Patches contributed by Eötvös Lorand University
commit c95dbf27e201587b2a6cf63f8501a0313d9b4801
Author: Ingo Molnar <mingo@elte.hu>
Date: Fri Mar 13 11:14:06 2009 +0100
panic: clean up kernel/panic.c
Impact: cleanup, no code changed
Clean up kernel/panic.c some more and make it more consistent.
LKML-Reference: <49B91A7E.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/panic.c b/kernel/panic.c
index ca75e819d0ea..3fd8c5bf8b39 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -8,19 +8,19 @@
* This function is used through-out the kernel (including mm and fs)
* to indicate a major problem.
*/
+#include <linux/debug_locks.h>
+#include <linux/interrupt.h>
+#include <linux/kallsyms.h>
+#include <linux/notifier.h>
#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/delay.h>
+#include <linux/random.h>
#include <linux/reboot.h>
-#include <linux/notifier.h>
-#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/kexec.h>
+#include <linux/sched.h>
#include <linux/sysrq.h>
-#include <linux/interrupt.h>
+#include <linux/init.h>
#include <linux/nmi.h>
-#include <linux/kexec.h>
-#include <linux/debug_locks.h>
-#include <linux/random.h>
-#include <linux/kallsyms.h>
#include <linux/dmi.h>
int panic_on_oops;
@@ -52,19 +52,15 @@ EXPORT_SYMBOL(panic_blink);
*
* This function never returns.
*/
-
NORET_TYPE void panic(const char * fmt, ...)
{
- long i;
static char buf[1024];
va_list args;
-#if defined(CONFIG_S390)
- unsigned long caller = (unsigned long) __builtin_return_address(0);
-#endif
+ long i;
/*
- * It's possible to come here directly from a panic-assertion and not
- * have preempt disabled. Some functions called from here want
+ * It's possible to come here directly from a panic-assertion and
+ * not have preempt disabled. Some functions called from here want
* preempt to be disabled. No point enabling it later though...
*/
preempt_disable();
@@ -99,19 +95,21 @@ NORET_TYPE void panic(const char * fmt, ...)
if (panic_timeout > 0) {
/*
- * Delay timeout seconds before rebooting the machine.
- * We can't use the "normal" timers since we just panicked..
- */
- printk(KERN_EMERG "Rebooting in %d seconds..",panic_timeout);
+ * Delay timeout seconds before rebooting the machine.
+ * We can't use the "normal" timers since we just panicked.
+ */
+ printk(KERN_EMERG "Rebooting in %d seconds..", panic_timeout);
+
for (i = 0; i < panic_timeout*1000; ) {
touch_nmi_watchdog();
i += panic_blink(i);
mdelay(1);
i++;
}
- /* This will not be a clean reboot, with everything
- * shutting down. But if there is a chance of
- * rebooting the system it will be rebooted.
+ /*
+ * This will not be a clean reboot, with everything
+ * shutting down. But if there is a chance of
+ * rebooting the system it will be rebooted.
*/
emergency_restart();
}
@@ -124,10 +122,15 @@ NORET_TYPE void panic(const char * fmt, ...)
}
#endif
#if defined(CONFIG_S390)
- disabled_wait(caller);
+ {
+ unsigned long caller;
+
+ caller = (unsigned long)__builtin_return_address(0);
+ disabled_wait(caller);
+ }
#endif
local_irq_enable();
- for (i = 0;;) {
+ for (i = 0; ; ) {
touch_softlockup_watchdog();
i += panic_blink(i);
mdelay(1);
@@ -140,23 +143,23 @@ EXPORT_SYMBOL(panic);
struct tnt {
- u8 bit;
- char true;
- char false;
+ u8 bit;
+ char true;
+ char false;
};
static const struct tnt tnts[] = {
- { TAINT_PROPRIETARY_MODULE, 'P', 'G' },
- { TAINT_FORCED_MODULE, 'F', ' ' },
- { TAINT_UNSAFE_SMP, 'S', ' ' },
- { TAINT_FORCED_RMMOD, 'R', ' ' },
- { TAINT_MACHINE_CHECK, 'M', ' ' },
- { TAINT_BAD_PAGE, 'B', ' ' },
- { TAINT_USER, 'U', ' ' },
- { TAINT_DIE, 'D', ' ' },
- { TAINT_OVERRIDDEN_ACPI_TABLE, 'A', ' ' },
- { TAINT_WARN, 'W', ' ' },
- { TAINT_CRAP, 'C', ' ' },
+ { TAINT_PROPRIETARY_MODULE, 'P', 'G' },
+ { TAINT_FORCED_MODULE, 'F', ' ' },
+ { TAINT_UNSAFE_SMP, 'S', ' ' },
+ { TAINT_FORCED_RMMOD, 'R', ' ' },
+ { TAINT_MACHINE_CHECK, 'M', ' ' },
+ { TAINT_BAD_PAGE, 'B', ' ' },
+ { TAINT_USER, 'U', ' ' },
+ { TAINT_DIE, 'D', ' ' },
+ { TAINT_OVERRIDDEN_ACPI_TABLE, 'A', ' ' },
+ { TAINT_WARN, 'W', ' ' },
+ { TAINT_CRAP, 'C', ' ' },
};
/**
@@ -193,7 +196,8 @@ const char *print_tainted(void)
*s = 0;
} else
snprintf(buf, sizeof(buf), "Not tainted");
- return(buf);
+
+ return buf;
}
int test_taint(unsigned flag)
@@ -209,7 +213,8 @@ unsigned long get_taint(void)
void add_taint(unsigned flag)
{
- debug_locks = 0; /* can't trust the integrity of the kernel anymore */
+ /* can't trust the integrity of the kernel anymore: */
+ debug_locks = 0;
set_bit(flag, &tainted_mask);
}
EXPORT_SYMBOL(add_taint);
@@ -264,8 +269,8 @@ static void do_oops_enter_exit(void)
}
/*
- * Return true if the calling CPU is allowed to print oops-related info. This
- * is a bit racy..
