From d00c6473b1ee9050cc36d008c6d30bf0d3de0524 Mon Sep 17 00:00:00 2001 From: Song Liu Date: Fri, 4 Feb 2022 10:57:37 -0800 Subject: [PATCH] bpf: Use prog->jited_len in bpf_prog_ksym_set_addr() Using prog->jited_len is simpler and more accurate than current estimation (header + header->size). Also, fix missing prog->jited_len with multi function program. This hasn't been a real issue before this. Signed-off-by: Song Liu Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220204185742.271030-5-song@kernel.org --- kernel/bpf/core.c | 5 +---- kernel/bpf/verifier.c | 1 + 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 1419922..e3fe53d 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -537,13 +537,10 @@ long bpf_jit_limit_max __read_mostly; static void bpf_prog_ksym_set_addr(struct bpf_prog *prog) { - const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog); - unsigned long addr = (unsigned long)hdr; - WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog)); prog->aux->ksym.start = (unsigned long) prog->bpf_func; - prog->aux->ksym.end = addr + hdr->size; + prog->aux->ksym.end = prog->aux->ksym.start + prog->jited_len; } static void diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 1ae41d0..bbef86c 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -13067,6 +13067,7 @@ static int jit_subprogs(struct bpf_verifier_env *env) prog->jited = 1; prog->bpf_func = func[0]->bpf_func; + prog->jited_len = func[0]->jited_len; prog->aux->func = func; prog->aux->func_cnt = env->subprog_cnt; bpf_prog_jit_attempt_done(prog); -- 2.7.4