diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2024-03-07 17:08:04 -0800 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2024-03-11 15:37:24 -0700 |
| commit | 2edc3de6fb650924a87fffebebc3b7572cbf6e38 (patch) | |
| tree | 507c3f99582f9326e792ab0a5078e424f1902520 /kernel/bpf/btf.c | |
| parent | 6082b6c328b5486da2b356eae94b8b83c98b5565 (diff) | |
| download | linux-stable-2edc3de6fb650924a87fffebebc3b7572cbf6e38.tar.gz linux-stable-2edc3de6fb650924a87fffebebc3b7572cbf6e38.tar.bz2 linux-stable-2edc3de6fb650924a87fffebebc3b7572cbf6e38.zip | |
bpf: Recognize btf_decl_tag("arg: Arena") as PTR_TO_ARENA.
In global bpf functions recognize btf_decl_tag("arg:arena") as PTR_TO_ARENA.
Note, when the verifier sees:
__weak void foo(struct bar *p)
it recognizes 'p' as PTR_TO_MEM and 'struct bar' has to be a struct with scalars.
Hence the only way to use arena pointers in global functions is to tag them with "arg:arena".
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20240308010812.89848-7-alexei.starovoitov@gmail.com
Diffstat (limited to 'kernel/bpf/btf.c')
| -rw-r--r-- | kernel/bpf/btf.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 170d017e8e4a..90c4a32d89ff 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -7111,10 +7111,11 @@ cand_cache_unlock: } enum btf_arg_tag { - ARG_TAG_CTX = 0x1, - ARG_TAG_NONNULL = 0x2, - ARG_TAG_TRUSTED = 0x4, - ARG_TAG_NULLABLE = 0x8, + ARG_TAG_CTX = BIT_ULL(0), + ARG_TAG_NONNULL = BIT_ULL(1), + ARG_TAG_TRUSTED = BIT_ULL(2), + ARG_TAG_NULLABLE = BIT_ULL(3), + ARG_TAG_ARENA = BIT_ULL(4), }; /* Process BTF of a function to produce high-level expectation of function @@ -7226,6 +7227,8 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog) tags |= ARG_TAG_NONNULL; } else if (strcmp(tag, "nullable") == 0) { tags |= ARG_TAG_NULLABLE; + } else if (strcmp(tag, "arena") == 0) { + tags |= ARG_TAG_ARENA; } else { bpf_log(log, "arg#%d has unsupported set of tags\n", i); return -EOPNOTSUPP; @@ -7280,6 +7283,14 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog) sub->args[i].btf_id = kern_type_id; continue; } + if (tags & ARG_TAG_ARENA) { + if (tags & ~ARG_TAG_ARENA) { + bpf_log(log, "arg#%d arena cannot be combined with any other tags\n", i); + return -EINVAL; + } + sub->args[i].arg_type = ARG_PTR_TO_ARENA; + continue; + } if (is_global) { /* generic user data pointer */ u32 mem_size; |