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2020-08-01bpf: Add support for forced LINK_DETACH commandAndrii Nakryiko
Add LINK_DETACH command to force-detach bpf_link without destroying it. It has the same behavior as auto-detaching of bpf_link due to cgroup dying for bpf_cgroup_link or net_device being destroyed for bpf_xdp_link. In such case, bpf_link is still a valid kernel object, but is defuncts and doesn't hold BPF program attached to corresponding BPF hook. This functionality allows users with enough access rights to manually force-detach attached bpf_link without killing respective owner process. This patch implements LINK_DETACH for cgroup, xdp, and netns links, mostly re-using existing link release handling code. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200731182830.286260-2-andriin@fb.com
2020-07-31bpf: Add missing newline characters in verifier error messagesYonghong Song
Newline characters are added in two verifier error messages, refactored in Commit afbf21dce668 ("bpf: Support readonly/readwrite buffers in verifier"). This way, they do not mix with messages afterwards. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200728221801.1090349-1-yhs@fb.com
2020-07-29bpf: Fix build without CONFIG_NET when using BPF XDP linkAndrii Nakryiko
Entire net/core subsystem is not built without CONFIG_NET. linux/netdevice.h just assumes that it's always there, so the easiest way to fix this is to conditionally compile out bpf_xdp_link_attach() use in bpf/syscall.c. Fixes: aa8d3a716b59 ("bpf, xdp: Add bpf_link-based XDP attachment API") Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200728190527.110830-1-andriin@fb.com
2020-07-28bpf: Fix swapped arguments in calls to check_buffer_accessColin Ian King
There are a couple of arguments of the boolean flag zero_size_allowed and the char pointer buf_info when calling to function check_buffer_access that are swapped by mistake. Fix these by swapping them to correct the argument ordering. Fixes: afbf21dce668 ("bpf: Support readonly/readwrite buffers in verifier") Addresses-Coverity: ("Array compared to 0") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200727175411.155179-1-colin.king@canonical.com
2020-07-25bpf, xdp: Add bpf_link-based XDP attachment APIAndrii Nakryiko
Add bpf_link-based API (bpf_xdp_link) to attach BPF XDP program through BPF_LINK_CREATE command. bpf_xdp_link is mutually exclusive with direct BPF program attachment, previous BPF program should be detached prior to attempting to create a new bpf_xdp_link attachment (for a given XDP mode). Once BPF link is attached, it can't be replaced by other BPF program attachment or link attachment. It will be detached only when the last BPF link FD is closed. bpf_xdp_link will be auto-detached when net_device is shutdown, similarly to how other BPF links behave (cgroup, flow_dissector). At that point bpf_link will become defunct, but won't be destroyed until last FD is closed. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200722064603.3350758-5-andriin@fb.com
2020-07-25bpf: Fix build on architectures with special bpf_user_pt_regs_tSong Liu
Architectures like s390, powerpc, arm64, riscv have speical definition of bpf_user_pt_regs_t. So we need to cast the pointer before passing it to bpf_get_stack(). This is similar to bpf_get_stack_tp(). Fixes: 03d42fd2d83f ("bpf: Separate bpf_get_[stack|stackid] for perf events BPF") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200724200503.3629591-1-songliubraving@fb.com
2020-07-25bpf/local_storage: Fix build without CONFIG_CGROUPYiFei Zhu
local_storage.o has its compile guard as CONFIG_BPF_SYSCALL, which does not imply that CONFIG_CGROUP is on. Including cgroup-internal.h when CONFIG_CGROUP is off cause a compilation failure. Fixes: f67cfc233706 ("bpf: Make cgroup storages shared between programs on the same cgroup") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: YiFei Zhu <zhuyifei@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200724211753.902969-1-zhuyifei1999@gmail.com
2020-07-25bpf: Make cgroup storages shared between programs on the same cgroupYiFei Zhu
This change comes in several parts: One, the restriction that the CGROUP_STORAGE map can only be used by one program is removed. This results in the removal of the field 'aux' in struct bpf_cgroup_storage_map, and removal of relevant code associated with the field, and removal of now-noop functions bpf_free_cgroup_storage and bpf_cgroup_storage_release. Second, we permit a key of type u64 as the key to the map. Providing such a key type indicates that the map should ignore attach type when comparing map keys. However, for simplicity newly linked storage will still have the attach type at link time in its key struct. cgroup_storage_check_btf is adapted to accept u64 as the type of the key. Third, because the storages are now shared, the storages cannot be unconditionally freed on program detach. There could be two ways to solve this issue: * A. Reference count the usage of the storages, and free when the last program is detached. * B. Free only when the storage is