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| author | David S. Miller <davem@davemloft.net> | 2017-05-10 11:38:07 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-05-11 14:19:00 -0400 |
| commit | e07b98d9bffe410019dfcf62c3428d4a96c56a2c (patch) | |
| tree | 52a3aede39b1bac6a409586bcdd272d9aa958868 /tools | |
| parent | c5fc9692d101d1318b0f53f9f691cd88ac029317 (diff) | |
| download | linux-0-day-e07b98d9bffe410019dfcf62c3428d4a96c56a2c.tar.gz linux-0-day-e07b98d9bffe410019dfcf62c3428d4a96c56a2c.tar.xz | |
bpf: Add strict alignment flag for BPF_PROG_LOAD.
Add a new field, "prog_flags", and an initial flag value
BPF_F_STRICT_ALIGNMENT.
When set, the verifier will enforce strict pointer alignment
regardless of the setting of CONFIG_EFFICIENT_UNALIGNED_ACCESS.
The verifier, in this mode, will also use a fixed value of "2" in
place of NET_IP_ALIGN.
This facilitates test cases that will exercise and validate this part
of the verifier even when run on architectures where alignment doesn't
matter.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/build/feature/test-bpf.c | 1 | ||||
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 11 |
2 files changed, 10 insertions, 2 deletions
diff --git a/tools/build/feature/test-bpf.c b/tools/build/feature/test-bpf.c index ebc6dceddb58c..7598361ef1f10 100644 --- a/tools/build/feature/test-bpf.c +++ b/tools/build/feature/test-bpf.c @@ -29,6 +29,7 @@ int main(void) attr.log_size = 0; attr.log_level = 0; attr.kern_version = 0; + attr.prog_flags = 0; /* * Test existence of __NR_bpf and BPF_PROG_LOAD. diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index e553529929f68..94dfa9def355f 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -132,6 +132,13 @@ enum bpf_attach_type { */ #define BPF_F_ALLOW_OVERRIDE (1U << 0) +/* If BPF_F_STRICT_ALIGNMENT is used in BPF_PROG_LOAD command, the + * verifier will perform strict alignment checking as if the kernel + * has been built with CONFIG_EFFICIENT_UNALIGNED_ACCESS not set, + * and NET_IP_ALIGN defined to 2. + */ +#define BPF_F_STRICT_ALIGNMENT (1U << 0) + #define BPF_PSEUDO_MAP_FD 1 /* flags for BPF_MAP_UPDATE_ELEM command */ @@ -177,6 +184,7 @@ union bpf_attr { __u32 log_size; /* size of user buffer */ __aligned_u64 log_buf; /* user supplied buffer */ __u32 kern_version; /* checked when prog_type=kprobe */ + __u32 prog_flags; }; struct { /* anonymous struct used by BPF_OBJ_* commands */ @@ -481,8 +489,7 @@ union bpf_attr { * u32 bpf_get_socket_uid(skb) * Get the owner uid of the socket stored inside sk_buff. * @skb: pointer to skb - * Return: uid of the socket owner on success or 0 if the socket pointer - * inside sk_buff is NULL + * Return: uid of the socket owner on success or overflowuid if failed. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ |