This is a note to let you know that I've just added the patch titled
perf script: Check session->header.env.arch before using it
to the 5.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
perf-script-check-session-header.env.arch-before-using-it.patch
and it can be found in the queue-5.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 29c77550eef31b0d72a45b49eeab03b8963264e8 Mon Sep 17 00:00:00 2001
From: Song Liu <songliubraving@xxxxxx>
Date: Sun, 3 Oct 2021 22:32:38 -0700
Subject: perf script: Check session->header.env.arch before using it
From: Song Liu <songliubraving@xxxxxx>
commit 29c77550eef31b0d72a45b49eeab03b8963264e8 upstream.
When perf.data is not written cleanly, we would like to process existing
data as much as possible (please see f_header.data.size == 0 condition
in perf_session__read_header). However, perf.data with partial data may
crash perf. Specifically, we see crash in 'perf script' for NULL
session->header.env.arch.
Fix this by checking session->header.env.arch before using it to determine
native_arch. Also split the if condition so it is easier to read.
Committer notes:
If it is a pipe, we already assume is a native arch, so no need to check
session->header.env.arch.
Signed-off-by: Song Liu <songliubraving@xxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: kernel-team@xxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Link: http://lore.kernel.org/lkml/20211004053238.514936-1-songliubraving@xxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/perf/builtin-script.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -4024,11 +4024,15 @@ script_found:
goto out_delete;
uname(&uts);
- if (data.is_pipe || /* assume pipe_mode indicates native_arch */
- !strcmp(uts.machine, session->header.env.arch) ||
- (!strcmp(uts.machine, "x86_64") &&
- !strcmp(session->header.env.arch, "i386")))
+ if (data.is_pipe) { /* Assume pipe_mode indicates native_arch */
native_arch = true;
+ } else if (session->header.env.arch) {
+ if (!strcmp(uts.machine, session->header.env.arch))
+ native_arch = true;
+ else if (!strcmp(uts.machine, "x86_64") &&
+ !strcmp(session->header.env.arch, "i386"))
+ native_arch = true;
+ }
script.session = session;
script__setup_sample_type(&script);
Patches currently in stable-queue which might be from songliubraving@xxxxxx are
queue-5.14/mm-khugepaged-skip-huge-page-collapse-for-special-files.patch
queue-5.14/bpf-use-kvmalloc-for-map-values-in-syscall.patch
queue-5.14/perf-script-check-session-header.env.arch-before-using-it.patch
