Hello,
The panic notifier(i.e. panic_notifier_list) does not be called
if kdump is activated because crash_kexec() does not return.
And there is nothing to notify of crash before crashing by SysRq-c.
Although notify_die() exists, the function depends on architecture.
If notify_die() is added in panic and SysRq respectively like existing
implementation, the code will be ugly.
I think that adding a generic hook in crash_kexec() is better to simplify
the code. The panic_notifier_list-user will have nothing to do.
If you want to catch SysRq, use the crash_notifier_list.
The attached patch is against 2.6.17-rc5. I tested on i386-box.
Thanks,
Akiyama, Nobuyuki
Signed-off-by: Akiyama, Nobuyuki <[email protected]>
---
arch/i386/kernel/traps.c | 4 ++--
arch/powerpc/kernel/traps.c | 2 +-
arch/x86_64/kernel/traps.c | 4 ++--
drivers/char/sysrq.c | 2 +-
include/linux/kexec.h | 11 +++++++++--
kernel/kexec.c | 17 ++++++++++++++++-
kernel/panic.c | 2 +-
7 files changed, 32 insertions(+), 10 deletions(-)
diff -Nurp linux-2.6.17-rc5/arch/i386/kernel/traps.c linux-2.6.17-rc5.mod/arch/i386/kernel/traps.c
--- linux-2.6.17-rc5/arch/i386/kernel/traps.c 2006-05-25 22:23:21.000000000 +0900
+++ linux-2.6.17-rc5.mod/arch/i386/kernel/traps.c 2006-05-30 12:12:25.000000000 +0900
@@ -414,7 +414,7 @@ void die(const char * str, struct pt_reg
return;
if (kexec_should_crash(current))
- crash_kexec(regs);
+ crash_kexec(CRASH_ON_DIE, regs, NULL);
if (in_interrupt())
panic("Fatal exception in interrupt");
@@ -665,7 +665,7 @@ void die_nmi (struct pt_regs *regs, cons
*/
if (!user_mode_vm(regs)) {
current->thread.trap_no = 2;
- crash_kexec(regs);
+ crash_kexec(CRASH_ON_DIE, regs, NULL);
}
do_exit(SIGSEGV);
diff -Nurp linux-2.6.17-rc5/arch/powerpc/kernel/traps.c linux-2.6.17-rc5.mod/arch/powerpc/kernel/traps.c
--- linux-2.6.17-rc5/arch/powerpc/kernel/traps.c 2006-05-25 22:23:21.000000000 +0900
+++ linux-2.6.17-rc5.mod/arch/powerpc/kernel/traps.c 2006-05-30 12:14:07.000000000 +0900
@@ -132,7 +132,7 @@ int die(const char *str, struct pt_regs
if (!crash_dump_start && kexec_should_crash(current)) {
crash_dump_start = 1;
spin_unlock_irq(&die_lock);
- crash_kexec(regs);
+ crash_kexec(CRASH_ON_DIE, regs, NULL);
/* NOTREACHED */
}
spin_unlock_irq(&die_lock);
diff -Nurp linux-2.6.17-rc5/arch/x86_64/kernel/traps.c linux-2.6.17-rc5.mod/arch/x86_64/kernel/traps.c
--- linux-2.6.17-rc5/arch/x86_64/kernel/traps.c 2006-05-25 22:23:22.000000000 +0900
+++ linux-2.6.17-rc5.mod/arch/x86_64/kernel/traps.c 2006-05-30 12:13:24.000000000 +0900
@@ -445,7 +445,7 @@ void __kprobes __die(const char * str, s
printk_address(regs->rip);
printk(" RSP <%016lx>\n", regs->rsp);
if (kexec_should_crash(current))
- crash_kexec(regs);
+ crash_kexec(CRASH_ON_DIE, regs, NULL);
}
void die(const char * str, struct pt_regs * regs, long err)
@@ -469,7 +469,7 @@ void __kprobes die_nmi(char *str, struct
printk(str, safe_smp_processor_id());
show_registers(regs);
if (kexec_should_crash(current))
- crash_kexec(regs);
+ crash_kexec(CRASH_ON_DIE, regs, NULL);
if (panic_on_timeout || panic_on_oops)
panic("nmi watchdog");
printk("console shuts up ...\n");
diff -Nurp linux-2.6.17-rc5/drivers/char/sysrq.c linux-2.6.17-rc5.mod/drivers/char/sysrq.c
--- linux-2.6.17-rc5/drivers/char/sysrq.c 2006-05-25 22:23:22.000000000 +0900
+++ linux-2.6.17-rc5.mod/drivers/char/sysrq.c 2006-05-30 13:26:00.000000000 +0900
@@ -99,7 +99,7 @@ static struct sysrq_key_op sysrq_unraw_o
static void sysrq_handle_crashdump(int key, struct pt_regs *pt_regs,