impossible to be referred to again, i.e. when either the cgroup_bpf it is attached to, or the map itself, is freed. Option A has the side effect that, when the user detach and reattach a program, whether the program gets a fresh storage depends on whether there is another program attached using that storage. This could trigger races if the user is multi-threaded, and since nondeterminism in data races is evil, go with option B. The both the map and the cgroup_bpf now tracks their associated storages, and the storage unlink and free are removed from cgroup_bpf_detach and added to cgroup_bpf_release and cgroup_storage_map_free. The latter also new holds the cgroup_mutex to prevent any races with the former. Fourth, on attach, we reuse the old storage if the key already exists in the map, via cgroup_storage_lookup. If the storage does not exist yet, we create a new one, and publish it at the last step in the attach process. This does not create a race condition because for the whole attach the cgroup_mutex is held. We keep track of an array of new storages that was allocated and if the process fails only the new storages would get freed. Signed-off-by: YiFei Zhu <zhuyifei@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/d5401c6106728a00890401190db40020a1f84ff1.1595565795.git.zhuyifei@google.com
2020-07-25bpf: Fail PERF_EVENT_IOC_SET_BPF when bpf_get_[stack|stackid] cannot workSong Liu
bpf_get_[stack|stackid] on perf_events with precise_ip uses callchain attached to perf_sample_data. If this callchain is not presented, do not allow attaching BPF program that calls bpf_get_[stack|stackid] to this event. In the error case, -EPROTO is returned so that libbpf can identify this error and print proper hint message. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723180648.1429892-3-songliubraving@fb.com
2020-07-25bpf: Separate bpf_get_[stack|stackid] for perf events BPFSong Liu
Calling get_perf_callchain() on perf_events from PEBS entries may cause unwinder errors. To fix this issue, the callchain is fetched early. Such perf_events are marked with __PERF_SAMPLE_CALLCHAIN_EARLY. Similarly, calling bpf_get_[stack|stackid] on perf_events from PEBS may also cause unwinder errors. To fix this, add separate version of these two helpers, bpf_get_[stack|stackid]_pe. These two hepers use callchain in bpf_perf_event_data_kern->data->callchain. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723180648.1429892-2-songliubraving@fb.com
2020-07-25bpf: Implement bpf iterator for array mapsYonghong Song
The bpf iterators for array and percpu array are implemented. Similar to hash maps, for percpu array map, bpf program will receive values from all cpus. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184115.590532-1-yhs@fb.com
2020-07-25bpf: Implement bpf iterator for hash mapsYonghong Song
The bpf iterators for hash, percpu hash, lru hash and lru percpu hash are implemented. During link time, bpf_iter_reg->check_target() will check map type and ensure the program access key/value region is within the map defined key/value size limit. For percpu hash and lru hash maps, the bpf program will receive values for all cpus. The map element bpf iterator infrastructure will prepare value properly before passing the value pointer to the bpf program. This patch set supports readonly map keys and read/write map values. It does not support deleting map elements, e.g., from hash tables. If there is a user case for this, the following mechanism can be used to support map deletion for hashtab, etc. - permit a new bpf program return value, e.g., 2, to let bpf iterator know the map element should be removed. - since bucket lock is taken, the map element will be queued. - once bucket lock is released after all elements under this bucket are traversed, all to-be-deleted map elements can be deleted. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184114.590470-1-yhs@fb.com
2020-07-25bpf: Implement bpf iterator for map elementsYonghong Song
The bpf iterator for map elements are implemented. The bpf program will receive four parameters: bpf_iter_meta *meta: the meta data bpf_map *map: the bpf_map whose elements are traversed void *key: the key of one element void *value: the value of the same element Here, meta and map pointers are always valid, and key has register type PTR_TO_RDONLY_BUF_OR_NULL and value has register type PTR_TO_RDWR_BUF_OR_NULL. The kernel will track the access range of key and value during verification time. Later, these values will be compared against the values in the actual map to ensure all accesses are within range. A new field iter_seq_info is added to bpf_map_ops which is used to add map type specific information, i.e., seq_ops, init/fini seq_file func and seq_file private data size. Subsequent patches will have actual implementation for bpf_map_ops->iter_seq_info. In user space, BPF_ITER_LINK_MAP_FD needs to be specified in prog attr->link_create.flags, which indicates that attr->link_create.target_fd is a map_fd. The reason for such an explicit flag is for possible future cases where one bpf iterator may allow more than one possible customization, e.g., pid and cgroup id for task_file. Current kernel internal implementation only allows the target to register at most one required bpf_iter_link_info. To support the above case, optional bpf_iter_link_info's are needed, the target can be extended to register such link infos, and user provided link_info needs to match one of target supported ones. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184112.590360-1-yhs@fb.com
