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author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2024-07-15 14:03:44 -0700 |
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committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2024-07-15 14:03:44 -0700 |
commit | a23e1966932464e1c5226cb9ac4ce1d5fc10ba22 (patch) | |
tree | bf5f1b57faa01ca31656bfc48c7d6b6f0bc39189 /kernel/bpf/stackmap.c | |
parent | 7c7b1be19b228b450c2945ec379d7fc6bfef9852 (diff) | |
parent | f3efefb6fdcce604413135bd8d4c5568e53a1f13 (diff) |
Merge branch 'next' into for-linus
Prepare input updates for 6.11 merge window.
Diffstat (limited to 'kernel/bpf/stackmap.c')
-rw-r--r-- | kernel/bpf/stackmap.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 458bb80b14d5..c99f8e5234ac 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -28,7 +28,7 @@ struct bpf_stack_map { void *elems; struct pcpu_freelist freelist; u32 n_buckets; - struct stack_map_bucket *buckets[]; + struct stack_map_bucket *buckets[] __counted_by(n_buckets); }; static inline bool stack_map_use_build_id(struct bpf_map *map) @@ -91,11 +91,14 @@ static struct bpf_map *stack_map_alloc(union bpf_attr *attr) } else if (value_size / 8 > sysctl_perf_event_max_stack) return ERR_PTR(-EINVAL); - /* hash table size must be power of 2 */ - n_buckets = roundup_pow_of_two(attr->max_entries); - if (!n_buckets) + /* hash table size must be power of 2; roundup_pow_of_two() can overflow + * into UB on 32-bit arches, so check that first + */ + if (attr->max_entries > 1UL << 31) return ERR_PTR(-E2BIG); + n_buckets = roundup_pow_of_two(attr->max_entries); + cost = n_buckets * sizeof(struct stack_map_bucket *) + sizeof(*smap); smap = bpf_map_area_alloc(cost, bpf_map_attr_numa_node(attr)); if (!smap) @@ -388,6 +391,7 @@ 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 +414,14 @@ 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 +433,7 @@ 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; |