Commit de57e99c authored Nov 02, 2018 by Song Liu Committed by Daniel Borkmann Nov 02, 2018

bpf: show real jited address in bpf_prog_info->jited_ksyms



Currently, jited_ksyms in bpf_prog_info shows page addresses of jited
bpf program. The main reason here is to not expose randomized start
address. However, this is not ideal for detailed profiling (find hot
instructions from stack traces). This patch replaces the page address
with real prog start address.

This change is OK because bpf_prog_get_info_by_fd() is only available
to root.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

parent df073470

kernel/bpf/syscall.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -2172,7 +2172,6 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
		user_ksyms = u64_to_user_ptr(info.jited_ksyms);
		for (i = 0; i < ulen; i++) {
		ksym_addr = (ulong) prog->aux->func[i]->bpf_func;
		ksym_addr &= PAGE_MASK;
		if (put_user((u64) ksym_addr, &user_ksyms[i]))
		return -EFAULT;
		}

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