diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2019-10-16 05:25:02 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2019-10-17 16:44:36 +0200 |
| commit | 2a02759ef5f8a34792df22b41d5e10658fd7bbd3 (patch) | |
| tree | ebe2c706325515484c567ade7f16e2bee61335c2 /kernel/bpf/verifier.c | |
| parent | bpf: Attach raw_tp program with BTF via type name (diff) | |
| download | linux-2a02759ef5f8a34792df22b41d5e10658fd7bbd3.tar.xz linux-2a02759ef5f8a34792df22b41d5e10658fd7bbd3.zip | |
bpf: Add support for BTF pointers to interpreter
Pointer to BTF object is a pointer to kernel object or NULL.
The memory access in the interpreter has to be done via probe_kernel_read
to avoid page faults.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191016032505.2089704-9-ast@kernel.org
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 42a463e09761..c4b6a2cfcd47 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7581,6 +7581,7 @@ static bool reg_type_mismatch_ok(enum bpf_reg_type type) case PTR_TO_TCP_SOCK: case PTR_TO_TCP_SOCK_OR_NULL: case PTR_TO_XDP_SOCK: + case PTR_TO_BTF_ID: return false; default: return true; @@ -8722,6 +8723,13 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) case PTR_TO_XDP_SOCK: convert_ctx_access = bpf_xdp_sock_convert_ctx_access; break; + case PTR_TO_BTF_ID: + if (type == BPF_WRITE) { + verbose(env, "Writes through BTF pointers are not allowed\n"); + return -EINVAL; + } + insn->code = BPF_LDX | BPF_PROBE_MEM | BPF_SIZE((insn)->code); + continue; default: continue; } |