diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2019-11-14 21:57:16 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2019-11-16 01:45:02 +0300 |
| commit | 8c1b6e69dcc1e11bd24111e3734dd740aaf3fda1 (patch) | |
| tree | b1fcd11bc9e7da8474a587e037c7f32df992b0b1 /include | |
| parent | 91cc1a99740e2ed1d903b5906afb470cc5a07379 (diff) | |
| download | linux-8c1b6e69dcc1e11bd24111e3734dd740aaf3fda1.tar.xz | |
bpf: Compare BTF types of functions arguments with actual types
Make the verifier check that BTF types of function arguments match actual types
passed into top-level BPF program and into BPF-to-BPF calls. If types match
such BPF programs and sub-programs will have full support of BPF trampoline. If
types mismatch the trampoline has to be conservative. It has to save/restore
five program arguments and assume 64-bit scalars.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191114185720.1641606-17-ast@kernel.org
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/bpf.h | 8 | ||||
| -rw-r--r-- | include/linux/bpf_verifier.h | 1 |
2 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 9c48f11fe56e..c70bf04726b4 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -480,6 +480,10 @@ static inline int bpf_trampoline_unlink_prog(struct bpf_prog *prog) static inline void bpf_trampoline_put(struct bpf_trampoline *tr) {} #endif +struct bpf_func_info_aux { + bool unreliable; +}; + struct bpf_prog_aux { atomic_t refcnt; u32 used_map_cnt; @@ -494,6 +498,7 @@ struct bpf_prog_aux { bool verifier_zext; /* Zero extensions has been inserted by verifier. */ bool offload_requested; bool attach_btf_trace; /* true if attaching to BTF-enabled raw tp */ + bool func_proto_unreliable; enum bpf_tramp_prog_type trampoline_prog_type; struct bpf_trampoline *trampoline; struct hlist_node tramp_hlist; @@ -518,6 +523,7 @@ struct bpf_prog_aux { struct bpf_prog_offload *offload; struct btf *btf; struct bpf_func_info *func_info; + struct bpf_func_info_aux *func_info_aux; /* bpf_line_info loaded from userspace. linfo->insn_off * has the xlated insn offset. * Both the main and sub prog share the same linfo. @@ -890,6 +896,8 @@ int btf_distill_func_proto(struct bpf_verifier_log *log, const char *func_name, struct btf_func_model *m); +int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog); + #else /* !CONFIG_BPF_SYSCALL */ static inline struct bpf_prog *bpf_prog_get(u32 ufd) { diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 6e7284ea1468..cdd08bf0ec06 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -343,6 +343,7 @@ static inline bool bpf_verifier_log_needed(const struct bpf_verifier_log *log) #define BPF_MAX_SUBPROGS 256 struct bpf_subprog_info { + /* 'start' has to be the first field otherwise find_subprog() won't work */ u32 start; /* insn idx of function entry point */ u32 linfo_idx; /* The idx to the main_prog->aux->linfo */ u16 stack_depth; /* max. stack depth used by this function */ |