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authorSeiji Aguchi <seiji.aguchi@hds.com>2011-01-12 16:59:30 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-13 08:03:07 -0800
commit04c6862c055fb687c90d9652f32c11a063df15cf (patch)
treeb381c4c2005118f05ce8d2f3d363b73807c0eddf
parentfc2d557c74dc58294b9acc7231a2113ae59af97c (diff)
downloadlwn-04c6862c055fb687c90d9652f32c11a063df15cf.tar.gz
lwn-04c6862c055fb687c90d9652f32c11a063df15cf.zip
kmsg_dump: add kmsg_dump() calls to the reboot, halt, poweroff and emergency_restart paths
We need to know the reason why system rebooted in support service. However, we can't inform our customers of the reason because final messages are lost on current Linux kernel. This patch improves the situation above because the final messages are saved by adding kmsg_dump() to reboot, halt, poweroff and emergency_restart path. Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Marco Stornelli <marco.stornelli@gmail.com> Reviewed-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/kmsg_dump.h4
-rw-r--r--kernel/printk.c4
-rw-r--r--kernel/sys.c6
3 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h
index 24b44145a886..2a0d7d651dc3 100644
--- a/include/linux/kmsg_dump.h
+++ b/include/linux/kmsg_dump.h
@@ -18,6 +18,10 @@ enum kmsg_dump_reason {
KMSG_DUMP_OOPS,
KMSG_DUMP_PANIC,
KMSG_DUMP_KEXEC,
+ KMSG_DUMP_RESTART,
+ KMSG_DUMP_HALT,
+ KMSG_DUMP_POWEROFF,
+ KMSG_DUMP_EMERG,
};
/**
diff --git a/kernel/printk.c b/kernel/printk.c
index f64b8997fc76..0b0c9aa71e89 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1539,6 +1539,10 @@ static const char * const kmsg_reasons[] = {
[KMSG_DUMP_OOPS] = "oops",
[KMSG_DUMP_PANIC] = "panic",
[KMSG_DUMP_KEXEC] = "kexec",
+ [KMSG_DUMP_RESTART] = "restart",
+ [KMSG_DUMP_HALT] = "halt",
+ [KMSG_DUMP_POWEROFF] = "poweroff",
+ [KMSG_DUMP_EMERG] = "emergency_restart",
};
static const char *kmsg_to_str(enum kmsg_dump_reason reason)
diff --git a/kernel/sys.c b/kernel/sys.c
index 2745dcdb6c6c..31b71a276b40 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -43,6 +43,8 @@
#include <linux/kprobes.h>
#include <linux/user_namespace.h>
+#include <linux/kmsg_dump.h>
+
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/unistd.h>
@@ -285,6 +287,7 @@ out_unlock:
*/
void emergency_restart(void)
{
+ kmsg_dump(KMSG_DUMP_EMERG);
machine_emergency_restart();
}
EXPORT_SYMBOL_GPL(emergency_restart);
@@ -312,6 +315,7 @@ void kernel_restart(char *cmd)
printk(KERN_EMERG "Restarting system.\n");
else
printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
+ kmsg_dump(KMSG_DUMP_RESTART);
machine_restart(cmd);
}
EXPORT_SYMBOL_GPL(kernel_restart);
@@ -333,6 +337,7 @@ void kernel_halt(void)
kernel_shutdown_prepare(SYSTEM_HALT);
sysdev_shutdown();
printk(KERN_EMERG "System halted.\n");
+ kmsg_dump(KMSG_DUMP_HALT);
machine_halt();
}
@@ -351,6 +356,7 @@ void kernel_power_off(void)
disable_nonboot_cpus();
sysdev_shutdown();
printk(KERN_EMERG "Power down.\n");
+ kmsg_dump(KMSG_DUMP_POWEROFF);
machine_power_off();
}
EXPORT_SYMBOL_GPL(kernel_power_off);