struct tty_struct *tty)
{
- crash_kexec(pt_regs);
+ crash_kexec(CRASH_ON_SYSRQ, pt_regs, NULL);
}
static struct sysrq_key_op sysrq_crashdump_op = {
.handler = sysrq_handle_crashdump,
diff -Nurp linux-2.6.17-rc5/include/linux/kexec.h linux-2.6.17-rc5.mod/include/linux/kexec.h
--- linux-2.6.17-rc5/include/linux/kexec.h 2006-03-20 14:53:29.000000000 +0900
+++ linux-2.6.17-rc5.mod/include/linux/kexec.h 2006-05-30 17:25:35.000000000 +0900
@@ -1,12 +1,18 @@
#ifndef LINUX_KEXEC_H
#define LINUX_KEXEC_H
+/* crash type for notifier */
+#define CRASH_ON_PANIC 1
+#define CRASH_ON_DIE 2
+#define CRASH_ON_SYSRQ 3
+
#ifdef CONFIG_KEXEC
#include <linux/types.h>
#include <linux/list.h>
#include <linux/linkage.h>
#include <linux/compat.h>
#include <linux/ioport.h>
+#include <linux/notifier.h>
#include <asm/kexec.h>
/* Verify architecture specific macros are defined */
@@ -103,9 +109,10 @@ extern asmlinkage long compat_sys_kexec_
#endif
extern struct page *kimage_alloc_control_pages(struct kimage *image,
unsigned int order);
-extern void crash_kexec(struct pt_regs *);
+extern void crash_kexec(int, struct pt_regs *, void *);
int kexec_should_crash(struct task_struct *);
extern struct kimage *kexec_image;
+extern struct raw_notifier_head crash_notifier_list;
#define KEXEC_ON_CRASH 0x00000001
#define KEXEC_ARCH_MASK 0xffff0000
@@ -133,7 +140,7 @@ extern note_buf_t *crash_notes;
#else /* !CONFIG_KEXEC */
struct pt_regs;
struct task_struct;
-static inline void crash_kexec(struct pt_regs *regs) { }
+static inline void crash_kexec(int type, struct pt_regs *regs, void *v) { }
static inline int kexec_should_crash(struct task_struct *p) { return 0; }
#endif /* CONFIG_KEXEC */
#endif /* LINUX_KEXEC_H */
diff -Nurp linux-2.6.17-rc5/kernel/kexec.c linux-2.6.17-rc5.mod/kernel/kexec.c
--- linux-2.6.17-rc5/kernel/kexec.c 2006-03-20 14:53:29.000000000 +0900
+++ linux-2.6.17-rc5.mod/kernel/kexec.c 2006-05-30 13:16:21.000000000 +0900
@@ -20,6 +20,8 @@
#include <linux/syscalls.h>
#include <linux/ioport.h>
#include <linux/hardirq.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
#include <asm/page.h>
#include <asm/uaccess.h>
@@ -27,6 +29,10 @@
#include <asm/system.h>
#include <asm/semaphore.h>
+
+RAW_NOTIFIER_HEAD(crash_notifier_list);
+EXPORT_SYMBOL(crash_notifier_list);
+
/* Per cpu memory for storing cpu states in case of system crash. */
note_buf_t* crash_notes;
@@ -1040,7 +1046,15 @@ asmlinkage long compat_sys_kexec_load(un
}
#endif
-void crash_kexec(struct pt_regs *regs)
+static void notify_crash(int type, void *v)
+{
+ if(type == CRASH_ON_PANIC)
+ atomic_notifier_call_chain(&panic_notifier_list, 0, v);
+
+ raw_notifier_call_chain(&crash_notifier_list, type, v);
+}
+
+void crash_kexec(int type, struct pt_regs *regs, void *v)
{
struct kimage *image;
int locked;
@@ -1061,6 +1075,7 @@ void crash_kexec(struct pt_regs *regs)
struct pt_regs fixed_regs;
crash_setup_regs(&fixed_regs, regs);
machine_crash_shutdown(&fixed_regs);
+ notify_crash(type, v);
machine_kexec(image);
}
xchg(&kexec_lock, 0);
diff -Nurp linux-2.6.17-rc5/kernel/panic.c linux-2.6.17-rc5.mod/kernel/panic.c
--- linux-2.6.17-rc5/kernel/panic.c 2006-05-25 22:23:30.000000000 +0900
+++ linux-2.6.17-rc5.mod/kernel/panic.c 2006-05-30 12:15:59.000000000 +0900
@@ -85,7 +85,7 @@ NORET_TYPE void panic(const char * fmt,
* everything else.
* Do we want to call this before we try to display a message?
*/
- crash_kexec(NULL);
+ crash_kexec(CRASH_ON_PANIC, NULL, buf);
#ifdef CONFIG_SMP
/*
-
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