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 5.4-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-5.4 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 @@ -3779,11 +3779,15 @@ int cmd_script(int argc, const char **ar 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-5.4/powerpc-bpf-fix-bpf_mod-when-imm-1.patch queue-5.4/perf-script-check-session-header.env.arch-before-using-it.patch