true_reg->u32_min_value,
- true_umin);
+ t = tnum_and(tnum_subreg(reg1->var_off), tnum_const(~val));
+ reg1->var_off = tnum_with_subreg(reg1->var_off, t);
} else {
- u64 false_umax = opcode == BPF_JGT ? val : val - 1;
- u64 true_umin = opcode == BPF_JGT ? val + 1 : val;
-
- false_reg->umax_value = min(false_reg->umax_value, false_umax);
- true_reg->umin_value = max(true_reg->umin_value, true_umin);
+ reg1->var_off = tnum_and(reg1->var_off, tnum_const(~val));
}
break;
- }
- case BPF_JSGE:
- case BPF_JSGT:
- {
+ case BPF_JLE:
if (is_jmp32) {
- s32 false_smax = opcode == BPF_JSGT ? sval32 : sval32 - 1;
- s32 true_smin = opcode == BPF_JSGT ? sval32 + 1 : sval32;
-
- false_reg->s32_max_value = min(false_reg->s32_max_value, false_smax);
- true_reg->s32_min_value = max(true_reg->s32_min_value, true_smin);
+ reg1->u32_max_value = min(reg1->u32_max_value, reg2->u32_max_value);
+ reg2->u32_min_value = max(reg1->u32_min_value, reg2->u32_min_value);
} else {
- s64 false_smax = opcode == BPF_JSGT ? sval : sval - 1;
- s64 true_smin = opcode == BPF_JSGT ? sval + 1 : sval;
-
- false_reg->smax_value = min(false_reg->smax_value, false_smax);
- true_reg->smin_value = max(true_reg->smin_value, true_smin);
+ reg1->umax_value = min(reg1->umax_value, reg2->umax_value);
+ reg2->umin_value = max(reg1->umin_value, reg2->umin_value);
}
break;
- }
- case BPF_JLE:
case BPF_JLT:
- {
if (is_jmp32) {
- u32 false_umin = opcode == BPF_JLT ? val32 : val32 + 1;
- u32 true_umax = opcode == BPF_JLT ? val32 - 1 : val32;
-
- false_reg->u32_min_value = max(false_reg->u32_min_value,
- false_umin);
- true_reg->u32_max_value = min(true_reg->u32_max_value,
- true_umax);
+ reg1->u32_max_value = min(reg1->u32_max_value, reg2->u32_max_value - 1);
+ reg2->u32_min_value = max(reg1->u32_min_value + 1, reg2->u32_min_value);
} else {
- u64 false_umin = opcode == BPF_JLT ? val : val + 1;
- u64 true_umax = opcode == BPF_JLT ? val - 1 : val;
-
- false_reg->umin_value = max(false_reg->umin_value, false_umin);
- true_reg->umax_value = min(true_reg->umax_value, true_umax);
+ reg1->umax_value = min(reg1->umax_value, reg2->umax_value - 1);
+ reg2->umin_value = max(reg1->umin_value + 1, reg2->umin_value);
}
break;
- }
case BPF_JSLE:
+ if (is_jmp32) {
+ reg1->s32_max_value = min(reg1->s32_max_value, reg2->s32_max_value);
+ reg2->s32_min_value = max(reg1->s32_min_value, reg2->s32_min_value);
+ } else {
+ reg1->smax_value = min(reg1->smax_value, reg2->smax_value);
+ reg2->smin_value = max(reg1->smin_value, reg2->smin_value);
+ }
+ break;
case BPF_JSLT:
- {
if (is_jmp32) {
- s32 false_smin = opcode == BPF_JSLT ? sval32 : sval32 + 1;
- s32 true_smax = opcode == BPF_JSLT ? sval32 - 1 : sval32;
-
- false_reg->s32_min_value = max(false_reg->s32_min_value, false_smin);
- true_reg->s32_max_value = min(true_reg->s32_max_value, true_smax);
+ reg1->s32_max_value = min(reg1->s32_max_value, reg2->s32_max_value - 1);
+ reg2->s32_min_value = max(reg1->s32_min_value + 1, reg2->s32_min_value);
} else {
- s64 false_smin = opcode == BPF_JSLT ? sval : sval + 1;
- s64 true_smax = opcode == BPF_JSLT ? sval - 1 : sval;
-
- false_reg->smin_value = max(false_reg->smin_value, false_smin);
- true_reg->smax_value = min(true_reg->smax_value, true_smax);
+ reg1->smax_value = min(reg1->smax_value, reg2->smax_value - 1);
+ reg2->smin_value = max(reg1->smin_value + 1, reg2->smin_value);
}
break;
- }
+ case BPF_JGE:
+ case BPF_JGT:
+ case BPF_JSGE:
+ case BPF_JSGT:
+ /* just reuse LE/LT logic above */
+ opcode = flip_opcode(opcode);
+ swap(reg1, reg2);
+ goto again;
default:
return;
}
-
- if (is_jmp32) {
- false_reg->var_off = tnum_or(tnum_clear_subreg(false_64off),
- tnum_subreg(false_32off));
- true_reg->var_off = tnum_or(tnum_clear_subreg(true_64off),
- tnum_subreg(true_32off));
- __reg_combine_32_into_64(false_reg);
- __reg_combine_32_into_64(true_reg);
- } else {
- false_reg->var_off = false_64off;
- true_reg->var_off = true_64off;
- __reg_combine_64_into_32(false_reg);
- __reg_combine_64_into_32(true_reg);
- }
}
-/* Same as above, but for the case that dst_reg holds a constant and src_reg is
- * the variable reg.
