Feng Tang
c39ea0b9dd
panic: avoid the extra noise dmesg ...
When kernel panic happens, it will first print the panic call stack,
then the ending msg like:
[ 35.743249] ---[ end Kernel panic - not syncing: Fatal exception
[ 35.749975] ------------[ cut here ]------------
The above message are very useful for debugging.
But if system is configured to not reboot on panic, say the
"panic_timeout" parameter equals 0, it will likely print out many noisy
message like WARN() call stack for each and every CPU except the panic
one, messages like below:
WARNING: CPU: 1 PID: 280 at kernel/sched/core.c:1198 set_task_cpu+0x183/0x190
Call Trace:
<IRQ>
try_to_wake_up
default_wake_function
autoremove_wake_function
__wake_up_common
__wake_up_common_lock
__wake_up
wake_up_klogd_work_func
irq_work_run_list
irq_work_tick
update_process_times
tick_sched_timer
__hrtimer_run_queues
hrtimer_interrupt
smp_apic_timer_interrupt
apic_timer_interrupt
For people working in console mode, the screen will first show the panic
call stack, but immediately overridden by these noisy extra messages,
which makes debugging much more difficult, as the original context gets
lost on screen.
Also these noisy messages will confuse some users, as I have seen many bug
reporters posted the noisy message into bugzilla, instead of the real
panic call stack and context.
Adding a flag "suppress_printk" which gets set in panic() to avoid those
noisy messages, without changing current kernel behavior that both panic
blinking and sysrq magic key can work as is, suggested by Petr Mladek.
To verify this, make sure kernel is not configured to reboot on panic and
in console
# echo c > /proc/sysrq-trigger
to see if console only prints out the panic call stack.
Link: http://lkml.kernel.org/r/1551430186-24169-1-git-send-email-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Suggested-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 19:52:51 -07:00
bpf: fix undefined behavior in narrow load handling
2019-05-13 02:05:50 +02:00
kernel/sched/psi.c: expose pressure metrics on root cgroup
2019-05-14 19:52:48 -07:00
DMA mapping updates for 5.2
2019-05-09 08:40:55 -07:00
mm/mmu_notifier: use correct mmu_notifier events for each invalidation
2019-05-14 09:47:49 -07:00
gcov: clang support
2019-05-14 19:52:51 -07:00
Driver core/kobject patches for 5.2-rc1
2019-05-07 13:01:40 -07:00
Driver core/kobject patches for 5.2-rc1
2019-05-07 13:01:40 -07:00
Remove Mysterious Macro Intended to Obscure Weird Behaviours (mmiowb())
2019-05-06 16:57:52 -07:00
Power management updates for 5.2-rc1
2019-05-06 19:40:31 -07:00
panic: avoid the extra noise dmesg
2019-05-14 19:52:51 -07:00
Printk changes for 5.2
2019-05-07 09:18:12 -07:00
kernel/sched/psi.c: expose pressure metrics on root cgroup
2019-05-14 19:52:48 -07:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
2019-05-07 22:03:58 -07:00
This is the bulk of the GPIO changes for the v5.2 kernel cycle:
2019-05-11 10:54:43 -04:00
Provide in-kernel headers to make extending kernel easier
2019-04-29 16:48:03 +02:00
acct_on(): don't mess with freeze protection
2019-04-04 21:04:13 -04:00
treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively
2019-04-09 14:19:06 +02:00
audit: connect LOGIN record to its syscall record
2019-03-20 20:57:48 -04:00
audit_compare_dname_path(): switch to const struct qstr *
2019-04-28 20:33:43 -04:00
audit_compare_dname_path(): switch to const struct qstr *
2019-04-28 20:33:43 -04:00
fsnotify: switch send_to_group() and ->handle_event to const struct qstr *
2019-04-26 13:51:03 -04:00
audit_compare_dname_path(): switch to const struct qstr *
2019-04-28 20:33:43 -04:00
Merge branch 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2019-05-07 20:03:32 -07:00
Merge branch 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2019-05-07 20:03:32 -07:00
backtrace-test: Simplify stack trace handling
2019-04-29 12:37:47 +02:00
kernel/configs: use .incbin directive to embed config_data.gz
2019-03-07 18:32:02 -08:00
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2019-05-06 14:50:46 -07:00
kexec: export PG_offline to VMCOREINFO
2019-03-05 21:07:14 -08:00
mm: change mm_update_next_owner() to update mm->owner with WRITE_ONCE
2019-05-14 19:52:47 -07:00
treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively
2019-04-09 14:19:06 +02:00
kernel/latencytop.c: rename clear_all_latency_tracing to clear_tsk_latency_tracing
2019-05-14 19:52:49 -07:00
mm/gup: change GUP fast to use flags rather than a write 'bool'
2019-05-14 09:47:46 -07:00
Provide in-kernel headers to make extending kernel easier
2019-04-29 16:48:03 +02:00
kernel/hung_task.c: Use continuously blocked time when reporting.
