The patch titled
Subject: tools/testing/selftests/proc/proc-pid-vm.c: hide "segfault at ffffffffff600000" dmesg spam
has been added to the -mm tree. Its filename is
proc-hide-segfault-at-ffffffffff600000-dmesg-spam.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/proc-hide-segfault-at-ffffffffff600000-dmesg-spam.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/proc-hide-segfault-at-ffffffffff600000-dmesg-spam.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Subject: tools/testing/selftests/proc/proc-pid-vm.c: hide "segfault at ffffffffff600000" dmesg spam
Test tries to access vsyscall page and if it doesn't exist gets SIGSEGV
which can spam into dmesg. However the segfault happens by design.
Handle it and carry information via exit code to parent.
Link: http://lkml.kernel.org/r/20190524181256.GA2260@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/proc/proc-pid-vm.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
--- a/tools/testing/selftests/proc/proc-pid-vm.c~proc-hide-segfault-at-ffffffffff600000-dmesg-spam
+++ a/tools/testing/selftests/proc/proc-pid-vm.c
@@ -215,6 +215,11 @@ static const char str_vsyscall[] =
"ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]\n";
#ifdef __x86_64__
+static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___)
+{
+ _exit(1);
+}
+
/*
* vsyscall page can't be unmapped, probe it with memory load.
*/
@@ -231,11 +236,19 @@ static void vsyscall(void)
if (pid == 0) {
struct rlimit rlim = {0, 0};
(void)setrlimit(RLIMIT_CORE, &rlim);
+
+ /* Hide "segfault at ffffffffff600000" messages. */
+ struct sigaction act;
+ memset(&act, 0, sizeof(struct sigaction));
+ act.sa_flags = SA_SIGINFO;
+ act.sa_sigaction = sigaction_SIGSEGV;
+ (void)sigaction(SIGSEGV, &act, NULL);
+
*(volatile int *)0xffffffffff600000UL;
exit(0);
}
- wait(&wstatus);
- if (WIFEXITED(wstatus)) {
+ waitpid(pid, &wstatus, 0);
+ if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) == 0) {
g_vsyscall = true;
}
}
_
Patches currently in -mm which might be from adobriyan@xxxxxxxxx are
ramfs-support-o_tmpfile.patch
swap-ifdef-struct-vm_area_struct-swap_readahead_info.patch
proc-hide-segfault-at-ffffffffff600000-dmesg-spam.patch
tweak-list_poison2-for-better-code-generation-on-x86_64.patch
signal-reorder-struct-sighand_struct.patch