2020-07-25bpf: Support readonly/readwrite buffers in verifierYonghong Song
Readonly and readwrite buffer register states are introduced. Totally four states, PTR_TO_RDONLY_BUF[_OR_NULL] and PTR_TO_RDWR_BUF[_OR_NULL] are supported. As suggested by their respective names, PTR_TO_RDONLY_BUF[_OR_NULL] are for readonly buffers and PTR_TO_RDWR_BUF[_OR_NULL] for read/write buffers. These new register states will be used by later bpf map element iterator. New register states share some similarity to PTR_TO_TP_BUFFER as it will calculate accessed buffer size during verification time. The accessed buffer size will be later compared to other metrics during later attach/link_create time. Similar to reg_state PTR_TO_BTF_ID_OR_NULL in bpf iterator programs, PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL reg_types can be set at prog->aux->bpf_ctx_arg_aux, and bpf verifier will retrieve the values during btf_ctx_access(). Later bpf map element iterator implementation will show how such information will be assigned during target registeration time. The verifier is also enhanced such that PTR_TO_RDONLY_BUF can be passed to ARG_PTR_TO_MEM[_OR_NULL] helper argument, and PTR_TO_RDWR_BUF can be passed to ARG_PTR_TO_MEM[_OR_NULL] or ARG_PTR_TO_UNINIT_MEM. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184111.590274-1-yhs@fb.com
2020-07-25bpf: Refactor to provide aux info to bpf_iter_init_seq_priv_tYonghong Song
This patch refactored target bpf_iter_init_seq_priv_t callback function to accept additional information. This will be needed in later patches for map element targets since a particular map should be passed to traverse elements for that particular map. In the future, other information may be passed to target as well, e.g., pid, cgroup id, etc. to customize the iterator. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184110.590156-1-yhs@fb.com
2020-07-25bpf: Refactor bpf_iter_reg to have separate seq_info memberYonghong Song
There is no functionality change for this patch. Struct bpf_iter_reg is used to register a bpf_iter target, which includes information for both prog_load, link_create and seq_file creation. This patch puts fields related seq_file creation into a different structure. This will be useful for map elements iterator where one iterator covers different map types and different map types may have different seq_ops, init/fini private_data function and private_data size. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184109.590030-1-yhs@fb.com
2020-07-25bpf: Add bpf_prog iteratorAlexei Starovoitov
It's mostly a copy paste of commit 6086d29def80 ("bpf: Add bpf_map iterator") that is use to implement bpf_seq_file opreations to traverse all bpf programs. v1->v2: Tweak to use build time btf_id Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net>
2020-07-25bpf: Fix pos computation for bpf_iter seq_ops->start()Yonghong Song
Currently, the pos pointer in bpf iterator map/task/task_file seq_ops->start() is always incremented. This is incorrect. It should be increased only if *pos is 0 (for SEQ_START_TOKEN) since these start() function actually returns the first real object. If *pos is not 0, it merely found the object based on the state in seq->private, and not really advancing the *pos. This patch fixed this issue by only incrementing *pos if it is 0. Note that the old *pos calculation, although not correct, does not affect correctness of bpf_iter as bpf_iter seq_file->read() does not support llseek. This patch also renamed "mid" in bpf_map iterator seq_file private data to "map_id" for better clarity. Fixes: 6086d29def80 ("bpf: Add bpf_map iterator") Fixes: eaaacd23910f ("bpf: Add task and task/file iterator targets") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200722195156.4029817-1-yhs@fb.com
2020-07-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
The UDP reuseport conflict was a little bit tricky. The net-next code, via bpf-next, extracted the reuseport handling into a helper so that the BPF sk lookup code could invoke it. At the same time, the logic for reuseport handling of unconnected sockets changed via commit efc6b6f6c3113e8b203b9debfb72d81e0f3dcace which changed the logic to carry on the reuseport result into the rest of the lookup loop if we do not return immediately. This requires moving the reuseport_has_conns() logic into the callers. While we are here, get rid of inline directives as they do not belong in foo.c files. The other changes were cases of more straightforward overlapping modifications. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-25Merge tag 'perf-urgent-2020-07-25' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master Pull uprobe fix from Ingo Molnar: "Fix an interaction/regression between uprobes based shared library tracing & GDB" * tag 'perf-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: uprobes: Change handle_swbp() to send SIGTRAP with si_code=SI_KERNEL, to fix GDB regression