+ * Return true if the calling CPU is allowed to print oops-related info.
+ * This is a bit racy..
*/
int oops_may_print(void)
{
@@ -274,20 +279,22 @@ int oops_may_print(void)
/*
* Called when the architecture enters its oops handler, before it prints
- * anything. If this is the first CPU to oops, and it's oopsing the first time
- * then let it proceed.
+ * anything. If this is the first CPU to oops, and it's oopsing the first
+ * time then let it proceed.
*
- * This is all enabled by the pause_on_oops kernel boot option. We do all this
- * to ensure that oopses don't scroll off the screen. It has the side-effect
- * of preventing later-oopsing CPUs from mucking up the display, too.
+ * This is all enabled by the pause_on_oops kernel boot option. We do all
+ * this to ensure that oopses don't scroll off the screen. It has the
+ * side-effect of preventing later-oopsing CPUs from mucking up the display,
+ * too.
*
- * It turns out that the CPU which is allowed to print ends up pausing for the
- * right duration, whereas all the other CPUs pause for twice as long: once in
- * oops_enter(), once in oops_exit().
+ * It turns out that the CPU which is allowed to print ends up pausing for
+ * the right duration, whereas all the other CPUs pause for twice as long:
+ * once in oops_enter(), once in oops_exit().
*/
void oops_enter(void)
{
- debug_locks_off(); /* can't trust the integrity of the kernel anymore */
+ /* can't trust the integrity of the kernel anymore: */
+ debug_locks_off();
do_oops_enter_exit();
}
commit d1dedb52acd98bd5e13e1ff4c4d045d58bbd16fe
Author: Ingo Molnar <mingo@elte.hu>
Date: Fri Mar 13 11:14:06 2009 +0100
panic, smp: provide smp_send_stop() wrapper on UP too
Impact: cleanup, no code changed
Remove an ugly #ifdef CONFIG_SMP from panic(), by providing
an smp_send_stop() wrapper on UP too.
LKML-Reference: <49B91A7E.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 2d3bcb6b37ff..a69db820eed6 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -38,7 +38,7 @@ int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
/*
* main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
* (defined in asm header):
- */
+ */
/*
* stops all CPUs but the current one:
@@ -122,6 +122,8 @@ extern unsigned int setup_max_cpus;
#else /* !SMP */
+static inline void smp_send_stop(void) { }
+
/*
* These macros fold the SMP functionality into a single CPU system
*/
diff --git a/kernel/panic.c b/kernel/panic.c
index 57fb005de546..ca75e819d0ea 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -85,14 +85,12 @@ NORET_TYPE void panic(const char * fmt, ...)
*/
crash_kexec(NULL);
-#ifdef CONFIG_SMP
/*
* Note smp_send_stop is the usual smp shutdown function, which
* unfortunately means it may not be hardened to work in a panic
* situation.
*/
smp_send_stop();
-#endif
atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
commit ffd71da4e3f323b7673b061e6f7e0d0c12dc2b49
Author: Ingo Molnar <mingo@elte.hu>
Date: Fri Mar 13 10:54:24 2009 +0100
panic: decrease oops_in_progress only after having done the panic
Impact: eliminate secondary warnings during panic()
We can panic() in a number of difficult, atomic contexts, hence
we use bust_spinlocks(1) in panic() to increase oops_in_progress,
which prevents various debug checks we have in place.
But in practice this protection only covers the first few printk's
done by panic() - it does not cover the later attempt to stop all
other CPUs and kexec(). If a secondary warning triggers in one of
those facilities that can make the panic message scroll off.