+/* Adjusts the register min/max values in the case that the dst_reg and
+ * src_reg are both SCALAR_VALUE registers (or we are simply doing a BPF_K
+ * check, in which case we havea fake SCALAR_VALUE representing insn->imm).
+ * Technically we can do similar adjustments for pointers to the same object,
+ * but we don't support that right now.
*/
-static void reg_set_min_max_inv(struct bpf_reg_state *true_reg,
- struct bpf_reg_state *false_reg,
- u64 val, u32 val32,
- u8 opcode, bool is_jmp32)
+static int reg_set_min_max(struct bpf_verifier_env *env,
+ struct bpf_reg_state *true_reg1,
+ struct bpf_reg_state *true_reg2,
+ struct bpf_reg_state *false_reg1,
+ struct bpf_reg_state *false_reg2,
+ u8 opcode, bool is_jmp32)
{
- opcode = flip_opcode(opcode);
- /* This uses zero as "not present in table"; luckily the zero opcode,
- * BPF_JA, can't get here.
+ int err;
+
+ /* If either register is a pointer, we can't learn anything about its
+ * variable offset from the compare (unless they were a pointer into
+ * the same object, but we don't bother with that).
*/
- if (opcode)
- reg_set_min_max(true_reg, false_reg, val, val32, opcode, is_jmp32);
-}
-
-/* Regs are known to be equal, so intersect their min/max/var_off */
-static void __reg_combine_min_max(struct bpf_reg_state *src_reg,
- struct bpf_reg_state *dst_reg)
-{
- src_reg->umin_value = dst_reg->umin_value = max(src_reg->umin_value,
- dst_reg->umin_value);
- src_reg->umax_value = dst_reg->umax_value = min(src_reg->umax_value,
- dst_reg->umax_value);
- src_reg->smin_value = dst_reg->smin_value = max(src_reg->smin_value,
- dst_reg->smin_value);
- src_reg->smax_value = dst_reg->smax_value = min(src_reg->smax_value,
- dst_reg->smax_value);
- src_reg->var_off = dst_reg->var_off = tnum_intersect(src_reg->var_off,
- dst_reg->var_off);
- reg_bounds_sync(src_reg);
- reg_bounds_sync(dst_reg);
-}
+ if (false_reg1->type != SCALAR_VALUE || false_reg2->type != SCALAR_VALUE)
+ return 0;
-static void reg_combine_min_max(struct bpf_reg_state *true_src,
- struct bpf_reg_state *true_dst,
- struct bpf_reg_state *false_src,
- struct bpf_reg_state *false_dst,
- u8 opcode)
-{
- switch (opcode) {
- case BPF_JEQ:
- __reg_combine_min_max(true_src, true_dst);
- break;
- case BPF_JNE:
- __reg_combine_min_max(false_src, false_dst);
- break;
- }
+ /* fallthrough (FALSE) branch */
+ regs_refine_cond_op(false_reg1, false_reg2, rev_opcode(opcode), is_jmp32);
+ reg_bounds_sync(false_reg1);
+ reg_bounds_sync(false_reg2);
+
+ /* jump (TRUE) branch */
+ regs_refine_cond_op(true_reg1, true_reg2, opcode, is_jmp32);
+ reg_bounds_sync(true_reg1);
+ reg_bounds_sync(true_reg2);
+
+ err = reg_bounds_sanity_check(env, true_reg1, "true_reg1");
