[PATCH 4/23] Add emergency_restart()

From: Eric W. Biederman
Date: Tue Jul 26 2005 - 12:33:21 EST



When the kernel is working well and we want to restart cleanly
kernel_restart is the function to use. But in many instances
the kernel wants to reboot when thing are expected to be working
very badly such as from panic or a software watchdog handler.

This patch adds the function emergency_restart() so that
callers can be clear what semantics they expect when calling
restart. emergency_restart() is expected to be callable
from interrupt context and possibly reliable in even more
trying circumstances.

This is an initial generic implementation for all architectures.

Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
---

include/asm-alpha/emergency-restart.h | 6 ++++++
include/asm-arm/emergency-restart.h | 6 ++++++
include/asm-arm26/emergency-restart.h | 6 ++++++
include/asm-cris/emergency-restart.h | 6 ++++++
include/asm-frv/emergency-restart.h | 6 ++++++
include/asm-generic/emergency-restart.h | 9 +++++++++
include/asm-h8300/emergency-restart.h | 6 ++++++
include/asm-i386/emergency-restart.h | 6 ++++++
include/asm-ia64/emergency-restart.h | 6 ++++++
include/asm-m32r/emergency-restart.h | 6 ++++++
include/asm-m68k/emergency-restart.h | 6 ++++++
include/asm-m68knommu/emergency-restart.h | 6 ++++++
include/asm-mips/emergency-restart.h | 6 ++++++
include/asm-parisc/emergency-restart.h | 6 ++++++
include/asm-ppc/emergency-restart.h | 6 ++++++
include/asm-ppc64/emergency-restart.h | 6 ++++++
include/asm-s390/emergency-restart.h | 6 ++++++
include/asm-sh/emergency-restart.h | 6 ++++++
include/asm-sh64/emergency-restart.h | 6 ++++++
include/asm-sparc/emergency-restart.h | 6 ++++++
include/asm-sparc64/emergency-restart.h | 6 ++++++
include/asm-um/emergency-restart.h | 6 ++++++
include/asm-v850/emergency-restart.h | 6 ++++++
include/asm-x86_64/emergency-restart.h | 6 ++++++
include/asm-xtensa/emergency-restart.h | 6 ++++++
include/linux/reboot.h | 7 +++++++
kernel/sys.c | 6 ++++++
27 files changed, 166 insertions(+), 0 deletions(-)
create mode 100644 include/asm-alpha/emergency-restart.h
create mode 100644 include/asm-arm/emergency-restart.h
create mode 100644 include/asm-arm26/emergency-restart.h
create mode 100644 include/asm-cris/emergency-restart.h
create mode 100644 include/asm-frv/emergency-restart.h
create mode 100644 include/asm-generic/emergency-restart.h
create mode 100644 include/asm-h8300/emergency-restart.h
create mode 100644 include/asm-i386/emergency-restart.h
create mode 100644 include/asm-ia64/emergency-restart.h
create mode 100644 include/asm-m32r/emergency-restart.h
create mode 100644 include/asm-m68k/emergency-restart.h
create mode 100644 include/asm-m68knommu/emergency-restart.h
create mode 100644 include/asm-mips/emergency-restart.h
create mode 100644 include/asm-parisc/emergency-restart.h
create mode 100644 include/asm-ppc/emergency-restart.h
create mode 100644 include/asm-ppc64/emergency-restart.h
create mode 100644 include/asm-s390/emergency-restart.h
create mode 100644 include/asm-sh/emergency-restart.h
create mode 100644 include/asm-sh64/emergency-restart.h
create mode 100644 include/asm-sparc/emergency-restart.h
create mode 100644 include/asm-sparc64/emergency-restart.h
create mode 100644 include/asm-um/emergency-restart.h
create mode 100644 include/asm-v850/emergency-restart.h
create mode 100644 include/asm-x86_64/emergency-restart.h
create mode 100644 include/asm-xtensa/emergency-restart.h

3d8ea7bd8df5d92589d8e02f45b979073c855848
diff --git a/include/asm-alpha/emergency-restart.h b/include/asm-alpha/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-alpha/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-arm/emergency-restart.h b/include/asm-arm/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-arm/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-arm26/emergency-restart.h b/include/asm-arm26/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-arm26/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-cris/emergency-restart.h b/include/asm-cris/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-cris/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-frv/emergency-restart.h b/include/asm-frv/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-frv/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-generic/emergency-restart.h b/include/asm-generic/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-generic/emergency-restart.h
@@ -0,0 +1,9 @@
+#ifndef _ASM_GENERIC_EMERGENCY_RESTART_H
+#define _ASM_GENERIC_EMERGENCY_RESTART_H
+
+static inline void machine_emergency_restart(void)
+{
+ machine_restart(NULL);
+}
+
+#endif /* _ASM_GENERIC_EMERGENCY_RESTART_H */
diff --git a/include/asm-h8300/emergency-restart.h b/include/asm-h8300/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-h8300/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-i386/emergency-restart.h b/include/asm-i386/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-i386/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-ia64/emergency-restart.h b/include/asm-ia64/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-ia64/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-m32r/emergency-restart.h b/include/asm-m32r/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-m32r/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-m68k/emergency-restart.h b/include/asm-m68k/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-m68k/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-m68knommu/emergency-restart.h b/include/asm-m68knommu/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-m68knommu/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-mips/emergency-restart.h b/include/asm-mips/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-mips/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-parisc/emergency-restart.h b/include/asm-parisc/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-parisc/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-ppc/emergency-restart.h b/include/asm-ppc/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-ppc/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-ppc64/emergency-restart.h b/include/asm-ppc64/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-ppc64/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-s390/emergency-restart.h b/include/asm-s390/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-s390/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-sh/emergency-restart.h b/include/asm-sh/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-sh/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-sh64/emergency-restart.h b/include/asm-sh64/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-sh64/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-sparc/emergency-restart.h b/include/asm-sparc/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-sparc/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-sparc64/emergency-restart.h b/include/asm-sparc64/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-sparc64/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-um/emergency-restart.h b/include/asm-um/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-um/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-v850/emergency-restart.h b/include/asm-v850/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-v850/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-x86_64/emergency-restart.h b/include/asm-x86_64/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-x86_64/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/asm-xtensa/emergency-restart.h b/include/asm-xtensa/emergency-restart.h
new file mode 100644
--- /dev/null
+++ b/include/asm-xtensa/emergency-restart.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_EMERGENCY_RESTART_H
+#define _ASM_EMERGENCY_RESTART_H
+
+#include <asm-generic/emergency-restart.h>
+
+#endif /* _ASM_EMERGENCY_RESTART_H */
diff --git a/include/linux/reboot.h b/include/linux/reboot.h
--- a/include/linux/reboot.h
+++ b/include/linux/reboot.h
@@ -64,6 +64,13 @@ extern void kernel_halt(void);
extern void kernel_power_off(void);
extern void kernel_kexec(void);

+/*
+ * Emergency restart, callable from an interrupt handler.
+ */
+
+extern void emergency_restart(void);
+#include <asm/emergency-restart.h>
+
#endif

#endif /* _LINUX_REBOOT_H */
diff --git a/kernel/sys.c b/kernel/sys.c
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -361,6 +361,12 @@ out_unlock:
return retval;
}

+void emergency_restart(void)
+{
+ machine_emergency_restart();
+}
+EXPORT_SYMBOL_GPL(emergency_restart);
+
void kernel_restart(char *cmd)
{
notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
-
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