diff options
| author |   Daniel Borkmann <daniel@iogearbox.net> | 2017-01-12 11:51:33 +0100 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2017-01-12 10:00:31 -0500 |
| commit | 62c7989b24dbd348c2507ee6458ebf5637d6ddb5 (patch) | |
| tree | 352050f1913fae4683e564607374618338c1c773 /kernel | |
| parent | bpf: pass original insn directly to convert_ctx_access (diff) | |
| download | linux-dev-62c7989b24dbd348c2507ee6458ebf5637d6ddb5.tar.xz linux-dev-62c7989b24dbd348c2507ee6458ebf5637d6ddb5.zip | |
bpf: allow b/h/w/dw access for bpf's cb in ctx
When structs are used to store temporary state in cb[] buffer that is
used with programs and among tail calls, then the generated code will
not always access the buffer in bpf_w chunks. We can ease programming
of it and let this act more natural by allowing for aligned b/h/w/dw
sized access for cb[] ctx member. Various test cases are attached as
well for the selftest suite. Potentially, this can also be reused for
other program types to pass data around.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/verifier.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index df7e47244e75..d60e12c67266 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3165,10 +3165,14 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) insn = env->prog->insnsi + delta; for (i = 0; i < insn_cnt; i++, insn++) { - if (insn->code == (BPF_LDX | BPF_MEM | BPF_W) || + if (insn->code == (BPF_LDX | BPF_MEM | BPF_B) || + insn->code == (BPF_LDX | BPF_MEM | BPF_H) || + insn->code == (BPF_LDX | BPF_MEM | BPF_W) || insn->code == (BPF_LDX | BPF_MEM | BPF_DW)) type = BPF_READ; - else if (insn->code == (BPF_STX | BPF_MEM | BPF_W) || + else if (insn->code == (BPF_STX | BPF_MEM | BPF_B) || + insn->code == (BPF_STX | BPF_MEM | BPF_H) || + insn->code == (BPF_STX | BPF_MEM | BPF_W) || insn->code == (BPF_STX | BPF_MEM | BPF_DW)) type = BPF_WRITE; else |