diff options
| author | Kenny Yu <kennyyu@fb.com> | 2022-01-24 10:54:01 -0800 |
|---|---|---|
| committer | Andrii Nakryiko <andrii.nakryiko@gmail.com> | 2022-01-25 23:37:04 -0800 |
| commit | a9491bb920e7f5cb6cce6aca99cc552316b936dd (patch) | |
| tree | 6e66c49af944076d9040ce4cc6530cdca737badb /include | |
| parent | fb0b8a7ceab14fab8071a1c5195bae59135a232c (diff) | |
| download | libbpf-a9491bb920e7f5cb6cce6aca99cc552316b936dd.tar.gz | |
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/uapi/linux/bpf.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 16a7574..4a2f704 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 |