Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
Petr Mladek 719f6a7040 printk: Use the main logbuf in NMI when logbuf_lock is available ... The commit 42a0bb3f71 ("printk/nmi: generic solution for safe printk in NMI") caused that printk stores messages into a temporary buffer in NMI context. The buffer is per-CPU and therefore the size is rather limited. It works quite well for NMI backtraces. But there are longer logs that might get printed in NMI context, for example, lockdep warnings, ftrace_dump_on_oops. The temporary buffer is used to avoid deadlocks caused by logbuf_lock. Also it is needed to avoid races with the other temporary buffer that is used when PRINTK_SAFE_CONTEXT is entered. But the main buffer can be used in NMI if the lock is available and we did not interrupt PRINTK_SAFE_CONTEXT. The lock is checked using raw_spin_is_locked(). It might cause false negatives when the lock is taken on another CPU and this CPU is in the safe context from other reasons. Note that the safe context is used also to get console semaphore or when calling console drivers. For this reason, we do the check in printk_nmi_enter(). It makes the handling consistent for the entire NMI handler and avoids reshuffling of the messages. The patch also defines special printk context that allows to use printk_deferred() in NMI. Note that we could not flush the messages to the consoles because console drivers might use many other internal locks. The newly created vprintk_deferred() disables the preemption only around the irq work handling. It is needed there to keep the consistency between the two per-CPU variables. But there is no reason to disable preemption around vprintk_emit(). Finally, the patch puts back explicit serialization of the NMI backtraces from different CPUs. It was removed by the commit a9edc88093 ("x86/nmi: Perform a safe NMI stack trace on all CPUs"). It was not needed because the flushing of the temporary per-CPU buffers was serialized. Link: http://lkml.kernel.org/r/1493912763-24873-1-git-send-email-pmladek@suse.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <rack+kernel@arm.linux.org.uk> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: x86@kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Suggested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>		2017-05-19 14:42:19 +02:00
..
bpf	bpf: enhance verifier to understand stack pointer arithmetic	2017-05-01 11:40:23 -04:00
cgroup	Merge branch 'for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2017-05-01 13:52:24 -07:00
configs	config: android-base: enable hardened usercopy and kernel ASLR	2017-02-27 18:43:46 -08:00
debug	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>	2017-03-02 08:42:34 +01:00
events	Merge branch 'perf/urgent' into perf/core, to pick up fixes	2017-03-28 07:44:25 +02:00
gcov
irq	Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-05-01 15:46:13 -07:00
livepatch	Merge branches 'for-4.12/upstream' and 'for-4.12/klp-hybrid-consistency-model' into for-linus	2017-05-01 21:49:28 +02:00
locking	Merge branch 'akpm' (patches from Andrew)	2017-05-03 17:55:59 -07:00
power	Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-03-03 10:16:38 -08:00
printk	printk: Use the main logbuf in NMI when logbuf_lock is available	2017-05-19 14:42:19 +02:00
rcu	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>	2017-03-02 08:42:34 +01:00
sched	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2017-05-02 19:09:35 -07:00
time	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2017-05-02 19:09:35 -07:00
trace	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2017-05-02 16:40:27 -07:00
.gitignore
acct.c	sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>	2017-03-02 08:42:39 +01:00
async.c
audit.c	Merge branch 'stable-4.12' of git://git.infradead.org/users/pcmoore/audit	2017-05-03 09:21:59 -07:00
audit.h	audit: Use timespec64 to represent audit timestamps	2017-05-02 10:16:05 -04:00
audit_fsnotify.c	Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs	2017-05-03 11:05:15 -07:00
audit_tree.c	Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs	2017-05-03 11:05:15 -07:00
audit_watch.c	Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs	2017-05-03 11:05:15 -07:00
auditfilter.c	audit: kernel generated netlink traffic should have a portid of 0	2017-05-02 10:16:05 -04:00
auditsc.c	Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs	2017-05-03 11:05:15 -07:00
backtracetest.c
bounds.c
capability.c	capability: export has_capability	2017-01-12 07:01:56 -07:00
compat.c	time: Change k_clock nsleep() to use timespec64	2017-04-14 21:49:56 +02:00
configs.c	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
context_tracking.c
cpu.c	Merge branch 'linus' into locking/core, to pick up fixes	2017-04-14 10:29:40 +02:00
cpu_pm.c
crash_dump.c
cred.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/coredump.h>	2017-03-02 08:42:28 +01:00
delayacct.c	sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>	2017-03-02 08:42:39 +01:00
dma.c
elfcore.c
exec_domain.c
exit.c	userfaultfd: non-cooperative: rollback userfaultfd_exit	2017-03-09 17:01:09 -08:00
extable.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2017-02-22 10:15:09 -08:00
fork.c	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2017-05-03 08:50:52 -07:00
freezer.c
futex.c	futex: Clarify mark_wake_futex memory barrier usage	2017-04-15 16:03:46 +02:00
futex_compat.c	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