2020-07-24uprobes: Change handle_swbp() to send SIGTRAP with si_code=SI_KERNEL, to fix ↵Oleg Nesterov
GDB regression If a tracee is uprobed and it hits int3 inserted by debugger, handle_swbp() does send_sig(SIGTRAP, current, 0) which means si_code == SI_USER. This used to work when this code was written, but then GDB started to validate si_code and now it simply can't use breakpoints if the tracee has an active uprobe: # cat test.c void unused_func(void) { } int main(void) { return 0; } # gcc -g test.c -o test # perf probe -x ./test -a unused_func # perf record -e probe_test:unused_func gdb ./test -ex run GNU gdb (GDB) 10.0.50.20200714-git ... Program received signal SIGTRAP, Trace/breakpoint trap. 0x00007ffff7ddf909 in dl_main () from /lib64/ld-linux-x86-64.so.2 (gdb) The tracee hits the internal breakpoint inserted by GDB to monitor shared library events but GDB misinterprets this SIGTRAP and reports a signal. Change handle_swbp() to use force_sig(SIGTRAP), this matches do_int3_user() and fixes the problem. This is the minimal fix for -stable, arch/x86/kernel/uprobes.c is equally wrong; it should use send_sigtrap(TRAP_TRACE) instead of send_sig(SIGTRAP), but this doesn't confuse GDB and needs another x86-specific patch. Reported-by: Aaron Merey <amerey@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200723154420.GA32043@redhat.com
2020-07-24sched: Warn if garbage is passed to default_wake_function()Chris Wilson
Since the default_wake_function() passes its flags onto try_to_wake_up(), warn if those flags collide with internal values. Given that the supplied flags are garbage, no repair can be done but at least alert the user to the damage they are causing. In the belief that these errors should be picked up during testing, the warning is only compiled in under CONFIG_SCHED_DEBUG. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: https://lore.kernel.org/r/20200723201042.18861-1-chris@chris-wilson.co.uk
2020-07-22sched: Fix race against ptrace_freeze_trace()Peter Zijlstra
There is apparently one site that violates the rule that only current and ttwu() will modify task->state, namely ptrace_{,un}freeze_traced() will change task->state for a remote task. Oleg explains: "TASK_TRACED/TASK_STOPPED was always protected by siglock. In particular, ttwu(__TASK_TRACED) must be always called with siglock held. That is why ptrace_freeze_traced() assumes it can safely do s/TASK_TRACED/__TASK_TRACED/ under spin_lock(siglock)." This breaks the ordering scheme introduced by commit: dbfb089d360b ("sched: Fix loadavg accounting race") Specifically, the reload not matching no longer implies we don't have to block. Simply things by noting that what we need is a LOAD->STORE ordering and this can be provided by a control dependency. So replace: prev_state = prev->state; raw_spin_lock(&rq->lock); smp_mb__after_spinlock(); /* SMP-MB */ if (... && prev_state && prev_state == prev->state) deactivate_task(); with: prev_state = prev->state; if (... && prev_state) /* CTRL-DEP */ deactivate_task(); Since that already implies the 'prev->state' load must be complete before allowing the 'prev->on_rq = 0' store to become visible. Fixes: dbfb089d360b ("sched: Fix loadavg accounting race") Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Tested-by: Paul Gortmaker <paul.gortmaker@windriver.com> Tested-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-21bpf: net: Use precomputed btf_id for bpf iteratorsYonghong Song
One additional field btf_id is added to struct bpf_ctx_arg_aux to store the precomputed btf_ids. The btf_id is computed at build time with BTF_ID_LIST or BTF_ID_LIST_GLOBAL macro definitions. All existing bpf iterators are changed to used pre-compute btf_ids. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200720163403.1393551-1-yhs@fb.com
2020-07-21bpf: Compute bpf_skc_to_*() helper socket btf ids at build timeYonghong Song
Currently, socket types (struct tcp_sock, udp_sock, etc.) used by bpf_skc_to_*() helpers are computed when vmlinux_btf is first built in the kernel. Commit 5a2798ab32ba ("bpf: Add BTF_ID_LIST/BTF_ID/BTF_ID_UNUSED macros") implemented a mechanism to compute btf_ids at kernel build time which can simplify kernel implementation and reduce runtime overhead by removing in-kernel btf_id calculation. This patch did exactly this, removing in-kernel btf_id computation and utilizing build-time btf_id computation. If CONFIG_DEBUG_INFO_BTF is not defined, BTF_ID_LIST will define an array with size of 5, which is not enough for btf_sock_ids. So define its own static array if CONFIG_DEBUG_INFO_BTF is not defined. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200720163358.1393023-1-yhs@fb.com
2020-07-21bpf: cpumap: Fix possible rcpu kthread hungLorenzo Bianconi
