diff options
| author | Martin KaFai Lau <kafai@fb.com> | 2018-12-05 17:35:43 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2018-12-05 18:48:40 -0800 |
| commit | 7337224fc150b3b762190425399ac0e8dee380d1 (patch) | |
| tree | 721b91c074ae71bf338f3b28a18264391bf460ea /kernel/bpf/core.c | |
| parent | 30da46b5dc3a9a14db11706d841440e28b12bb53 (diff) | |
bpf: Improve the info.func_info and info.func_info_rec_size behavior
1) When bpf_dump_raw_ok() == false and the kernel can provide >=1
func_info to the userspace, the current behavior is setting
the info.func_info_cnt to 0 instead of setting info.func_info
to 0.
It is different from the behavior in jited_func_lens/nr_jited_func_lens,
jited_ksyms/nr_jited_ksyms...etc.
This patch fixes it. (i.e. set func_info to 0 instead of
func_info_cnt to 0 when bpf_dump_raw_ok() == false).
2) When the userspace passed in info.func_info_cnt == 0, the kernel
will set the expected func_info size back to the
info.func_info_rec_size. It is a way for the userspace to learn
the kernel expected func_info_rec_size introduced in
commit 838e96904ff3 ("bpf: Introduce bpf_func_info").
An exception is the kernel expected size is not set when
func_info is not available for a bpf_prog. This makes the
returned info.func_info_rec_size has different values
depending on the returned value of info.func_info_cnt.
This patch sets the kernel expected size to info.func_info_rec_size
independent of the info.func_info_cnt.
3) The current logic only rejects invalid func_info_rec_size if
func_info_cnt is non zero. This patch also rejects invalid
nonzero info.func_info_rec_size and not equal to the kernel
expected size.
4) Set info.btf_id as long as prog->aux->btf != NULL. That will
setup the later copy_to_user() codes look the same as others
which then easier to understand and maintain.
prog->aux->btf is not NULL only if prog->aux->func_info_cnt > 0.
Breaking up info.btf_id from prog->aux->func_info_cnt is needed
for the later line info patch anyway.
A similar change is made to bpf_get_prog_name().
Fixes: 838e96904ff3 ("bpf: Introduce bpf_func_info")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/core.c')
| -rw-r--r-- | kernel/bpf/core.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 86817ab204e8..628b3970a49b 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -410,7 +410,7 @@ static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); /* prog->aux->name will be ignored if full btf name is available */ - if (prog->aux->btf) { + if (prog->aux->func_info_cnt) { type = btf_type_by_id(prog->aux->btf, prog->aux->func_info[prog->aux->func_idx].type_id); func_name = btf_name_by_offset(prog->aux->btf, type->name_off); |