+ err = err ?: reg_bounds_sanity_check(env, true_reg2, "true_reg2");
+ err = err ?: reg_bounds_sanity_check(env, false_reg1, "false_reg1");
+ err = err ?: reg_bounds_sanity_check(env, false_reg2, "false_reg2");
+ return err;
}
static void mark_ptr_or_null_reg(struct bpf_func_state *state,
@@ -14839,6 +14796,7 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
struct bpf_reg_state *regs = this_branch->frame[this_branch->curframe]->regs;
struct bpf_reg_state *dst_reg, *other_branch_regs, *src_reg = NULL;
struct bpf_reg_state *eq_branch_regs;
+ struct bpf_reg_state fake_reg = {};
u8 opcode = BPF_OP(insn->code);
bool is_jmp32;
int pred = -1;
@@ -14879,42 +14837,13 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
verbose(env, "BPF_JMP/JMP32 uses reserved fields\n");
return -EINVAL;
}
+ src_reg = &fake_reg;
+ src_reg->type = SCALAR_VALUE;
+ __mark_reg_known(src_reg, insn->imm);
}
is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
-
- if (BPF_SRC(insn->code) == BPF_K) {
- pred = is_branch_taken(dst_reg, insn->imm, opcode, is_jmp32);
- } else if (src_reg->type == SCALAR_VALUE &&
- is_jmp32 && tnum_is_const(tnum_subreg(src_reg->var_off))) {
- pred = is_branch_taken(dst_reg,
- tnum_subreg(src_reg->var_off).value,
- opcode,
- is_jmp32);
- } else if (src_reg->type == SCALAR_VALUE &&
- !is_jmp32 && tnum_is_const(src_reg->var_off)) {
- pred = is_branch_taken(dst_reg,
- src_reg->var_off.value,
- opcode,
- is_jmp32);
- } else if (dst_reg->type == SCALAR_VALUE &&
- is_jmp32 && tnum_is_const(tnum_subreg(dst_reg->var_off))) {
- pred = is_branch_taken(src_reg,
- tnum_subreg(dst_reg->var_off).value,
- flip_opcode(opcode),
- is_jmp32);
- } else if (dst_reg->type == SCALAR_VALUE &&
- !is_jmp32 && tnum_is_const(dst_reg->var_off)) {
- pred = is_branch_taken(src_reg,
- dst_reg->var_off.value,
- flip_opcode(opcode),
- is_jmp32);
- } else if (reg_is_pkt_pointer_any(dst_reg) &&
- reg_is_pkt_pointer_any(src_reg) &&
- !is_jmp32) {
- pred = is_pkt_ptr_branch_taken(dst_reg, src_reg, opcode);
- }
-
+ pred = is_branch_taken(dst_reg, src_reg, opcode, is_jmp32);
if (pred >= 0) {
/* If we get here with a dst_reg pointer type it is because
* above is_branch_taken() special cased the 0 comparison.
@@ -14962,53 +14891,27 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
return -EFAULT;
other_branch_regs = other_branch->frame[other_branch->curframe]->regs;
- /* detect if we are comparing against a constant value so we can adjust
- * our min/max values for our dst register.
- * this is only legit if both are scalars (or pointers to the same
- * object, I suppose, see the PTR_MAYBE_NULL related if block below),
- * because otherwise the different base pointers mean the offsets aren't
- * comparable.
