diff options
| author | Kenny Yu <kennyyu@fb.com> | 2022-01-24 10:54:01 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-01-24 19:59:27 -0800 |
| commit | 376040e47334c6dc6a939a32197acceb00fe4acf (patch) | |
| tree | 19b75a8c70bc27d8569ebdaf18079494a525bd82 /include | |
| parent | b77fb25dcb342788d72ad7533163c34b8b823a1d (diff) | |
bpf: Add bpf_copy_from_user_task() helper
This adds a helper for bpf programs to read the memory of other
tasks.
As an example use case at Meta, we are using a bpf task iterator program
and this new helper to print C++ async stack traces for all threads of
a given process.
Signed-off-by: Kenny Yu <kennyyu@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124185403.468466-3-kennyyu@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/bpf.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/bpf.h | 11 |
2 files changed, 12 insertions, 0 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 8c92c974bd12..394305a5e02f 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2243,6 +2243,7 @@ extern const struct bpf_func_proto bpf_kallsyms_lookup_name_proto; extern const struct bpf_func_proto bpf_find_vma_proto; extern const struct bpf_func_proto bpf_loop_proto; extern const struct bpf_func_proto bpf_strncmp_proto; +extern const struct bpf_func_proto bpf_copy_from_user_task_proto; const struct bpf_func_proto *tracing_prog_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 16a7574292a5..4a2f7041ebae 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5076,6 +5076,16 @@ union bpf_attr { * associated to *xdp_md*, at *offset*. * Return * 0 on success, or a negative error in case of failure. + * + * long bpf_copy_from_user_task(void *dst, u32 size, const void *user_ptr, struct task_struct *tsk, u64 flags) + * Description + * Read *size* bytes from user space address *user_ptr* in *tsk*'s + * address space, and stores the data in *dst*. *flags* is not + * used yet and is provided for future extensibility. This helper + * can only be used by sleepable programs. + * Return + * 0 on success, or a negative error in case of failure. On error + * *dst* buffer is zeroed out. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5269,6 +5279,7 @@ union bpf_attr { FN(xdp_get_buff_len), \ FN(xdp_load_bytes), \ FN(xdp_store_bytes), \ + FN(copy_from_user_task), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper |