diff options
| author | Xu Kuohai <xukuohai@huawei.com> | 2022-07-11 11:08:20 -0400 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2022-07-11 21:04:58 +0200 |
| commit | 535a57a7ffc04932ad83c1a5649b09ba6c93ce83 (patch) | |
| tree | ffc9d4fc14e5a6b489fc1cfa6f5de8001368f164 /kernel/bpf/trampoline.c | |
| parent | 9974d37ea75f01b47d16072b5dad305bd8d23fcc (diff) | |
bpf: Remove is_valid_bpf_tramp_flags()
Before generating bpf trampoline, x86 calls is_valid_bpf_tramp_flags()
to check the input flags. This check is architecture independent.
So, to be consistent with x86, arm64 should also do this check
before generating bpf trampoline.
However, the BPF_TRAMP_F_XXX flags are not used by user code and the
flags argument is almost constant at compile time, so this run time
check is a bit redundant.
Remove is_valid_bpf_tramp_flags() and add some comments to the usage of
BPF_TRAMP_F_XXX flags, as suggested by Alexei.
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20220711150823.2128542-2-xukuohai@huawei.com
Diffstat (limited to 'kernel/bpf/trampoline.c')
| -rw-r--r-- | kernel/bpf/trampoline.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 6cd226584c33..fd69812412ca 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -360,6 +360,9 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr) if (tlinks[BPF_TRAMP_FEXIT].nr_links || tlinks[BPF_TRAMP_MODIFY_RETURN].nr_links) + /* NOTE: BPF_TRAMP_F_RESTORE_REGS and BPF_TRAMP_F_SKIP_FRAME + * should not be set together. + */ flags = BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_SKIP_FRAME; if (ip_arg) |