- */
if (BPF_SRC(insn->code) == BPF_X) {
- struct bpf_reg_state *src_reg = &regs[insn->src_reg];
-
- if (dst_reg->type == SCALAR_VALUE &&
- src_reg->type == SCALAR_VALUE) {
- if (tnum_is_const(src_reg->var_off) ||
- (is_jmp32 &&
- tnum_is_const(tnum_subreg(src_reg->var_off))))
- reg_set_min_max(&other_branch_regs[insn->dst_reg],
- dst_reg,
- src_reg->var_off.value,
- tnum_subreg(src_reg->var_off).value,
- opcode, is_jmp32);
- else if (tnum_is_const(dst_reg->var_off) ||
- (is_jmp32 &&
- tnum_is_const(tnum_subreg(dst_reg->var_off))))
- reg_set_min_max_inv(&other_branch_regs[insn->src_reg],
- src_reg,
- dst_reg->var_off.value,
- tnum_subreg(dst_reg->var_off).value,
- opcode, is_jmp32);
- else if (!is_jmp32 &&
- (opcode == BPF_JEQ || opcode == BPF_JNE))
- /* Comparing for equality, we can combine knowledge */
- reg_combine_min_max(&other_branch_regs[insn->src_reg],
- &other_branch_regs[insn->dst_reg],
- src_reg, dst_reg, opcode);
- if (src_reg->id &&
- !WARN_ON_ONCE(src_reg->id != other_branch_regs[insn->src_reg].id)) {
- find_equal_scalars(this_branch, src_reg);
- find_equal_scalars(other_branch, &other_branch_regs[insn->src_reg]);
- }
-
- }
- } else if (dst_reg->type == SCALAR_VALUE) {
- reg_set_min_max(&other_branch_regs[insn->dst_reg],
- dst_reg, insn->imm, (u32)insn->imm,
- opcode, is_jmp32);
+ err = reg_set_min_max(env,
+ &other_branch_regs[insn->dst_reg],
+ &other_branch_regs[insn->src_reg],
+ dst_reg, src_reg, opcode, is_jmp32);
+ } else /* BPF_SRC(insn->code) == BPF_K */ {
+ err = reg_set_min_max(env,
+ &other_branch_regs[insn->dst_reg],
+ src_reg /* fake one */,
+ dst_reg, src_reg /* same fake one */,
+ opcode, is_jmp32);
}
+ if (err)
+ return err;
+ if (BPF_SRC(insn->code) == BPF_X &&
+ src_reg->type == SCALAR_VALUE && src_reg->id &&
+ !WARN_ON_ONCE(src_reg->id != other_branch_regs[insn->src_reg].id)) {
+ find_equal_scalars(this_branch, src_reg);
+ find_equal_scalars(other_branch, &other_branch_regs[insn->src_reg]);
+ }
if (dst_reg->type == SCALAR_VALUE && dst_reg->id &&
!WARN_ON_ONCE(dst_reg->id != other_branch_regs[insn->dst_reg].id)) {
find_equal_scalars(this_branch, dst_reg);
@@ -15280,12 +15183,13 @@ static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn)
return 0;
}
-static int check_return_code(struct bpf_verifier_env *env, int regno)
+static int check_return_code(struct bpf_verifier_env *env, int regno, const char *reg_name)
{
+ const char *exit_ctx = "At program exit";
struct tnum enforce_attach_type_range = tnum_unknown;
const struct bpf_prog *prog = env->prog;
struct bpf_reg_state *reg;
- struct tnum range = tnum_range(0, 1), const_0 = tnum_const(0);
+ struct bpf_retval_range range = retval_range(0, 1);
enum bpf_prog_type prog_type = resolve_prog_type(env->prog);
int err;
struct bpf_func_state *frame = env->cur_state->frame[0];
@@ -15327,17 +15231,9 @@ static int check_return_code(struct bpf_verifier_env *env, int regno)
if (frame->in_async_callback_fn) {
/* enforce return zero from async callbacks like timer */
- if (reg->type != SCALAR_VALUE) {
- verbose(env, "In async callback the register R%d is not a known value (%s)\n",
- regno, reg_type_str(env, reg->type));
- return -EINVAL;
- }
-
- if (!tnum_in(const_0, reg->var_off)) {