Fix the following cpumap kthread hung. The issue is currently occurring when __cpu_map_load_bpf_program fails (e.g if the bpf prog has not BPF_XDP_CPUMAP as expected_attach_type) $./test_progs -n 101 101/1 cpumap_with_progs:OK 101 xdp_cpumap_attach:OK Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED [ 369.996478] INFO: task cpumap/0/map:7:205 blocked for more than 122 seconds. [ 369.998463] Not tainted 5.8.0-rc4-01472-ge57892f50a07 #212 [ 370.000102] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 370.001918] cpumap/0/map:7 D 0 205 2 0x00004000 [ 370.003228] Call Trace: [ 370.003930] __schedule+0x5c7/0xf50 [ 370.004901] ? io_schedule_timeout+0xb0/0xb0 [ 370.005934] ? static_obj+0x31/0x80 [ 370.006788] ? mark_held_locks+0x24/0x90 [ 370.007752] ? cpu_map_bpf_prog_run_xdp+0x6c0/0x6c0 [ 370.008930] schedule+0x6f/0x160 [ 370.009728] schedule_preempt_disabled+0x14/0x20 [ 370.010829] kthread+0x17b/0x240 [ 370.011433] ? kthread_create_worker_on_cpu+0xd0/0xd0 [ 370.011944] ret_from_fork+0x1f/0x30 [ 370.012348] Showing all locks held in the system: [ 370.013025] 1 lock held by khungtaskd/33: [ 370.013432] #0: ffffffff82b24720 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x28/0x1c3 [ 370.014461] ============================================= Fixes: 9216477449f3 ("bpf: cpumap: Add the possibility to attach an eBPF program to cpumap") Reported-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Jakub Sitnicki <jakub@cloudflare.com> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/e54f2aabf959f298939e5507b09c48f8c2e380be.1595170625.git.lorenzo@kernel.org
2020-07-21bpf, netns: Fix build without CONFIG_INETJakub Sitnicki
When CONFIG_NET is set but CONFIG_INET isn't, build fails with: ld: kernel/bpf/net_namespace.o: in function `netns_bpf_attach_type_unneed': kernel/bpf/net_namespace.c:32: undefined reference to `bpf_sk_lookup_enabled' ld: kernel/bpf/net_namespace.o: in function `netns_bpf_attach_type_need': kernel/bpf/net_namespace.c:43: undefined reference to `bpf_sk_lookup_enabled' This is because without CONFIG_INET bpf_sk_lookup_enabled symbol is not available. Wrap references to bpf_sk_lookup_enabled with preprocessor conditionals. Fixes: 1559b4aa1db4 ("inet: Run SK_LOOKUP BPF program on socket lookup") Reported-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Link: https://lore.kernel.org/bpf/20200721100716.720477-1-jakub@cloudflare.com
2020-07-19Merge tag 'timers-urgent-2020-07-19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master Pull timer fixes from Thomas Gleixner: "Two fixes for the timer wheel: - A timer which is already expired at enqueue time can set the base->next_expiry value backwards. As a consequence base->clk can be set back as well. This can lead to timers expiring early. Add a sanity check to prevent this. - When a timer is queued with an expiry time beyond the wheel capacity then it should be queued in the bucket of the last wheel level which is expiring last. The code adjusted the expiry time to the maximum wheel capacity, which is only correct when the wheel clock is 0. Aside of that the check whether the delta is larger than wheel capacity does not check the delta, it checks the expiry value itself. As a result timers can expire at random. Fix this by checking the right variable and adjust expiry time so it becomes base->clock plus capacity which places it into the outmost bucket in the last wheel level" * tag 'timers-urgent-2020-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timer: Fix wheel index calculation on last level timer: Prevent base->clk from moving backward
2020-07-19Merge tag 'sched-urgent-2020-07-19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master Pull scheduler fixes from Thomas Gleixner: "A set of scheduler fixes: - Plug a load average accounting race which was introduced with a recent optimization casing load average to show bogus numbers. - Fix the rseq CPU id initialization for new tasks. sched_fork() does not update the rseq CPU id so the id is the stale id of the parent task, which can cause user space data corruption. - Handle a 0 return value of task_h_load() correctly in the load balancer, which does not decrease imbalance and therefore pulls until the maximum number of loops is reached, which might be all tasks just created by a fork bomb" * tag 'sched-urgent-2020-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: handle case of task_h_load() returning 0 sched: Fix unreliable rseq cpu_id for new tasks sched: Fix loadavg accounting race
