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author | Mauricio Vasquez B <mauricio.vasquez@polito.it> | 2018-10-18 15:16:20 +0200 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2018-10-19 13:24:31 -0700 |
commit | 2ea864c58f19bf70a0e2415f9f1c53814e07f1b4 (patch) | |
tree | d0de5b3fcc6a4b37ebeb4fc56b0196895cdbc023 | |
parent | c9d29f4658a5a6d2c2ba2afeb20ff763fc6286f9 (diff) | |
download | linux-2ea864c58f19bf70a0e2415f9f1c53814e07f1b4.tar.bz2 |
bpf/verifier: add ARG_PTR_TO_UNINIT_MAP_VALUE
ARG_PTR_TO_UNINIT_MAP_VALUE argument is a pointer to a memory zone
used to save the value of a map. Basically the same as
ARG_PTR_TO_UNINIT_MEM, but the size has not be passed as an extra
argument.
This will be used in the following patch that implements some new
helpers that receive a pointer to be filled with a map value.
Signed-off-by: Mauricio Vasquez B <mauricio.vasquez@polito.it>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
-rw-r--r-- | include/linux/bpf.h | 1 | ||||
-rw-r--r-- | kernel/bpf/verifier.c | 9 |
2 files changed, 7 insertions, 3 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index e60fff48288b..0f8b863e0229 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -138,6 +138,7 @@ enum bpf_arg_type { ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */ ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */ ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */ + ARG_PTR_TO_UNINIT_MAP_VALUE, /* pointer to valid memory used to store a map value */ /* the following constraints used to prototype bpf_memcmp() and other * functions that access data on eBPF program stack diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 3f93a548a642..d84c91ac3b70 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -2117,7 +2117,8 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno, } if (arg_type == ARG_PTR_TO_MAP_KEY || - arg_type == ARG_PTR_TO_MAP_VALUE) { + arg_type == ARG_PTR_TO_MAP_VALUE || + arg_type == ARG_PTR_TO_UNINIT_MAP_VALUE) { expected_type = PTR_TO_STACK; if (!type_is_pkt_pointer(type) && type != PTR_TO_MAP_VALUE && type != expected_type) @@ -2187,7 +2188,8 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno, err = check_helper_mem_access(env, regno, meta->map_ptr->key_size, false, NULL); - } else if (arg_type == ARG_PTR_TO_MAP_VALUE) { + } else if (arg_type == ARG_PTR_TO_MAP_VALUE || + arg_type == ARG_PTR_TO_UNINIT_MAP_VALUE) { /* bpf_map_xxx(..., map_ptr, ..., value) call: * check [value, value + map->value_size) validity */ @@ -2196,9 +2198,10 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno, verbose(env, "invalid map_ptr to access map->value\n"); return -EACCES; } + meta->raw_mode = (arg_type == ARG_PTR_TO_UNINIT_MAP_VALUE); err = check_helper_mem_access(env, regno, meta->map_ptr->value_size, false, - NULL); + meta); } else if (arg_type_is_mem_size(arg_type)) { bool zero_size_allowed = (arg_type == ARG_CONST_SIZE_OR_ZERO); |