- verbose_invalid_scalar(env, reg, &const_0, "async callback", "R0");
- return -EINVAL;
- }
- return 0;
+ exit_ctx = "At async callback return";
+ range = retval_range(0, 0);
+ goto enforce_retval;
}
if (is_subprog && !frame->in_exception_callback_fn) {
@@ -15360,14 +15256,14 @@ static int check_return_code(struct bpf_verifier_env *env, int regno)
env->prog->expected_attach_type == BPF_CGROUP_INET4_GETSOCKNAME ||
env->prog->expected_attach_type == BPF_CGROUP_INET6_GETSOCKNAME ||
env->prog->expected_attach_type == BPF_CGROUP_UNIX_GETSOCKNAME)
- range = tnum_range(1, 1);
+ range = retval_range(1, 1);
if (env->prog->expected_attach_type == BPF_CGROUP_INET4_BIND ||
env->prog->expected_attach_type == BPF_CGROUP_INET6_BIND)
- range = tnum_range(0, 3);
+ range = retval_range(0, 3);
break;
case BPF_PROG_TYPE_CGROUP_SKB:
if (env->prog->expected_attach_type == BPF_CGROUP_INET_EGRESS) {
- range = tnum_range(0, 3);
+ range = retval_range(0, 3);
enforce_attach_type_range = tnum_range(2, 3);
}
break;
@@ -15380,13 +15276,13 @@ static int check_return_code(struct bpf_verifier_env *env, int regno)
case BPF_PROG_TYPE_RAW_TRACEPOINT:
if (!env->prog->aux->attach_btf_id)
return 0;
- range = tnum_const(0);
+ range = retval_range(0, 0);
break;
case BPF_PROG_TYPE_TRACING:
switch (env->prog->expected_attach_type) {
case BPF_TRACE_FENTRY:
case BPF_TRACE_FEXIT:
- range = tnum_const(0);
+ range = retval_range(0, 0);
break;
case BPF_TRACE_RAW_TP:
case BPF_MODIFY_RETURN:
@@ -15398,7 +15294,7 @@ static int check_return_code(struct bpf_verifier_env *env, int regno)
}
break;
case BPF_PROG_TYPE_SK_LOOKUP:
- range = tnum_range(SK_DROP, SK_PASS);
+ range = retval_range(SK_DROP, SK_PASS);
break;
case BPF_PROG_TYPE_LSM:
@@ -15412,12 +15308,12 @@ static int check_return_code(struct bpf_verifier_env *env, int regno)
/* Make sure programs that attach to void
* hooks don't try to modify return value.
*/
- range = tnum_range(1, 1);
+ range = retval_range(1, 1);
}
break;
case BPF_PROG_TYPE_NETFILTER:
- range = tnum_range(NF_DROP, NF_ACCEPT);
+ range = retval_range(NF_DROP, NF_ACCEPT);
break;
case BPF_PROG_TYPE_EXT:
/* freplace program can return anything as its return value
@@ -15427,15 +15323,21 @@ static int check_return_code(struct bpf_verifier_env *env, int regno)
return 0;
}
+enforce_retval:
if (reg->type != SCALAR_VALUE) {
- verbose(env, "At program exit the register R%d is not a known value (%s)\n",
- regno, reg_type_str(env, reg->type));
+ verbose(env, "%s the register R%d is not a known value (%s)\n",
+ exit_ctx, regno, reg_type_str(env, reg->type));
return -EINVAL;
}
- if (!tnum_in(range, reg->var_off)) {
- verbose_invalid_scalar(env, reg, &range, "program exit", "R0");
- if (prog->expected_attach_type == BPF_LSM_CGROUP &&
+ err = mark_chain_precision(env, regno);
+ if (err)
+ return err;
+
+ if (!retval_range_within(range, reg)) {
+ verbose_invalid_scalar(env, reg, range, exit_ctx, reg_name);
+ if (!is_subprog &&
+ prog->expected_attach_type == BPF_LSM_CGROUP &&
prog_type == BPF_PROG_TYPE_LSM &&
!prog->aux->attach_func_proto->type)
verbose(env, "Note, BPF_LSM_CGROUP that attach to void LSM hooks can't modify return value!\n");
@@ -17200,7 +17102,8 @@ hit:
* the precision needs to be propagated back in
* the current state.
