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-rw-r--r--kernel/bpf/cpumap.c13
-rw-r--r--kernel/bpf/inode.c32
-rw-r--r--kernel/bpf/syscall.c22
-rw-r--r--kernel/bpf/verifier.c235
4 files changed, 183 insertions, 119 deletions
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index 8974b3755670..3c18260403dd 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -162,10 +162,14 @@ static void cpu_map_kthread_stop(struct work_struct *work)
static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu,
struct xdp_frame *xdpf)
{
+ unsigned int hard_start_headroom;
unsigned int frame_size;
void *pkt_data_start;
struct sk_buff *skb;
+ /* Part of headroom was reserved to xdpf */
+ hard_start_headroom = sizeof(struct xdp_frame) + xdpf->headroom;
+
/* build_skb need to place skb_shared_info after SKB end, and
* also want to know the memory "truesize". Thus, need to
* know the memory frame size backing xdp_buff.
@@ -183,15 +187,15 @@ static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu,
* is not at a fixed memory location, with mixed length
* packets, which is bad for cache-line hotness.
*/
- frame_size = SKB_DATA_ALIGN(xdpf->len + xdpf->headroom) +
+ frame_size = SKB_DATA_ALIGN(xdpf->len + hard_start_headroom) +
SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
- pkt_data_start = xdpf->data - xdpf->headroom;
+ pkt_data_start = xdpf->data - hard_start_headroom;
skb = build_skb(pkt_data_start, frame_size);
if (!skb)
return NULL;
- skb_reserve(skb, xdpf->headroom);
+ skb_reserve(skb, hard_start_headroom);
__skb_put(skb, xdpf->len);
if (xdpf->metasize)
skb_metadata_set(skb, xdpf->metasize);
@@ -205,6 +209,9 @@ static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu,
* - RX ring dev queue index (skb_record_rx_queue)
*/
+ /* Allow SKB to reuse area used by xdp_frame */
+ xdp_scrub_frame(xdpf);
+
return skb;
}
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index 2ada5e21dfa6..4a8f390a2b82 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -554,19 +554,6 @@ struct bpf_prog *bpf_prog_get_type_path(const char *name, enum bpf_prog_type typ
}
EXPORT_SYMBOL(bpf_prog_get_type_path);
-static void bpf_evict_inode(struct inode *inode)
-{
- enum bpf_type type;
-
- truncate_inode_pages_final(&inode->i_data);
- clear_inode(inode);
-
- if (S_ISLNK(inode->i_mode))
- kfree(inode->i_link);
- if (!bpf_inode_type(inode, &type))
- bpf_any_put(inode->i_private, type);
-}
-
/*
* Display the mount options in /proc/mounts.
*/
@@ -579,11 +566,28 @@ static int bpf_show_options(struct seq_file *m, struct dentry *root)
return 0;
}
+static void bpf_destroy_inode_deferred(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ enum bpf_type type;
+
+ if (S_ISLNK(inode->i_mode))
+ kfree(inode->i_link);
+ if (!bpf_inode_type(inode, &type))
+ bpf_any_put(inode->i_private, type);
+ free_inode_nonrcu(inode);
+}
+
+static void bpf_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, bpf_destroy_inode_deferred);
+}
+
static const struct super_operations bpf_super_ops = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
.show_options = bpf_show_options,
- .evict_inode = bpf_evict_inode,
+ .destroy_inode = bpf_destroy_inode,
};
enum {
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 62f6bced3a3c..afca36f53c49 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -136,21 +136,29 @@ static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
void *bpf_map_area_alloc(size_t size, int numa_node)
{
- /* We definitely need __GFP_NORETRY, so OOM killer doesn't
- * trigger under memory pressure as we really just want to
- * fail instead.
+ /* We really just want to fail instead of triggering OOM killer
+ * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
+ * which is used for lower order allocation requests.
+ *
+ * It has been observed that higher order allocation requests done by
+ * vmalloc with __GFP_NORETRY being set might fail due to not trying
+ * to reclaim memory from the page cache, thus we set
+ * __GFP_RETRY_MAYFAIL to avoid such situations.
