Move some inlined map/prog compatibility checks from the resolve_pseudo_ldimm64() function to the dedicated check_map_prog_compatibility() function. Call the latter function from the add_used_map_from_fd() function directly. This simplifies code and optimizes logic a bit, as before these changes the check_map_prog_compatibility() function was executed on every map usage, which doesn't make sense, as it doesn't include any per-instruction checks, only map type vs. prog type. (This patch also simplifies a consequent patch which will call the add_used_map_from_fd() function from another code path.) Signed-off-by: Anton Protopopov <aspsk@xxxxxxxxxxxxx> Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx> --- kernel/bpf/verifier.c | 101 +++++++++++++++++++----------------------- 1 file changed, 46 insertions(+), 55 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index c855e7905c35..89bba0de853f 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -19368,6 +19368,12 @@ static bool is_tracing_prog_type(enum bpf_prog_type type) } } +static bool bpf_map_is_cgroup_storage(struct bpf_map *map) +{ + return (map->map_type == BPF_MAP_TYPE_CGROUP_STORAGE || + map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE); +} + static int check_map_prog_compatibility(struct bpf_verifier_env *env, struct bpf_map *map, struct bpf_prog *prog) @@ -19446,25 +19452,48 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env, return -EINVAL; } - return 0; -} + if (bpf_map_is_cgroup_storage(map) && + bpf_cgroup_storage_assign(env->prog->aux, map)) { + verbose(env, "only one cgroup storage of each type is allowed\n"); + return -EBUSY; + } -static bool bpf_map_is_cgroup_storage(struct bpf_map *map) -{ - return (map->map_type == BPF_MAP_TYPE_CGROUP_STORAGE || - map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE); + if (map->map_type == BPF_MAP_TYPE_ARENA) { + if (env->prog->aux->arena) { + verbose(env, "Only one arena per program\n"); + return -EBUSY; + } + if (!env->allow_ptr_leaks || !env->bpf_capable) { + verbose(env, "CAP_BPF and CAP_PERFMON are required to use arena\n"); + return -EPERM; + } + if (!env->prog->jit_requested) { + verbose(env, "JIT is required to use arena\n"); + return -EOPNOTSUPP; + } + if (!bpf_jit_supports_arena()) { + verbose(env, "JIT doesn't support arena\n"); + return -EOPNOTSUPP; + } + env->prog->aux->arena = (void *)map; + if (!bpf_arena_get_user_vm_start(env->prog->aux->arena)) { + verbose(env, "arena's user address must be set via map_extra or mmap()\n"); + return -EINVAL; + } + } + + return 0; } /* Add map behind fd to used maps list, if it's not already there, and return - * its index. Also set *reused to true if this map was already in the list of - * used maps. + * its index. * Returns <0 on error, or >= 0 index, on success. */ -static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd, bool *reused) +static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd) { CLASS(fd, f)(fd); struct bpf_map *map; - int i; + int i, err; map = __bpf_map_get(f); if (IS_ERR(map)) { @@ -19473,12 +19502,9 @@ static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd, bool *reus } /* check whether we recorded this map already */ - for (i = 0; i < env->used_map_cnt; i++) { - if (env->used_maps[i] == map) { - *reused = true; + for (i = 0; i < env->used_map_cnt; i++) + if (env->used_maps[i] == map) return i; - } - } if (env->used_map_cnt >= MAX_USED_MAPS) { verbose(env, "The total number of maps per program has reached the limit of %u\n", @@ -19486,6 +19512,10 @@ static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd, bool *reus return -E2BIG; } + err = check_map_prog_compatibility(env, map, env->prog); + if (err) + return err; + if (env->prog->sleepable) atomic64_inc(&map->sleepable_refcnt); @@ -19496,7 +19526,6 @@ static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd, bool *reus */ bpf_map_inc(map); - *reused = false; env->used_maps[env->used_map_cnt++] = map; return env->used_map_cnt - 1; @@ -19533,7 +19562,6 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env) int map_idx; u64 addr; u32 fd; - bool reused; if (i == insn_cnt - 1 || insn[1].code != 0 || insn[1].dst_reg != 0 || insn[1].src_reg != 0 || @@ -19594,7 +19622,7 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env) break; } - map_idx = add_used_map_from_fd(env, fd, &reused); + map_idx = add_used_map_from_fd(env, fd); if (map_idx < 0) return map_idx; map = env->used_maps[map_idx]; @@ -19602,10 +19630,6 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env) aux = &env->insn_aux_data[i]; aux->map_index = map_idx; - err = check_map_prog_compatibility(env, map, env->prog); - if (err) - return err; - if (insn[0].src_reg == BPF_PSEUDO_MAP_FD || insn[0].src_reg == BPF_PSEUDO_MAP_IDX) { addr = (unsigned long)map; @@ -19636,39 +19660,6 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env) insn[0].imm = (u32)addr; insn[1].imm = addr >> 32; - /* proceed with extra checks only if its newly added used map */ - if (reused) - goto next_insn; - - if (bpf_map_is_cgroup_storage(map) && - bpf_cgroup_storage_assign(env->prog->aux, map)) { - verbose(env, "only one cgroup storage of each type is allowed\n"); - return -EBUSY; - } - if (map->map_type == BPF_MAP_TYPE_ARENA) { - if (env->prog->aux->arena) { - verbose(env, "Only one arena per program\n"); - return -EBUSY; - } - if (!env->allow_ptr_leaks || !env->bpf_capable) { - verbose(env, "CAP_BPF and CAP_PERFMON are required to use arena\n"); - return -EPERM; - } - if (!env->prog->jit_requested) { - verbose(env, "JIT is required to use arena\n"); - return -EOPNOTSUPP; - } - if (!bpf_jit_supports_arena()) { - verbose(env, "JIT doesn't support arena\n"); - return -EOPNOTSUPP; - } - env->prog->aux->arena = (void *)map; - if (!bpf_arena_get_user_vm_start(env->prog->aux->arena)) { - verbose(env, "arena's user address must be set via map_extra or mmap()\n"); - return -EINVAL; - } - } - next_insn: insn++; i++; -- 2.34.1