2020-07-19Merge tag 'irq-urgent-2020-07-19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master Pull irq fixes from Thomas Gleixner: "Two fixes for the interrupt subsystem: - Make the handling of the firmware node consistent and do not free the node after the domain has been created successfully. The core code stores a pointer to it which can lead to a use after free or double free. This used to "work" because the pointer was not stored when the initial code was written, but at some point later it was required to store it. Of course nobody noticed that the existing users break that way. - Handle affinity setting on inactive interrupts correctly when hierarchical irq domains are enabled. When interrupts are inactive with the modern hierarchical irqdomain design, the interrupt chips are not necessarily in a state where affinity changes can be handled. The legacy irq chip design allowed this because interrupts are immediately fully initialized at allocation time. X86 has a hacky workaround for this, but other implementations do not. This cased malfunction on GIC-V3. Instead of playing whack a mole to find all affected drivers, change the core code to store the requested affinity setting and then establish it when the interrupt is allocated, which makes the X86 hack go away" * tag 'irq-urgent-2020-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq/affinity: Handle affinity setting on inactive interrupts correctly irqdomain/treewide: Keep firmware node unconditionally allocated
2020-07-17inet: Run SK_LOOKUP BPF program on socket lookupJakub Sitnicki
Run a BPF program before looking up a listening socket on the receive path. Program selects a listening socket to yield as result of socket lookup by calling bpf_sk_assign() helper and returning SK_PASS code. Program can revert its decision by assigning a NULL socket with bpf_sk_assign(). Alternatively, BPF program can also fail the lookup by returning with SK_DROP, or let the lookup continue as usual with SK_PASS on return, when no socket has been selected with bpf_sk_assign(). This lets the user match packets with listening sockets freely at the last possible point on the receive path, where we know that packets are destined for local delivery after undergoing policing, filtering, and routing. With BPF code selecting the socket, directing packets destined to an IP range or to a port range to a single socket becomes possible. In case multiple programs are attached, they are run in series in the order in which they were attached. The end result is determined from return codes of all the programs according to following rules: 1. If any program returned SK_PASS and selected a valid socket, the socket is used as result of socket lookup. 2. If more than one program returned SK_PASS and selected a socket, last selection takes effect. 3. If any program returned SK_DROP, and no program returned SK_PASS and selected a socket, socket lookup fails with -ECONNREFUSED. 4. If all programs returned SK_PASS and none of them selected a socket, socket lookup continues to htable-based lookup. Suggested-by: Marek Majkowski <marek@cloudflare.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200717103536.397595-5-jakub@cloudflare.com
2020-07-17bpf: Introduce SK_LOOKUP program type with a dedicated attach pointJakub Sitnicki
Add a new program type BPF_PROG_TYPE_SK_LOOKUP with a dedicated attach type BPF_SK_LOOKUP. The new program kind is to be invoked by the transport layer when looking up a listening socket for a new connection request for connection oriented protocols, or when looking up an unconnected socket for a packet for connection-less protocols. When called, SK_LOOKUP BPF program can select a socket that will receive the packet. This serves as a mechanism to overcome the limits of what bind() API allows to express. Two use-cases driving this work are: (1) steer packets destined to an IP range, on fixed port to a socket 192.0.2.0/24, port 80 -> NGINX socket (2) steer packets destined to an IP address, on any port to a socket 198.51.100.1, any port -> L7 proxy socket In its run-time context program receives information about the packet that triggered the socket lookup. Namely IP version, L4 protocol identifier, and address 4-tuple. Context can be further extended to include ingress interface identifier. To select a socket BPF program fetches it from a map holding socket references, like SOCKMAP or SOCKHASH, and calls bpf_sk_assign(ctx, sk, ...) helper to record the selection. Transport layer then uses the selected socket as a result of socket lookup. In its basic form, SK_LOOKUP acts as a filter and hence must return either SK_PASS or SK_DROP. If the program returns with SK_PASS, transport should look for a socket to receive the packet, or use the one selected by the program if available, while SK_DROP informs the transport layer that the lookup should fail. This patch only enables the user to attach an SK_LOOKUP program to a network namespace. Subsequent patches hook it up to run on local delivery path in ipv4 and ipv6 stacks. Suggested-by: Marek Majkowski <marek@cloudflare.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200717103536.397595-3-jakub@cloudflare.com
2020-07-17bpf, netns: Handle multiple link attachmentsJakub Sitnicki
Extend the BPF netns link callbacks to rebuild (grow/shrink) or update the prog_array at given position when link gets attached/updated/released. This let's us lift the limit of having just one link attached for the new attach type introduced by subsequent patch. No functional changes intended. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200717103536.397595-2-jakub@cloudflare.com
2020-07-17genirq/affinity: Handle affinity setting on inactive interrupts correctlyThomas Gleixner