*/
- const gfp_t flags = __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO;
+
+ const gfp_t flags = __GFP_NOWARN | __GFP_ZERO;
void *area;
if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
- area = kmalloc_node(size, GFP_USER | flags, numa_node);
+ area = kmalloc_node(size, GFP_USER | __GFP_NORETRY | flags,
+ numa_node);
if (area != NULL)
return area;
}
- return __vmalloc_node_flags_caller(size, numa_node, GFP_KERNEL | flags,
- __builtin_return_address(0));
+ return __vmalloc_node_flags_caller(size, numa_node,
+ GFP_KERNEL | __GFP_RETRY_MAYFAIL |
+ flags, __builtin_return_address(0));
}
void bpf_map_area_free(void *area)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index ce166a002d16..09d5d972c9ff 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -212,7 +212,7 @@ struct bpf_call_arg_meta {
int access_size;
s64 msize_smax_value;
u64 msize_umax_value;
- int ptr_id;
+ int ref_obj_id;
int func_id;
};
@@ -346,35 +346,23 @@ static bool reg_type_may_be_null(enum bpf_reg_type type)
type == PTR_TO_TCP_SOCK_OR_NULL;
}
-static bool type_is_refcounted(enum bpf_reg_type type)
-{
- return type == PTR_TO_SOCKET;
-}
-
-static bool type_is_refcounted_or_null(enum bpf_reg_type type)
-{
- return type == PTR_TO_SOCKET || type == PTR_TO_SOCKET_OR_NULL;
-}
-
-static bool reg_is_refcounted(const struct bpf_reg_state *reg)
-{
- return type_is_refcounted(reg->type);
-}
-
static bool reg_may_point_to_spin_lock(const struct bpf_reg_state *reg)
{
return reg->type == PTR_TO_MAP_VALUE &&
map_value_has_spin_lock(reg->map_ptr);
}
-static bool reg_is_refcounted_or_null(const struct bpf_reg_state *reg)
+static bool reg_type_may_be_refcounted_or_null(enum bpf_reg_type type)
{
- return type_is_refcounted_or_null(reg->type);
+ return type == PTR_TO_SOCKET ||
+ type == PTR_TO_SOCKET_OR_NULL ||
+ type == PTR_TO_TCP_SOCK ||
+ type == PTR_TO_TCP_SOCK_OR_NULL;
}
-static bool arg_type_is_refcounted(enum bpf_arg_type type)
+static bool arg_type_may_be_refcounted(enum bpf_arg_type type)
{
- return type == ARG_PTR_TO_SOCKET;
+ return type == ARG_PTR_TO_SOCK_COMMON;
}
/* Determine whether the function releases some resources allocated by another
@@ -392,6 +380,12 @@ static bool is_acquire_function(enum bpf_func_id func_id)
func_id == BPF_FUNC_sk_lookup_udp;
}
+static bool is_ptr_cast_function(enum bpf_func_id func_id)
+{
+ return func_id == BPF_FUNC_tcp_sock ||
+ func_id == BPF_FUNC_sk_fullsock;
+}
+
/* string representation of 'enum bpf_reg_type' */
static const char * const reg_type_str[] = {
[NOT_INIT] = "?",
@@ -466,6 +460,8 @@ static void print_verifier_state(struct bpf_verifier_env *env,
verbose(env, ",call_%d", func(env, reg)->callsite);
} else {
verbose(env, "(id=%d", reg->id);
+ if (reg_type_may_be_refcounted_or_null(t))
+ verbose(env, ",ref_obj_id=%d", reg->ref_obj_id);
if (t != SCALAR_VALUE)
verbose(env, ",off=%d", reg->off);
if (type_is_pkt_pointer(t))
@@ -1901,8 +1897,9 @@ continue_func:
}
frame++;
if (frame >= MAX_CALL_FRAMES) {
- WARN_ONCE(1, "verifier bug. Call stack is too deep\n");
- return -EFAULT;
+ verbose(env, "the call stack of %d frames is too deep !\n",
