Commit d00c6473 authored by Song Liu's avatar Song Liu Committed by Alexei Starovoitov
Browse files

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: default avatarSong Liu <song@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220204185742.271030-5-song@kernel.org
parent ed2d9e1a

kernel/bpf/core.c

+1 −4
Original line number Diff line number Diff line
@@ -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

kernel/bpf/verifier.c

+1 −0
Original line number Diff line number Diff line
@@ -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);