Setting interrupt affinity on inactive interrupts is inconsistent when hierarchical irq domains are enabled. The core code should just store the affinity and not call into the irq chip driver for inactive interrupts because the chip drivers may not be in a state to handle such requests. X86 has a hacky workaround for that but all other irq chips have not which causes problems e.g. on GIC V3 ITS. Instead of adding more ugly hacks all over the place, solve the problem in the core code. If the affinity is set on an inactive interrupt then: - Store it in the irq descriptors affinity mask - Update the effective affinity to reflect that so user space has a consistent view - Don't call into the irq chip driver This is the core equivalent of the X86 workaround and works correctly because the affinity setting is established in the irq chip when the interrupt is activated later on. Note, that this is only effective when hierarchical irq domains are enabled by the architecture. Doing it unconditionally would break legacy irq chip implementations. For hierarchial irq domains this works correctly as none of the drivers can have a dependency on affinity setting in inactive state by design. Remove the X86 workaround as it is not longer required. Fixes: 02edee152d6e ("x86/apic/vector: Ignore set_affinity call for inactive interrupts") Reported-by: Ali Saidi <alisaidi@amazon.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Ali Saidi <alisaidi@amazon.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200529015501.15771-1-alisaidi@amazon.com Link: https://lkml.kernel.org/r/877dv2rv25.fsf@nanos.tec.linutronix.de
2020-07-17timer: Fix wheel index calculation on last levelFrederic Weisbecker
When an expiration delta falls into the last level of the wheel, that delta has be compared against the maximum possible delay and reduced to fit in if necessary. However instead of comparing the delta against the maximum, the code compares the actual expiry against the maximum. Then instead of fixing the delta to fit in, it sets the maximum delta as the expiry value. This can result in various undesired outcomes, the worst possible one being a timer expiring 15 days ahead to fire immediately. Fixes: 500462a9de65 ("timers: Switch to a non-cascading wheel") Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20200717140551.29076-2-frederic@kernel.org
2020-07-16sched/fair: handle case of task_h_load() returning 0Vincent Guittot
task_h_load() can return 0 in some situations like running stress-ng mmapfork, which forks thousands of threads, in a sched group on a 224 cores system. The load balance doesn't handle this correctly because env->imbalance never decreases and it will stop pulling tasks only after reaching loop_max, which can be equal to the number of running tasks of the cfs. Make sure that imbalance will be decreased by at least 1. misfit task is the other feature that doesn't handle correctly such situation although it's probably more difficult to face the problem because of the smaller number of CPUs and running tasks on heterogenous system. We can't simply ensure that task_h_load() returns at least one because it would imply to handle underflow in other places. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: <stable@vger.kernel.org> # v4.4+ Link: https://lkml.kernel.org/r/20200710152426.16981-1-vincent.guittot@linaro.org
2020-07-16bpf: cpumap: Implement XDP_REDIRECT for eBPF programs attached to map entriesLorenzo Bianconi
Introduce XDP_REDIRECT support for eBPF programs attached to cpumap entries. This patch has been tested on Marvell ESPRESSObin using a modified version of xdp_redirect_cpu sample in order to attach a XDP program to CPUMAP entries to perform a redirect on the mvneta interface. In particular the following scenario has been tested: rq (cpu0) --> mvneta - XDP_REDIRECT (cpu0) --> CPUMAP - XDP_REDIRECT (cpu1) --> mvneta $./xdp_redirect_cpu -p xdp_cpu_map0 -d eth0 -c 1 -e xdp_redirect \ -f xdp_redirect_kern.o -m tx_port -r eth0 tx: 285.2 Kpps rx: 285.2 Kpps Attaching a simple XDP program on eth0 to perform XDP_TX gives comparable results: tx: 288.4 Kpps rx: 288.4 Kpps Co-developed-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/2cf8373a731867af302b00c4ff16c122630c4980.1594734381.git.lorenzo@kernel.org
2020-07-16bpf: cpumap: Add the possibility to attach an eBPF program to cpumapLorenzo Bianconi
Introduce the capability to attach an eBPF program to cpumap entries. The idea behind this feature is to add the possibility to define on which CPU run the eBPF program if the underlying hw does not support RSS. Current supported verdicts are XDP_DROP and XDP_PASS. This patch has been tested on Marvell ESPRESSObin using xdp_redirect_cpu sample available in the kernel tree to identify possible performance regressions. Results show there are no observable differences in packet-per-second: $./xdp_redirect_cpu --progname xdp_cpu_map0 --dev eth0 --cpu 1 rx: 354.8 Kpps rx: 356.0 Kpps rx: 356.8 Kpps rx: 356.3 Kpps rx: 356.6 Kpps rx: 356.6 Kpps rx: 356.7 Kpps rx: 355.8 Kpps rx: 356.8 Kpps rx: 356.8 Kpps Co-developed-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/5c9febdf903d810b3415732e5cd98491d7d9067a.1594734381.git.lorenzo@kernel.org
