The patch titled
x86_64: IPI calltraces
has been added to the -mm tree. Its filename is
x86_64-ipi-calltraces.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
From: Kirill Korotaev <dev@xxxxxxxxxx>
Make x86_64 kernel print calltraces on _all_ CPUs on Alt-SysRq-p and NMI
LOCKUP. This patch supplements the one made for i386 some time ago and
included in -mm tree. Since it proved its usefullness many times already
we did the same patch for x86_64.
Signed-off-by: Pavel Emelianov <xemul@xxxxxxxxxx>
Signed-off-by: Kirill Korotaev <dev@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
arch/x86_64/kernel/nmi.c | 13 +++++
arch/x86_64/kernel/process.c | 15 ++++++
arch/x86_64/kernel/smp.c | 79 +++++++++++++++++++++++++++++++++
arch/x86_64/kernel/traps.c | 1
drivers/char/sysrq.c | 2
include/asm-x86_64/nmi.h | 3 +
6 files changed, 112 insertions(+), 1 deletion(-)
diff -puN arch/x86_64/kernel/nmi.c~x86_64-ipi-calltraces arch/x86_64/kernel/nmi.c
--- devel/arch/x86_64/kernel/nmi.c~x86_64-ipi-calltraces 2006-04-17 21:31:41.000000000 -0700
+++ devel-akpm/arch/x86_64/kernel/nmi.c 2006-04-17 21:31:41.000000000 -0700
@@ -527,6 +527,7 @@ static __kprobes int dummy_nmi_callback(
}
static nmi_callback_t nmi_callback = dummy_nmi_callback;
+static nmi_callback_t nmi_ipi_callback = dummy_nmi_callback;
asmlinkage __kprobes void do_nmi(struct pt_regs * regs, long error_code)
{
@@ -536,9 +537,21 @@ asmlinkage __kprobes void do_nmi(struct
add_pda(__nmi_count,1);
if (!rcu_dereference(nmi_callback)(regs, cpu))
default_do_nmi(regs);
+
+ nmi_ipi_callback(regs, cpu);
nmi_exit();
}
+void set_nmi_ipi_callback(nmi_callback_t callback)
+{
+ nmi_ipi_callback = callback;
+}
+
+void unset_nmi_ipi_callback(void)
+{
+ nmi_ipi_callback = dummy_nmi_callback;
+}
+
void set_nmi_callback(nmi_callback_t callback)
{
vmalloc_sync_all();
diff -puN arch/x86_64/kernel/process.c~x86_64-ipi-calltraces arch/x86_64/kernel/process.c
--- devel/arch/x86_64/kernel/process.c~x86_64-ipi-calltraces 2006-04-17 21:31:41.000000000 -0700
+++ devel-akpm/arch/x86_64/kernel/process.c 2006-04-17 21:31:41.000000000 -0700
@@ -338,6 +338,21 @@ void show_regs(struct pt_regs *regs)
show_trace(®s->rsp);
}
+void smp_show_regs(struct pt_regs *regs, void *data)
+{
+ static DEFINE_SPINLOCK(show_regs_lock);
+
+ if (regs == NULL)
+ return;
+
+ bust_spinlocks(1);
+ spin_lock(&show_regs_lock);
+ printk("----------- IPI show regs -----------\n");
+ show_regs(regs);
+ spin_unlock(&show_regs_lock);
+ bust_spinlocks(0);
+}
+
/*
* Free current thread data structures etc..
*/
diff -puN arch/x86_64/kernel/smp.c~x86_64-ipi-calltraces arch/x86_64/kernel/smp.c
--- devel/arch/x86_64/kernel/smp.c~x86_64-ipi-calltraces 2006-04-17 21:31:41.000000000 -0700
+++ devel-akpm/arch/x86_64/kernel/smp.c 2006-04-17 21:31:41.000000000 -0700
@@ -28,6 +28,7 @@
#include <asm/proto.h>
#include <asm/apicdef.h>
#include <asm/idle.h>
+#include <asm/nmi.h>
/*
* Smarter SMP flushing macros.