2019-03-07 18:31:59 -08:00
mm/resource: Use resource_overlaps() to simplify region_intersects()
2019-04-19 12:59:36 +02:00
irq_work: Do not raise an IPI when queueing work on the local CPU
2019-04-18 14:07:52 +02:00
locking/static_key: Don't take sleeping locks in __static_key_slow_dec_deferred()
2019-04-29 08:29:21 +02:00
Remove Mysterious Macro Intended to Obscure Weird Behaviours (mmiowb())
2019-05-06 16:57:52 -07:00
kcov: convert kcov.refcount to refcount_t
2019-03-07 18:32:02 -08:00
power/suspend: Add function to disable secondaries for suspend
2019-05-03 19:42:41 +02:00
mm: memblock: make keeping memblock memory opt-in rather than opt-out
2019-05-14 09:47:50 -07:00
Provide in-kernel headers to make extending kernel easier
2019-04-29 16:48:03 +02:00
kprobes: Fix error check when reusing optimized probes
2019-04-16 09:38:16 +02:00
include/: refactor headers to allow kthread.h inclusion in psi_types.h
2019-05-14 19:52:48 -07:00
kernel/latencytop.c: rename clear_all_latency_tracing to clear_tsk_latency_tracing
2019-05-14 19:52:49 -07:00
kernel/Makefile: don't assume that kernel/gen_ikh_data.sh is executable
2019-05-14 19:52:47 -07:00
kernel/memremap.c: remove the unused device_private_entry_fault() export
2019-05-14 09:47:51 -07:00
Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
2019-05-09 12:54:40 -07:00
kernel/notifier.c: double register detection
2019-05-14 19:52:49 -07:00
padata: Replace padata_attr_type default_attrs field with groups
2019-04-25 22:06:11 +02:00
panic: avoid the extra noise dmesg
2019-05-14 19:52:51 -07:00
kernel/pid.c: remove unneeded hash header file
2019-05-14 19:52:51 -07:00
ptrace: take into account saved_sigmask in PTRACE{GET,SET}SIGMASK
2019-03-29 10:01:37 -07:00
Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2019-03-12 13:27:20 -07:00
mm/resource: Use resource_overlaps() to simplify region_intersects()
2019-04-19 12:59:36 +02:00
rseq: Remove superfluous rseq_len from task_struct
2019-04-19 12:39:32 +02:00
audit/stable-5.2 PR 20190507
2019-05-07 19:06:04 -07:00
kernel/signal.c: annotate implicit fall through
2019-05-14 19:52:50 -07:00
softirq: Remove tasklet_hrtimer
2019-03-22 14:36:02 +01:00
stacktrace: Provide common infrastructure
2019-04-29 12:37:57 +02:00
treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively
2019-04-09 14:19:06 +02:00
kernel/sys.c: prctl: fix false positive in validate_prctl_map()
2019-05-14 09:47:44 -07:00
signal: support CLONE_PIDFD with pidfd_send_signal
2019-05-07 14:31:03 +02:00
kernel/sysctl.c: fix proc_do_large_bitmap for large input buffers
2019-05-14 19:52:51 -07:00
genetlink: optionally validate strictly/dumps
2019-04-27 17:07:22 -04:00
torture: Don't try to offline the last CPU
2019-03-26 14:42:53 -07:00
kernel/user.c: clean up some leftover code
2019-05-14 19:52:49 -07:00
watchdog: Fix typo in comment
2019-04-18 14:05:51 +02:00
kernel/watchdog_hld.c: hard lockup message should end with a newline
2019-04-19 09:46:05 -07:00
Merge branch 'for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
2019-05-09 13:48:52 -07:00
sched/core, workqueues: Distangle worker accounting from rq lock
2019-04-16 16:55:15 +02:00
c39ea0b9dd