groups.c	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
hung_task.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>	2017-03-02 08:42:34 +01:00
irq_work.c
jump_label.c	This release has no new tracing features, just clean ups, minor fixes	2017-02-27 13:26:17 -08:00
kallsyms.c	bpf: make jited programs visible in traces	2017-02-17 13:40:05 -05:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks	locking/mutex: Allow MUTEX_SPIN_ON_OWNER when DEBUG_MUTEXES	2016-10-25 11:31:51 +02:00
Kconfig.preempt
kcov.c	kcov: make kcov work properly with KASLR enabled	2016-12-20 09:48:47 -08:00
kexec.c
kexec_core.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk	2017-02-22 17:33:34 -08:00
kexec_file.c	kexec, x86/purgatory: Unbreak it and clean it up	2017-03-10 20:55:09 +01:00
kexec_internal.h	kexec, x86/purgatory: Unbreak it and clean it up	2017-03-10 20:55:09 +01:00
kmod.c	sched/headers, vfs/execve: Prepare to move the do_execve*() prototypes from <linux/sched.h> to <linux/binfmts.h>	2017-03-02 08:42:39 +01:00
kprobes.c	trace/kprobes: Fix check for kretprobe offset within function entry	2017-03-15 17:48:37 -03:00
ksysfs.c	kernel/ksysfs.c: add __ro_after_init to bin_attribute structure	2017-02-24 17:46:56 -08:00
kthread.c	cgroup, kthread: close race window where new kthreads can be migrated to non-root cgroups	2017-03-17 10:18:47 -04:00
latencytop.c	sched/headers: Prepare to move sched_info_on() and force_schedstat_enabled() from <linux/sched.h> to <linux/sched/stat.h>	2017-03-02 08:42:39 +01:00
Makefile	cgroup: move cgroup files under kernel/cgroup/	2016-12-27 14:49:05 -05:00
membarrier.c	Fix: Disable sys_membarrier when nohz_full is enabled	2017-01-23 11:32:16 -08:00
memremap.c	mm, zone_device: Replace {get, put}_zone_device_page() with a single reference to fix pmem crash	2017-05-01 09:15:53 +02:00
module-internal.h
module.c	Merge branch 'stable-4.12' of git://git.infradead.org/users/pcmoore/audit	2017-05-03 09:21:59 -07:00
module_signing.c
notifier.c	kernel/notifier.c: simplify expression	2017-02-24 17:46:56 -08:00
nsproxy.c	perf: Add PERF_RECORD_NAMESPACES to include namespaces related info	2017-03-13 15:57:41 -03:00
padata.c	padata: get_next is never NULL	2017-04-21 20:30:46 +08:00
panic.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>	2017-03-02 08:42:34 +01:00
params.c	boot/param: Move next_arg() function to lib/cmdline.c for later reuse	2017-04-18 10:37:13 +02:00
pid.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>	2017-03-02 08:42:35 +01:00
pid_namespace.c	sched/headers: Prepare for the reduction of <linux/sched.h>'s signal API dependency	2017-03-02 08:42:37 +01:00
profile.c	sched/headers: Prepare to move sched_info_on() and force_schedstat_enabled() from <linux/sched.h> to <linux/sched/stat.h>	2017-03-02 08:42:39 +01:00
ptrace.c	ptrace: fix PTRACE_LISTEN race corrupting task->state	2017-04-08 00:47:48 -07:00
range.c
reboot.c
relay.c	Merge branch 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2017-05-02 11:38:06 -07:00
resource.c
seccomp.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h>	2017-03-02 08:42:36 +01:00
signal.c	sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>	2017-03-02 08:42:39 +01:00
smp.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/idle.h>	2017-03-02 08:42:26 +01:00
smpboot.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>	2017-03-02 08:42:35 +01:00
smpboot.h
softirq.c	sched/core: Remove 'task' parameter and rename tsk_restore_flags() to current_restore_flags()	2017-04-11 09:06:32 +02:00
stacktrace.c	stacktrace/x86: add function for detecting reliable stack traces	2017-03-08 09:18:02 +01:00
stop_machine.c	locking/core, stop_machine: Yield the CPU during stop machine()	2016-11-16 10:15:09 +01:00
sys.c	prlimit,security,selinux: add a security hook for prlimit	2017-03-06 10:43:47 +11:00
sys_ni.c	move aio compat to fs/aio.c	2016-12-22 22:58:37 -05:00
sysctl.c	Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-05-01 16:15:18 -07:00
sysctl_binary.c	net: Remove NET_CORE_BUDGET_USECS from sysctl binary interface.	2017-04-21 15:59:52 -04:00
task_work.c
taskstats.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2016-11-15 10:54:36 -05:00
test_kprobes.c
torture.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h>	2017-03-02 08:42:27 +01:00
tracepoint.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>	2017-03-02 08:42:35 +01:00
tsacct.c	sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>	2017-03-02 08:42:39 +01:00
ucount.c	ucount: Remove the atomicity from ucount->count	2017-03-06 15:26:37 -06:00
uid16.c	sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h>	2017-03-02 08:42:31 +01:00
up.c	smp: Add function to execute a function synchronously on a CPU	2016-09-05 13:52:39 +02:00
user-return-notifier.c
user.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/user.h>	2017-03-02 08:42:29 +01:00
user_namespace.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h>	2017-03-02 08:42:29 +01:00
utsname.c	sched/headers: Prepare to move the task_lock()/unlock() APIs to <linux/sched/task.h>	2017-03-02 08:42:38 +01:00
utsname_sysctl.c	sched/headers: Remove <linux/rwsem.h> from <linux/sched.h>	2017-03-03 01:45:36 +01:00
watchdog.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>	2017-03-02 08:42:34 +01:00
watchdog_hld.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>	2017-03-02 08:42:34 +01:00
workqueue.c	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-05-01 19:12:53 -07:00
workqueue_internal.h