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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 /include | |
| parent | c5fc9692d101d1318b0f53f9f691cd88ac029317 (diff) | |
| download | linux-e07b98d9bffe410019dfcf62c3428d4a96c56a2c.tar.gz | |
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 'include')
| -rw-r--r-- | include/linux/bpf_verifier.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/bpf.h | 8 |
2 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 7c6a51924afc..d5093b52b485 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -90,6 +90,7 @@ struct bpf_verifier_env { struct bpf_prog *prog; /* eBPF program being verified */ struct bpf_verifier_stack_elem *head; /* stack of verifier states to be processed */ int stack_size; /* number of states to be processed */ + bool strict_alignment; /* perform strict pointer alignment checks */ struct bpf_verifier_state cur_state; /* current verifier state */ struct bpf_verifier_state_list **explored_states; /* search pruning optimization */ const struct bpf_ext_analyzer_ops *analyzer_ops; /* external analyzer ops */ diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 945a1f5f63c5..94dfa9def355 100644 --- a/include/uapi/linux/bpf.h +++ b/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 */ |