*/
- err = err ? : push_jmp_history(env, cur);
+ if (is_jmp_point(env, env->insn_idx))
+ err = err ? : push_jmp_history(env, cur, 0);
err = err ? : propagate_precision(env, &sl->state);
if (err)
return err;
@@ -17425,6 +17328,9 @@ static int do_check(struct bpf_verifier_env *env)
u8 class;
int err;
+ /* reset current history entry on each new instruction */
+ env->cur_hist_ent = NULL;
+
env->prev_insn_idx = prev_insn_idx;
if (env->insn_idx >= insn_cnt) {
verbose(env, "invalid insn idx %d insn_cnt %d\n",
@@ -17464,7 +17370,7 @@ static int do_check(struct bpf_verifier_env *env)
}
if (is_jmp_point(env, env->insn_idx)) {
- err = push_jmp_history(env, state);
+ err = push_jmp_history(env, state, 0);
if (err)
return err;
}
@@ -17541,10 +17447,8 @@ static int do_check(struct bpf_verifier_env *env)
insn->off, BPF_SIZE(insn->code),
BPF_READ, insn->dst_reg, false,
BPF_MODE(insn->code) == BPF_MEMSX);
- if (err)
- return err;
-
- err = save_aux_ptr_type(env, src_reg_type, true);
+ err = err ?: save_aux_ptr_type(env, src_reg_type, true);
+ err = err ?: reg_bounds_sanity_check(env, &regs[insn->dst_reg], "ldx");
if (err)
return err;
} else if (class == BPF_STX) {
@@ -17720,7 +17624,7 @@ process_bpf_exit_full:
continue;
}
- err = check_return_code(env, BPF_REG_0);
+ err = check_return_code(env, BPF_REG_0, "R0");
if (err)
return err;
process_bpf_exit:
@@ -18181,10 +18085,12 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
return -E2BIG;
}
+ if (env->prog->aux->sleepable)
+ atomic64_inc(&map->sleepable_refcnt);
/* hold the map. If the program is rejected by verifier,
* the map will be released by release_maps() or it
* will be used by the valid program until it's unloaded
- * and all maps are released in free_used_maps()
+ * and all maps are released in bpf_free_used_maps()
*/
bpf_map_inc(map);
@@ -19401,9 +19307,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
env->exception_callback_subprog = env->subprog_cnt - 1;
/* Don't update insn_cnt, as add_hidden_subprog always appends insns */
- env->subprog_info[env->exception_callback_subprog].is_cb = true;
- env->subprog_info[env->exception_callback_subprog].is_async_cb = true;
- env->subprog_info[env->exception_callback_subprog].is_exception_cb = true;
+ mark_subprog_exc_cb(env, env->exception_callback_subprog);
}
for (i = 0; i < insn_cnt; i++, insn++) {
@@ -20103,9 +20007,10 @@ static void free_states(struct bpf_verifier_env *env)
}
}
-static int do_check_common(struct bpf_verifier_env *env, int subprog, bool is_ex_cb)
+static int do_check_common(struct bpf_verifier_env *env, int subprog)
{
bool pop_log = !(env->log.level & BPF_LOG_LEVEL2);
+ struct bpf_subprog_info *sub = subprog_info(env, subprog);
struct bpf_verifier_state *state;
struct bpf_reg_state *regs;
int ret, i;
@@ -20132,46 +20037,71 @@ static int do_check_common(struct bpf_verifier_env *env, int subprog, bool is_ex
state->first_insn_idx = env->subprog_info[subprog].start;
state->last_insn_idx = -1;
+
regs = state->frame[state->curframe]->regs;
if (subprog || env->prog->type == BPF_PROG_TYPE_EXT) {
- ret = btf_prepare_func_args(env, subprog, regs, is_ex_cb);
+ const char *sub_name = subprog_name(env, subprog);
+ struct bpf_subprog_arg_info *arg;
+ struct bpf_reg_state *reg;
+
+ verbose(env, "Validating %s() func#%d...\n", sub_name, subprog);
+ ret = btf_prepare_func_args(env, subprog);
if (ret)
goto out;
- for (i = BPF_REG_1; i <= BPF_REG_5; i++) {
- if (regs[i].type == PTR_TO_CTX)
+
+ if (subprog_is_exc_cb(env, subprog)) {
+ state->frame[0]->in_exception_callback_fn = true;
+ /* We have already ensured that the callback returns an integer, just
+ * like all global subprogs. We need to determine it only has a single
+ * scalar argument.
+ */
+ if (sub->arg_cnt != 1 || sub->args[0].arg_type != ARG_ANYTHING) {
+ verbose(env, "exception cb only supports single integer argument\n");
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+ for (i = BPF_REG_1; i <= sub->arg_cnt; i++) {
+ arg = &sub->args[i - BPF_REG_1];
+ reg = &regs[i];
+
+ if (arg->arg_type == ARG_PTR_TO_CTX) {
+ reg->type = PTR_TO_CTX;
mark_reg_known_zero(env, regs, i);
- else if (regs[i].type == SCALAR_VALUE)
+ } else if (arg->arg_type == ARG_ANYTHING) {
+ reg->type = SCALAR_VALUE;
mark_reg_unknown(env, regs, i);
- else if (base_type(regs[i].type) == PTR_TO_MEM) {
- const u32 mem_size = regs[i].mem_size;
-
+ } else if (arg->arg_type == (ARG_PTR_TO_DYNPTR | MEM_RDONLY)) {
+ /* assume unspecial LOCAL dynptr type */
+ __mark_dynptr_reg(reg, BPF_DYNPTR_TYPE_LOCAL, true, ++env->id_gen);
+ } else if (base_type(arg->arg_type) == ARG_PTR_TO_MEM) {
+ reg->type = PTR_TO_MEM;
+ if (arg->arg_type & PTR_MAYBE_NULL)
+ reg->type |= PTR_MAYBE_NULL;
mark_reg_known_zero(env, regs, i);
- regs[i].mem_size = mem_size;
- regs[i].id = ++env->id_gen;
+ reg->mem_size = arg->mem_size;
+ reg->id = ++env->id_gen;
+ } else {
+ WARN_ONCE(1, "BUG: unhandled arg#%d type %d\n",
+ i - BPF_REG_1, arg->arg_type);
+ ret = -EFAULT;
+ goto out;
}
}
- if (is_ex_cb) {
- state->frame[0]->in_exception_callback_fn = true;
- env->subprog_info[subprog].is_cb = true;
- env->subprog_info[subprog].is_async_cb = true;
- env->subprog_info[subprog].is_exception_cb = true;
- }
} else {
+ /* if main BPF program has associated BTF info, validate that
+ * it's matching expected signature, and otherwise mark BTF
+ * info for main program as unreliable
+ */
+ if (env->prog->aux->func_info_aux) {
+ ret = btf_prepare_func_args(env, 0);
+ if (ret || sub->arg_cnt != 1 || sub->args[0].arg_type != ARG_PTR_TO_CTX)
+ env->prog->aux->func_info_aux[0].unreliable = true;
+ }
+
/* 1st arg to a function */
regs[BPF_REG_1].type = PTR_TO_CTX;
mark_reg_known_zero(env, regs, BPF_REG_1);
- ret = btf_check_subprog_arg_match(env, subprog, regs);
- if (ret == -EFAULT)
- /* unlikely verifier bug. abort.
- * ret == 0 and ret < 0 are sadly acceptable for
- * main() function due to backward compatibility.
- * Like socket filter program may be written as:
- * int bpf_prog(struct pt_regs *ctx)
- * and never dereference that ctx in the program.
- * 'struct pt_regs' is a type mismatch for socket
- * filter that should be using 'struct __sk_buff'.
- */
- goto out;
}
ret = do_check(env);
@@ -20190,8 +20120,11 @@ out:
return ret;
}
-/* Verify all global functions in a BPF program one by one based on their BTF.
- * All global functions must pass verification. Otherwise the whole program is rejected.
+/* Lazily verify all global functions based on their BTF, if they are called
+ * from main BPF program or any of subprograms transitively.
+ * BPF global subprogs called from dead code are not validated.
+ * All callable global functions must pass verification.
+ * Otherwise the whole program is rejected.
* Consider:
* int bar(int);
* int foo(int f)
@@ -20210,25 +20143,50 @@ out:
static int do_check_subprogs(struct bpf_verifier_env *env)
{
struct bpf_prog_aux *aux = env->prog->aux;
- int i, ret;
+ struct bpf_func_info_aux *sub_aux;
+ int i, ret, new_cnt;
if (!aux->func_info)
return 0;
+ /* exception callback is presumed to be always called */
+ if (env->exception_callback_subprog)
+ subprog_aux(env, env->exception_callback_subprog)->called = true;
+
+again:
+ new_cnt = 0;
for (i = 1; i < env->subprog_cnt; i++) {
- if (aux->func_info_aux[i].linkage != BTF_FUNC_GLOBAL)
+ if (!subprog_is_global(env, i))
+ continue;
+
+ sub_aux = subprog_aux(env, i);
+ if (!sub_aux->called || sub_aux->verified)
continue;
+
env->insn_idx = env->subprog_info[i].start;
WARN_ON_ONCE(env->insn_idx == 0);
- ret = do_check_common(env, i, env->exception_callback_subprog == i);
+ ret = do_check_common(env, i);
if (ret) {
return ret;
} else if (env->log.level & BPF_LOG_LEVEL) {
- verbose(env,
- "Func#%d is safe for any args that match its prototype\n",
- i);
+ verbose(env, "Func#%d ('%s') is safe for any args that match its prototype\n",
+ i, subprog_name(env, i));
}
+
+ /* We verified new global subprog, it might have called some
+ * more global subprogs that we haven't verified yet, so we
+ * need to do another pass over subprogs to verify those.
