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| author |   Stanislav Fomichev <sdf@google.com> | 2019-07-01 10:38:39 -0700 |
|---|---|---|
| committer |   Daniel Borkmann <daniel@iogearbox.net> | 2019-07-08 16:22:55 +0200 |
| commit | 600c70bad6594cb124c641ed05355ca134650ea4 (patch) | |
| tree | 64b117309f808caca760fc11a37284880654eda3 /include/linux/filter.h | |
| parent | Merge branch 'bpf-libbpf-perf-rb-api' (diff) | |
| download | linux-dev-600c70bad6594cb124c641ed05355ca134650ea4.tar.xz linux-dev-600c70bad6594cb124c641ed05355ca134650ea4.zip | |
bpf: allow wide (u64) aligned stores for some fields of bpf_sock_addr
Since commit cd17d7770578 ("bpf/tools: sync bpf.h") clang decided
that it can do a single u64 store into user_ip6[2] instead of two
separate u32 ones:
# 17: (18) r2 = 0x100000000000000
# ; ctx->user_ip6[2] = bpf_htonl(DST_REWRITE_IP6_2);
# 19: (7b) *(u64 *)(r1 +16) = r2
# invalid bpf_context access off=16 size=8
>From the compiler point of view it does look like a correct thing
to do, so let's support it on the kernel side.
Credit to Andrii Nakryiko for a proper implementation of
bpf_ctx_wide_store_ok.
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Fixes: cd17d7770578 ("bpf/tools: sync bpf.h")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'include/linux/filter.h')
| -rw-r--r-- | include/linux/filter.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h index 1fe53e78c7e3..6d944369ca87 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -747,6 +747,12 @@ bpf_ctx_narrow_access_ok(u32 off, u32 size, u32 size_default) return size <= size_default && (size & (size - 1)) == 0; } +#define bpf_ctx_wide_store_ok(off, size, type, field) \ + (size == sizeof(__u64) && \ + off >= offsetof(type, field) && \ + off + sizeof(__u64) <= offsetofend(type, field) && \ + off % sizeof(__u64) == 0) + #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) static inline void bpf_prog_lock_ro(struct bpf_prog *fp) |