+ frame);
+ return -E2BIG;
}
goto process_func;
}
@@ -2414,16 +2411,15 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
/* Any sk pointer can be ARG_PTR_TO_SOCK_COMMON */
if (!type_is_sk_pointer(type))
goto err_type;
- } else if (arg_type == ARG_PTR_TO_SOCKET) {
- expected_type = PTR_TO_SOCKET;
- if (type != expected_type)
- goto err_type;
- if (meta->ptr_id || !reg->id) {
- verbose(env, "verifier internal error: mismatched references meta=%d, reg=%d\n",
- meta->ptr_id, reg->id);
- return -EFAULT;
+ if (reg->ref_obj_id) {
+ if (meta->ref_obj_id) {
+ verbose(env, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n",
+ regno, reg->ref_obj_id,
+ meta->ref_obj_id);
+ return -EFAULT;
+ }
+ meta->ref_obj_id = reg->ref_obj_id;
}
- meta->ptr_id = reg->id;
} else if (arg_type == ARG_PTR_TO_SPIN_LOCK) {
if (meta->func_id == BPF_FUNC_spin_lock) {
if (process_spin_lock(env, regno, true))
@@ -2740,32 +2736,38 @@ static bool check_arg_pair_ok(const struct bpf_func_proto *fn)
return true;
}
-static bool check_refcount_ok(const struct bpf_func_proto *fn)
+static bool check_refcount_ok(const struct bpf_func_proto *fn, int func_id)
{
int count = 0;
- if (arg_type_is_refcounted(fn->arg1_type))
+ if (arg_type_may_be_refcounted(fn->arg1_type))
count++;
- if (arg_type_is_refcounted(fn->arg2_type))
+ if (arg_type_may_be_refcounted(fn->arg2_type))
count++;
- if (arg_type_is_refcounted(fn->arg3_type))
+ if (arg_type_may_be_refcounted(fn->arg3_type))
count++;
- if (arg_type_is_refcounted(fn->arg4_type))
+ if (arg_type_may_be_refcounted(fn->arg4_type))
count++;
- if (arg_type_is_refcounted(fn->arg5_type))
+ if (arg_type_may_be_refcounted(fn->arg5_type))
count++;
+ /* A reference acquiring function cannot acquire
+ * another refcounted ptr.
+ */
+ if (is_acquire_function(func_id) && count)
+ return false;
+
/* We only support one arg being unreferenced at the moment,
* which is sufficient for the helper functions we have right now.
*/
return count <= 1;
}
-static int check_func_proto(const struct bpf_func_proto *fn)
+static int check_func_proto(const struct bpf_func_proto *fn, int func_id)
{
return check_raw_mode_ok(fn) &&
check_arg_pair_ok(fn) &&
- check_refcount_ok(fn) ? 0 : -EINVAL;
+ check_refcount_ok(fn, func_id) ? 0 : -EINVAL;
}
/* Packet data might have moved, any old PTR_TO_PACKET[_META,_END]
@@ -2799,19 +2801,20 @@ static void clear_all_pkt_pointers(struct bpf_verifier_env *env)
}
static void release_reg_references(struct bpf_verifier_env *env,
- struct bpf_func_state *state, int id)
+ struct bpf_func_state *state,
+ int ref_obj_id)
{
struct bpf_reg_state *regs = state->regs, *reg;
int i;
for (i = 0; i < MAX_BPF_REG; i++)
- if (regs[i].id == id)
+ if (regs[i].ref_obj_id == ref_obj_id)
mark_reg_unknown(env, regs, i);
bpf_for_each_spilled_reg(i, state, reg) {
if (!reg)
continue;
- if (reg_is_refcounted(reg) && reg->id == id)
+ if (reg->ref_obj_id == ref_obj_id)
__mark_reg_unknown(reg);
}
}
@@ -2820,15 +2823,20 @@ static void release_reg_references(struct bpf_verifier_env *env,
* resources. Identify all copies of the same pointer and clear the reference.