+ */
+ sub_aux->verified = true;
+ new_cnt++;
}
+
+ /* We can't loop forever as we verify at least one global subprog on
+ * each pass.
+ */
+ if (new_cnt)
+ goto again;
+
return 0;
}
@@ -20237,7 +20195,7 @@ static int do_check_main(struct bpf_verifier_env *env)
int ret;
env->insn_idx = 0;
- ret = do_check_common(env, 0, false);
+ ret = do_check_common(env, 0);
if (!ret)
env->prog->aux->stack_depth = env->subprog_info[0].stack_depth;
return ret;
@@ -20359,6 +20317,7 @@ int bpf_check_attach_target(struct bpf_verifier_log *log,
struct bpf_attach_target_info *tgt_info)
{
bool prog_extension = prog->type == BPF_PROG_TYPE_EXT;
+ bool prog_tracing = prog->type == BPF_PROG_TYPE_TRACING;
const char prefix[] = "btf_trace_";
int ret = 0, subprog = -1, i;
const struct btf_type *t;
@@ -20429,10 +20388,21 @@ int bpf_check_attach_target(struct bpf_verifier_log *log,
bpf_log(log, "Can attach to only JITed progs\n");
return -EINVAL;
}
- if (tgt_prog->type == prog->type) {
- /* Cannot fentry/fexit another fentry/fexit program.
- * Cannot attach program extension to another extension.
- * It's ok to attach fentry/fexit to extension program.
+ if (prog_tracing) {
+ if (aux->attach_tracing_prog) {
+ /*
+ * Target program is an fentry/fexit which is already attached
+ * to another tracing program. More levels of nesting
+ * attachment are not allowed.
+ */
+ bpf_log(log, "Cannot nest tracing program attach more than once\n");
+ return -EINVAL;
+ }
+ } else if (tgt_prog->type == prog->type) {
+ /*
+ * To avoid potential call chain cycles, prevent attaching of a
+ * program extension to another extension. It's ok to attach
+ * fentry/fexit to extension program.
*/
bpf_log(log, "Cannot recursively attach\n");
return -EINVAL;
@@ -20445,16 +20415,15 @@ int bpf_check_attach_target(struct bpf_verifier_log *log,
* except fentry/fexit. The reason is the following.
* The fentry/fexit programs are used for performance
* analysis, stats and can be attached to any program
- * type except themselves. When extension program is
- * replacing XDP function it is necessary to allow
- * performance analysis of all functions. Both original
- * XDP program and its program extension. Hence
- * attaching fentry/fexit to BPF_PROG_TYPE_EXT is
- * allowed. If extending of fentry/fexit was allowed it
- * would be possible to create long call chain
- * fentry->extension->fentry->extension beyond
- * reasonable stack size. Hence extending fentry is not
- * allowed.
+ * type. When extension program is replacing XDP function
+ * it is necessary to allow performance analysis of all
+ * functions. Both original XDP program and its program
+ * extension. Hence attaching fentry/fexit to
+ * BPF_PROG_TYPE_EXT is allowed. If extending of
+ * fentry/fexit was allowed it would be possible to create
+ * long call chain fentry->extension->fentry->extension
+ * beyond reasonable stack size. Hence extending fentry
+ * is not allowed.
*/
bpf_log(log, "Cannot extend fentry/fexit\n");
return -EINVAL;
@@ -20831,6 +20800,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
if (is_priv)
env->test_state_freq = attr->prog_flags & BPF_F_TEST_STATE_FREQ;
+ env->test_reg_invariants = attr->prog_flags & BPF_F_TEST_REG_INVARIANTS;
env->explored_states = kvcalloc(state_htab_size(env),
sizeof(struct bpf_verifier_state_list *),
@@ -20873,8 +20843,8 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
if (ret < 0)
goto skip_full_check;
- ret = do_check_subprogs(env);
- ret = ret ?: do_check_main(env);
+ ret = do_check_main(env);
+ ret = ret ?: do_check_subprogs(env);
if (ret == 0 && bpf_prog_is_offloaded(env->prog->aux))
ret = bpf_prog_offload_finalize(env);