2020-07-16cpumap: Formalize map value as a named structLorenzo Bianconi
As it has been already done for devmap, introduce 'struct bpf_cpumap_val' to formalize the expected values that can be passed in for a CPUMAP. Update cpumap code to use the struct. Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/754f950674665dae6139c061d28c1d982aaf4170.1594734381.git.lorenzo@kernel.org
2020-07-16cpumap: Use non-locked version __ptr_ring_consume_batchedJesper Dangaard Brouer
Commit 77361825bb01 ("bpf: cpumap use ptr_ring_consume_batched") changed away from using single frame ptr_ring dequeue (__ptr_ring_consume) to consume a batched, but it uses a locked version, which as the comment explain isn't needed. Change to use the non-locked version __ptr_ring_consume_batched. Fixes: 77361825bb01 ("bpf: cpumap use ptr_ring_consume_batched") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/a9c7d06f9a009e282209f0c8c7b2c5d9b9ad60b9.1594734381.git.lorenzo@kernel.org
2020-07-14Merge branch 'usermode-driver-cleanup' of ↵Alexei Starovoitov
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace into bpf-next
2020-07-14dma-pool: do not allocate pool memory from CMANicolas Saenz Julienne
There is no guarantee to CMA's placement, so allocating a zone specific atomic pool from CMA might return memory from a completely different memory zone. So stop using it. Fixes: c84dc6e68a1d ("dma-pool: add additional coherent pools to map to gfp mask") Reported-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-14dma-pool: make sure atomic pool suits deviceNicolas Saenz Julienne
When allocating DMA memory from a pool, the core can only guess which atomic pool will fit a device's constraints. If it doesn't, get a safer atomic pool and try again. Fixes: c84dc6e68a1d ("dma-pool: add additional coherent pools to map to gfp mask") Reported-by: Jeremy Linton <jeremy.linton@arm.com> Suggested-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-14dma-pool: introduce dma_guess_pool()Nicolas Saenz Julienne
dma-pool's dev_to_pool() creates the false impression that there is a way to grantee a mapping between a device's DMA constraints and an atomic pool. It tuns out it's just a guess, and the device might need to use an atomic pool containing memory from a 'safer' (or lower) memory zone. To help mitigate this, introduce dma_guess_pool() which can be fed a device's DMA constraints and atomic pools already known to be faulty, in order for it to provide an better guess on which pool to use. Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-14dma-pool: get rid of dma_in_atomic_pool()Nicolas Saenz Julienne
The function is only used once and can be simplified to a one-liner. Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-14dma-direct: provide function to check physical memory area validityNicolas Saenz Julienne
dma_coherent_ok() checks if a physical memory area fits a device's DMA constraints. Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-07-13 The following pull-request contains BPF updates for your *net-next* tree. We've added 36 non-merge commits during the last 7 day(s) which contain a total of 62 files changed, 2242 insertions(+), 468 deletions(-). The main changes are: 1) Avoid trace_printk warning banner by switching bpf_trace_printk to use its own tracing event, from Alan. 2) Better libbpf support on older kernels, from Andrii. 3) Additional AF_XDP stats, from Ciara. 4) build time resolution of BTF IDs, from Jiri. 5) BPF_CGROUP_INET_SOCK_RELEASE hook, from Stanislav. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-13bpf: Use dedicated bpf_trace_printk event instead of trace_printk()Alan Maguire
The bpf helper bpf_trace_printk() uses trace_printk() under the hood. This leads to an alarming warning message originating from trace buffer allocation which occurs the first time a program using bpf_trace_printk() is loaded. We can instead create a trace event for bpf_trace_printk() and enable it in-kernel when/if we encounter a program using the bpf_trace_printk() helper. With this approach, trace_printk() is not used directly and no warning message appears. This work was started by Steven (see Link) and finished by Alan; added Steven's Signed-off-by with his permission. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/r/20200628194334.6238b933@oasis.local.home Link: https://lore.kernel.org/bpf/1594641154-18897-2-git-send-email-alan.maguire@oracle.com
2020-07-13bpf: Use BTF_ID to resolve bpf_ctx_convert structJiri Olsa
This way the ID is resolved during compile time, and we can remove the runtime name search. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200711215329.41165-7-jolsa@kernel.org
2020-07-13bpf: Remove btf_id helpers resolvingJiri Olsa
Now when we moved the helpers btf_id arrays into .BTF_ids section, we can remove the code that resolve those IDs in runtime. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200711215329.41165-6-jolsa@kernel.org