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authorSong Liu <songliubraving@fb.com>2018-11-02 10:16:16 -0700
committerDaniel Borkmann <daniel@iogearbox.net>2018-11-02 21:39:01 +0100
commitde57e99ceb65d0d7775cc14a8ba5931d7de1d708 (patch)
tree9c45547a04bce09403e85d8c3f046d9bbc7950da
parentdf0734702a7cbba49d6765bd5ba069340bf9c5db (diff)
downloadlinux-de57e99ceb65d0d7775cc14a8ba5931d7de1d708.tar.bz2
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>
-rw-r--r--kernel/bpf/syscall.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index ccb93277aae2..34a9eef5992c 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -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;
}