*/
static int release_reference(struct bpf_verifier_env *env,
- struct bpf_call_arg_meta *meta)
+ int ref_obj_id)
{
struct bpf_verifier_state *vstate = env->cur_state;
+ int err;
int i;
+ err = release_reference_state(cur_func(env), ref_obj_id);
+ if (err)
+ return err;
+
for (i = 0; i <= vstate->curframe; i++)
- release_reg_references(env, vstate->frame[i], meta->ptr_id);
+ release_reg_references(env, vstate->frame[i], ref_obj_id);
- return release_reference_state(cur_func(env), meta->ptr_id);
+ return 0;
}
static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
@@ -3047,7 +3055,7 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
memset(&meta, 0, sizeof(meta));
meta.pkt_access = fn->pkt_access;
- err = check_func_proto(fn);
+ err = check_func_proto(fn, func_id);
if (err) {
verbose(env, "kernel subsystem misconfigured func %s#%d\n",
func_id_name(func_id), func_id);
@@ -3093,7 +3101,7 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
return err;
}
} else if (is_release_function(func_id)) {
- err = release_reference(env, &meta);
+ err = release_reference(env, meta.ref_obj_id);
if (err) {
verbose(env, "func %s#%d reference has not been acquired before\n",
func_id_name(func_id), func_id);
@@ -3154,8 +3162,10 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
if (id < 0)
return id;
- /* For release_reference() */
+ /* For mark_ptr_or_null_reg() */
regs[BPF_REG_0].id = id;
+ /* For release_reference() */
+ regs[BPF_REG_0].ref_obj_id = id;
} else {
/* For mark_ptr_or_null_reg() */
regs[BPF_REG_0].id = ++env->id_gen;
@@ -3170,6 +3180,10 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
return -EINVAL;
}
+ if (is_ptr_cast_function(func_id))
+ /* For release_reference() */
+ regs[BPF_REG_0].ref_obj_id = meta.ref_obj_id;
+
do_refine_retval_range(regs, fn->ret_type, func_id, &meta);
err = check_map_func_compatibility(env, meta.map_ptr, func_id);
@@ -3368,7 +3382,7 @@ do_sim:
*dst_reg = *ptr_reg;
}
ret = push_stack(env, env->insn_idx + 1, env->insn_idx, true);
- if (!ptr_is_dst_reg)
+ if (!ptr_is_dst_reg && ret)
*dst_reg = tmp;
return !ret ? -EFAULT : 0;
}
@@ -4124,15 +4138,35 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
return 0;
}
+static void __find_good_pkt_pointers(struct bpf_func_state *state,
+ struct bpf_reg_state *dst_reg,
+ enum bpf_reg_type type, u16 new_range)
+{
+ struct bpf_reg_state *reg;
+ int i;
+
+ for (i = 0; i < MAX_BPF_REG; i++) {
+ reg = &state->regs[i];
+ if (reg->type == type && reg->id == dst_reg->id)
+ /* keep the maximum range already checked */
+ reg->range = max(reg->range, new_range);
+ }
+
+ bpf_for_each_spilled_reg(i, state, reg) {
+ if (!reg)
+ continue;
+ if (reg->type == type && reg->id == dst_reg->id)
+ reg->range = max(reg->range, new_range);
+ }
+}
+
static void find_good_pkt_pointers(struct bpf_verifier_state *vstate,
struct bpf_reg_state *dst_reg,
enum bpf_reg_type type,
bool range_right_open)
{
- struct bpf_func_state *state = vstate->frame[vstate->curframe];
- struct bpf_reg_state *regs = state->regs, *reg;
u16 new_range;
- int i, j;
+ int i;
if (dst_reg->off < 0 ||
(dst_reg->off == 0 && range_right_open))
@@ -4197,20 +4231,9 @@ static void find_good_pkt_pointers(struct bpf_verifier_state *vstate,
* the range won't allow anything.
* dst_reg->off is known < MAX_PACKET_OFF, therefore it fits in a u16.
*/
- for (i = 0; i < MAX_BPF_REG; i++)
- if (regs[i].type == type && regs[i].id == dst_reg->id)
- /* keep the maximum range already checked */
- regs[i].range = max(regs[i].range, new_range);
-
- for (j = 0; j <= vstate->curframe; j++) {
- state = vstate->frame[j];
- bpf_for_each_spilled_reg(i, state, reg) {
- if (!reg)
- continue;
- if (reg->type == type && reg->id == dst_reg->id)
- reg->range = max(reg->range, new_range);
- }
- }
+ for (i = 0; i <= vstate->curframe; i++)
+ __find_good_pkt_pointers(vstate->frame[i], dst_reg, type,
+ new_range);
}
/* compute branch direction of the expression "if (reg opcode val) goto target;"
@@ -4665,17 +4688,41 @@ static void mark_ptr_or_null_reg(struct bpf_func_state *state,
} else if (reg->type == PTR_TO_TCP_SOCK_OR_NULL) {
reg->type = PTR_TO_TCP_SOCK;
}
- if (is_null || !(reg_is_refcounted(reg) ||
- reg_may_point_to_spin_lock(reg))) {
- /* We don't need id from this point onwards anymore,
- * thus we should better reset it, so that state
- * pruning has chances to take effect.
