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| author | Hao Luo <haoluo@google.com> | 2020-09-29 16:50:48 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-10-02 15:00:49 -0700 |
| commit | 63d9b80dcf2c67bc5ade61cbbaa09d7af21f43f1 (patch) | |
| tree | 1eeb951bd0bc20041d49ef77f68cd17f8096fec6 /kernel/bpf/verifier.c | |
| parent | eaa6bcb71ef6ed3dc18fc525ee7e293b06b4882b (diff) | |
| download | lwn-63d9b80dcf2c67bc5ade61cbbaa09d7af21f43f1.tar.gz lwn-63d9b80dcf2c67bc5ade61cbbaa09d7af21f43f1.zip | |
bpf: Introducte bpf_this_cpu_ptr()
Add bpf_this_cpu_ptr() to help access percpu var on this cpu. This
helper always returns a valid pointer, therefore no need to check
returned value for NULL. Also note that all programs run with
preemption disabled, which means that the returned pointer is stable
during all the execution of the program.
Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200929235049.2533242-6-haoluo@google.com
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 216b8ece23ce..d9dbf271ebab 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5128,7 +5128,8 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn regs[BPF_REG_0].type = PTR_TO_MEM_OR_NULL; regs[BPF_REG_0].id = ++env->id_gen; regs[BPF_REG_0].mem_size = meta.mem_size; - } else if (fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL) { + } else if (fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL || + fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID) { const struct btf_type *t; mark_reg_known_zero(env, regs, BPF_REG_0); @@ -5146,10 +5147,14 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn tname, PTR_ERR(ret)); return -EINVAL; } - regs[BPF_REG_0].type = PTR_TO_MEM_OR_NULL; + regs[BPF_REG_0].type = + fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID ? + PTR_TO_MEM : PTR_TO_MEM_OR_NULL; regs[BPF_REG_0].mem_size = tsize; } else { - regs[BPF_REG_0].type = PTR_TO_BTF_ID_OR_NULL; + regs[BPF_REG_0].type = + fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID ? + PTR_TO_BTF_ID : PTR_TO_BTF_ID_OR_NULL; regs[BPF_REG_0].btf_id = meta.ret_btf_id; } } else if (fn->ret_type == RET_PTR_TO_BTF_ID_OR_NULL) { |