So do bust_spinlocks(0) only much later in panic(). (which code
is only reached if panic policy is relaxed that it can return
after a warning message)
Reported-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49B91A7E.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/panic.c b/kernel/panic.c
index 32fe4eff1b89..57fb005de546 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -77,7 +77,6 @@ NORET_TYPE void panic(const char * fmt, ...)
#ifdef CONFIG_DEBUG_BUGVERBOSE
dump_stack();
#endif
- bust_spinlocks(0);
/*
* If we have crashed and we have a crash kernel loaded let it handle
@@ -136,6 +135,7 @@ NORET_TYPE void panic(const char * fmt, ...)
mdelay(1);
i++;
}
+ bust_spinlocks(0);
}
EXPORT_SYMBOL(panic);
commit cd80a8142efa3468c2cd9fb52845f334c3220d54
Merge: 641cd4cfcdc7 a98fe7f3425c
Author: Ingo Molnar <mingo@elte.hu>
Date: Fri Mar 13 11:05:58 2009 +0100
Merge branch 'x86/core' into core/ipi
commit 641cd4cfcdc71ce01535b31cc4d57d59a1fae1fc
Author: Ingo Molnar <mingo@elte.hu>
Date: Fri Mar 13 10:47:34 2009 +0100
generic-ipi: eliminate WARN_ON()s during oops/panic
Do not output smp-call related warnings in the oops/panic codepath.
Reported-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <49B91A7E.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/smp.c b/kernel/smp.c
index 7ad2262d2eca..858baac568ee 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -5,6 +5,7 @@
*/
#include <linux/rcupdate.h>
#include <linux/rculist.h>
+#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/percpu.h>
#include <linux/init.h>
@@ -285,7 +286,7 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
this_cpu = get_cpu();
/* Can deadlock when called with interrupts disabled */
- WARN_ON(irqs_disabled());
+ WARN_ON_ONCE(irqs_disabled() && !oops_in_progress);
if (cpu == this_cpu) {
local_irq_save(flags);
@@ -329,7 +330,7 @@ void __smp_call_function_single(int cpu, struct call_single_data *data,
csd_lock(data);
/* Can deadlock when called with interrupts disabled */
- WARN_ON(wait && irqs_disabled());
+ WARN_ON_ONCE(wait && irqs_disabled() && !oops_in_progress);
generic_exec_single(cpu, data, wait);
}
@@ -365,7 +366,7 @@ void smp_call_function_many(const struct cpumask *mask,
int cpu, next_cpu, this_cpu = smp_processor_id();
/* Can deadlock when called with interrupts disabled */
- WARN_ON(irqs_disabled());
+ WARN_ON_ONCE(irqs_disabled() && !oops_in_progress);
/* So, what's a CPU they want? Ignoring this one. */
cpu = cpumask_first_and(mask, cpu_online_mask);
commit 88f502fedba82eff252b6420e8b8328e4ae25c67
Author: Ingo Molnar <mingo@elte.hu>
Date: Fri Mar 13 10:32:07 2009 +0100
futex: remove the pointer math from double_unlock_hb, fix
Impact: fix double unlock crash
Thomas Gleixner noticed that the simplified double_unlock_hb()
became ... too unsophisticated: in the hb1 == hb2 case it will
do a double unlock.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Darren Hart <dvhltc@us.ibm.com>
LKML-Reference: <20090312221118.11146.68610.stgit@Aeon>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/futex.c b/kernel/futex.c
index 2331b73f6932..6b50a024bca2 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -659,7 +659,8 @@ static inline void
double_unlock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2)
{
spin_unlock(&hb1->lock);
- spin_unlock(&hb2->lock);
+ if (hb1 != hb2)
+ spin_unlock(&hb2->lock);
}
/*
commit 62a394eb77a1ddea73273f53ed8c3ccf6e04f2fb
Merge: d2e82546ae98 1b3fa2ce6436
Author: Ingo Molnar <mingo@elte.hu>
Date: Fri Mar 13 10:23:39 2009 +0100
Merge branches 'tracing/ftrace' and 'tracing/syscalls'; commit 'v2.6.29-rc8' into tracing/core
commit d2e82546ae98eee353fae57e389f487586fe380d
Merge: 7afe16c2bbf0 899039e8746b
Author: Ingo Molnar <mingo@elte.hu>
Date: Fri Mar 13 06:30:52 2009 +0100
Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace
commit 7afe16c2bbf065e30d692423ad2c7e77c4cfe9a5
Merge: 2084e0225ed1 041b62374c7f
Author: Ingo Molnar <mingo@elte.hu>
Date: Fri Mar 13 06:29:58 2009 +0100
Merge commit 'v2.6.29-rc8' into tracing/ftrace
commit 238a5b4bff2e0929a9ceb41f340137f36a6a75d9
Merge: 17d85bc75645 73e907de7d5c
Author: Ingo Molnar <mingo@elte.hu>
Date: Fri Mar 13 05:54:55 2009 +0100
Merge branch 'cpus4096' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-x86 into cpus4096