@@ -444,6 +445,84 @@ int smp_call_function (void (*func) (voi
return 0;
}
+static spinlock_t nmi_call_lock = SPIN_LOCK_UNLOCKED;
+static struct nmi_call_data_struct {
+ smp_nmi_function func;
+ void *info;
+ atomic_t started;
+ atomic_t finished;
+ cpumask_t cpus_called;
+ int wait;
+} *nmi_call_data;
+
+static int smp_nmi_callback(struct pt_regs * regs, int cpu)
+{
+ smp_nmi_function func;
+ void *info;
+ int wait;
+
+ func = nmi_call_data->func;
+ info = nmi_call_data->info;
+ wait = nmi_call_data->wait;
+ ack_APIC_irq();
+ /* prevent from calling func() multiple times */
+ if (cpu_test_and_set(cpu, nmi_call_data->cpus_called))
+ return 0;
+ /*
+ * notify initiating CPU that I've grabbed the data and am
+ * about to execute the function
+ */
+ mb();
+ atomic_inc(&nmi_call_data->started);
+ /* at this point the nmi_call_data structure is out of scope */
+ irq_enter();
+ func(regs, info);
+ irq_exit();
+ if (wait)
+ atomic_inc(&nmi_call_data->finished);
+
+ return 0;
+}
+
+int smp_nmi_call_function(smp_nmi_function func, void *info, int wait)
+{
+ struct nmi_call_data_struct data;
+ int cpus;
+
+ cpus = num_online_cpus() - 1;
+ if (!cpus)
+ return 0;
+
+ data.func = func;
+ data.info = info;
+ data.wait = wait;
+ atomic_set(&data.started, 0);
+ atomic_set(&data.finished, 0);
+ cpus_clear(data.cpus_called);
+ /* prevent this cpu from calling func if NMI happens */
+ cpu_set(smp_processor_id(), data.cpus_called);
+
+ if (!spin_trylock(&nmi_call_lock))
+ return -1;
+
+ nmi_call_data = &data;
+ set_nmi_ipi_callback(smp_nmi_callback);
+ mb();
+
+ /* Send a message to all other CPUs and wait for them to respond */
+ send_IPI_allbutself(APIC_DM_NMI);
+ while (atomic_read(&data.started) != cpus)
+ barrier();
+
+ unset_nmi_ipi_callback();
+ if (wait)
+ while (atomic_read(&data.finished) != cpus)
+ barrier();
+ spin_unlock(&nmi_call_lock);
+
+ return 0;
+}
+
void smp_stop_cpu(void)
{
unsigned long flags;
diff -puN arch/x86_64/kernel/traps.c~x86_64-ipi-calltraces arch/x86_64/kernel/traps.c
--- devel/arch/x86_64/kernel/traps.c~x86_64-ipi-calltraces 2006-04-17 21:31:41.000000000 -0700
+++ devel-akpm/arch/x86_64/kernel/traps.c 2006-04-17 21:31:41.000000000 -0700
@@ -463,6 +463,7 @@ void __kprobes die_nmi(char *str, struct
crash_kexec(regs);
if (panic_on_timeout || panic_on_oops)
panic("nmi watchdog");
+ smp_nmi_call_function(smp_show_regs, NULL, 1);
printk("console shuts up ...\n");
oops_end(flags);
do_exit(SIGSEGV);
diff -puN drivers/char/sysrq.c~x86_64-ipi-calltraces drivers/char/sysrq.c
--- devel/drivers/char/sysrq.c~x86_64-ipi-calltraces 2006-04-17 21:31:41.000000000 -0700
+++ devel-akpm/drivers/char/sysrq.c 2006-04-17 21:31:41.000000000 -0700
@@ -170,7 +170,7 @@ static void sysrq_handle_showregs(int ke
if (pt_regs)
show_regs(pt_regs);
bust_spinlocks(0);
-#ifdef __i386__
+#if defined(__i386__) || defined(__x86_64__)
smp_nmi_call_function(smp_show_regs, NULL, 0);
#endif
}
diff -puN include/asm-x86_64/nmi.h~x86_64-ipi-calltraces include/asm-x86_64/nmi.h
--- devel/include/asm-x86_64/nmi.h~x86_64-ipi-calltraces 2006-04-17 21:31:41.000000000 -0700
+++ devel-akpm/include/asm-x86_64/nmi.h 2006-04-17 21:31:41.000000000 -0700
@@ -24,6 +24,9 @@ void set_nmi_callback(nmi_callback_t cal
* Remove the handler previously set.
*/
void unset_nmi_callback(void);
+
+void set_nmi_ipi_callback(nmi_callback_t callback);
+void unset_nmi_ipi_callback(void);
#ifdef CONFIG_PM
_
Patches currently in -mm which might be from dev@xxxxxxxxxx are
origin.patch
unaligned-access-in-sk_run_filter.patch
x86_64-ipi-calltraces.patch
fix-dcache-race-during-umount.patch
fix-dcache-race-during-umount-fix.patch
prune_one_dentry-tweaks.patch
-
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