From 745e0311306507ddbe1727ac798c8f956812b810 Mon Sep 17 00:00:00 2001 From: Andrei Matei Date: Sun, 10 Dec 2023 17:51:50 -0500 Subject: bpf: Comment on check_mem_size_reg This patch adds a comment to check_mem_size_reg -- a function whose meaning is not very transparent. The function implicitly deals with two registers connected by convention, which is not obvious. Signed-off-by: Andrei Matei Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20231210225149.67639-1-andreimatei1@gmail.com --- kernel/bpf/verifier.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'kernel/bpf') diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index ef27820a24e3..1863826a4ac3 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7256,6 +7256,12 @@ static int check_helper_mem_access(struct bpf_verifier_env *env, int regno, } } +/* verify arguments to helpers or kfuncs consisting of a pointer and an access + * size. + * + * @regno is the register containing the access size. regno-1 is the register + * containing the pointer. + */ static int check_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, u32 regno, bool zero_size_allowed, -- cgit