+ if (is_null) {
+ /* We don't need id and ref_obj_id from this point
+ * onwards anymore, thus we should better reset it,
+ * so that state pruning has chances to take effect.
+ */
+ reg->id = 0;
+ reg->ref_obj_id = 0;
+ } else if (!reg_may_point_to_spin_lock(reg)) {
+ /* For not-NULL ptr, reg->ref_obj_id will be reset
+ * in release_reg_references().
+ *
+ * reg->id is still used by spin_lock ptr. Other
+ * than spin_lock ptr type, reg->id can be reset.
*/
reg->id = 0;
}
}
}
+static void __mark_ptr_or_null_regs(struct bpf_func_state *state, u32 id,
+ bool is_null)
+{
+ struct bpf_reg_state *reg;
+ int i;
+
+ for (i = 0; i < MAX_BPF_REG; i++)
+ mark_ptr_or_null_reg(state, &state->regs[i], id, is_null);
+
+ bpf_for_each_spilled_reg(i, state, reg) {
+ if (!reg)
+ continue;
+ mark_ptr_or_null_reg(state, reg, id, is_null);
+ }
+}
+
/* The logic is similar to find_good_pkt_pointers(), both could eventually
* be folded together at some point.
*/
@@ -4683,24 +4730,20 @@ static void mark_ptr_or_null_regs(struct bpf_verifier_state *vstate, u32 regno,
bool is_null)
{
struct bpf_func_state *state = vstate->frame[vstate->curframe];
- struct bpf_reg_state *reg, *regs = state->regs;
+ struct bpf_reg_state *regs = state->regs;
+ u32 ref_obj_id = regs[regno].ref_obj_id;
u32 id = regs[regno].id;
- int i, j;
-
- if (reg_is_refcounted_or_null(&regs[regno]) && is_null)
- release_reference_state(state, id);
+ int i;
- for (i = 0; i < MAX_BPF_REG; i++)
- mark_ptr_or_null_reg(state, &regs[i], id, is_null);
+ if (ref_obj_id && ref_obj_id == id && is_null)
+ /* regs[regno] is in the " == NULL" branch.
+ * No one could have freed the reference state before
+ * doing the NULL check.
+ */
+ WARN_ON_ONCE(release_reference_state(state, id));
- for (j = 0; j <= vstate->curframe; j++) {
- state = vstate->frame[j];
- bpf_for_each_spilled_reg(i, state, reg) {
- if (!reg)
- continue;
- mark_ptr_or_null_reg(state, reg, id, is_null);
- }
- }
+ for (i = 0; i <= vstate->curframe; i++)
+ __mark_ptr_or_null_regs(vstate->frame[i], id, is_null);
}
static bool try_match_pkt_pointers(const struct bpf_insn *insn,
@@ -6052,15 +6095,17 @@ static int propagate_liveness(struct bpf_verifier_env *env,
}
/* Propagate read liveness of registers... */
BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG);
- /* We don't need to worry about FP liveness because it's read-only */
- for (i = 0; i < BPF_REG_FP; i++) {
- if (vparent->frame[vparent->curframe]->regs[i].live & REG_LIVE_READ)
- continue;
- if (vstate->frame[vstate->curframe]->regs[i].live & REG_LIVE_READ) {
- err = mark_reg_read(env, &vstate->frame[vstate->curframe]->regs[i],
- &vparent->frame[vstate->curframe]->regs[i]);
- if (err)
- return err;
+ for (frame = 0; frame <= vstate->curframe; frame++) {
+ /* We don't need to worry about FP liveness, it's read-only */
+ for (i = frame < vstate->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++) {
+ if (vparent->frame[frame]->regs[i].live & REG_LIVE_READ)
+ continue;
+ if (vstate->frame[frame]->regs[i].live & REG_LIVE_READ) {
+ err = mark_reg_read(env, &vstate->frame[frame]->regs[i],
+ &vparent->frame[frame]->regs[i]);
+ if (err)
+ return err;
+ }
}
}
generated by cgit (git 2.34.1) at 2024-05-26 01:30:18 +0000