[Patch 2.6.14] Clean up the die notifier registration routines
From: Keith Owens
Date: Wed Nov 02 2005 - 23:13:24 EST
Remove the extraneous die_notifier_lock, notifier_chain_register()
and notifier_chain_unregister already take a lock. Also there is some
work being done to make the generic notify code race safe and the
die_notifier_lock would get in that way of that rework. See
http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2
Add unregister_die_notifier() and export it on all architectures.
Export register_die_notifier() on some architectures, others already
had an export.
Correct include/asm-*/kdebug.h to define the functions as extern.
Remove trailing whitespace in include/asm-x86_64/kdebug.h.
Compile tested on i386 and x86_64, ppc64 and sparc64 have only been
desk checked. The ia64 patch has some additional changes to arch/ia64
code so the ia64 changes are not here, instead they have gone to the
ia64 maintainer.
Signed-off-by: Keith Owens <kaos@xxxxxxx>
---
arch/i386/kernel/traps.c | 14 +++++++-------
arch/ppc64/kernel/traps.c | 14 +++++++-------
arch/sparc64/kernel/traps.c | 15 ++++++++-------
arch/x86_64/kernel/traps.c | 15 ++++++++-------
include/asm-i386/kdebug.h | 6 ++----
include/asm-ppc64/kdebug.h | 8 ++------
include/asm-sparc64/kdebug.h | 7 ++-----
include/asm-x86_64/kdebug.h | 26 ++++++++++++--------------
8 files changed, 48 insertions(+), 57 deletions(-)
Index: linux/arch/i386/kernel/traps.c
===================================================================
--- linux.orig/arch/i386/kernel/traps.c 2005-11-02 12:22:42.197126225 +1100
+++ linux/arch/i386/kernel/traps.c 2005-11-03 13:43:06.024887131 +1100
@@ -93,19 +93,19 @@ asmlinkage void machine_check(void);
static int kstack_depth_to_print = 24;
struct notifier_block *i386die_chain;
-static DEFINE_SPINLOCK(die_notifier_lock);
int register_die_notifier(struct notifier_block *nb)
{
- int err = 0;
- unsigned long flags;
- spin_lock_irqsave(&die_notifier_lock, flags);
- err = notifier_chain_register(&i386die_chain, nb);
- spin_unlock_irqrestore(&die_notifier_lock, flags);
- return err;
+ return notifier_chain_register(&i386die_chain, nb);
}
EXPORT_SYMBOL(register_die_notifier);
+int unregister_die_notifier(struct notifier_block *nb)
+{
+ return notifier_chain_unregister(&i386die_chain, nb);
+}
+EXPORT_SYMBOL(unregister_die_notifier);
+
static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
{
return p > (void *)tinfo &&
Index: linux/arch/ppc64/kernel/traps.c
===================================================================
--- linux.orig/arch/ppc64/kernel/traps.c 2005-10-28 10:02:08.000000000 +1000
+++ linux/arch/ppc64/kernel/traps.c 2005-11-03 13:45:15.066635994 +1100
@@ -63,18 +63,18 @@ EXPORT_SYMBOL(__debugger_fault_handler);
#endif
struct notifier_block *ppc64_die_chain;
-static DEFINE_SPINLOCK(die_notifier_lock);
int register_die_notifier(struct notifier_block *nb)
{
- int err = 0;
- unsigned long flags;
+ return notifier_chain_register(&ppc64_die_chain, nb);
+}
+EXPORT_SYMBOL(register_die_notifier);
- spin_lock_irqsave(&die_notifier_lock, flags);
- err = notifier_chain_register(&ppc64_die_chain, nb);
- spin_unlock_irqrestore(&die_notifier_lock, flags);
- return err;
+int unregister_die_notifier(struct notifier_block *nb)
+{
+ return notifier_chain_unregister(&ppc64_die_chain, nb);
}
+EXPORT_SYMBOL(unregister_die_notifier);
/*
* Trap & Exception support
Index: linux/arch/sparc64/kernel/traps.c
===================================================================
--- linux.orig/arch/sparc64/kernel/traps.c 2005-10-28 10:02:08.000000000 +1000
+++ linux/arch/sparc64/kernel/traps.c 2005-11-03 13:45:55.954543857 +1100
@@ -43,17 +43,18 @@
#endif
struct notifier_block *sparc64die_chain;
-static DEFINE_SPINLOCK(die_notifier_lock);
int register_die_notifier(struct notifier_block *nb)
{
- int err = 0;
- unsigned long flags;
- spin_lock_irqsave(&die_notifier_lock, flags);
- err = notifier_chain_register(&sparc64die_chain, nb);
- spin_unlock_irqrestore(&die_notifier_lock, flags);
- return err;
+ return notifier_chain_register(&sparc64die_chain, nb);
}
+EXPORT_SYMBOL(register_die_notifier);
+
+int unregister_die_notifier(struct notifier_block *nb)
+{
+ return notifier_chain_unregister(&sparc64die_chain, nb);
+}
+EXPORT_SYMBOL(unregister_die_notifier);
/* When an irrecoverable trap occurs at tl > 0, the trap entry
* code logs the trap state registers at every level in the trap
Index: linux/arch/x86_64/kernel/traps.c
===================================================================
--- linux.orig/arch/x86_64/kernel/traps.c 2005-10-28 10:02:08.000000000 +1000
+++ linux/arch/x86_64/kernel/traps.c 2005-11-03 13:46:37.593324605 +1100
@@ -73,17 +73,18 @@ asmlinkage void spurious_interrupt_bug(v
asmlinkage void call_debug(void);
struct notifier_block *die_chain;
-static DEFINE_SPINLOCK(die_notifier_lock);
int register_die_notifier(struct notifier_block *nb)
{
- int err = 0;
- unsigned long flags;
- spin_lock_irqsave(&die_notifier_lock, flags);
- err = notifier_chain_register(&die_chain, nb);
- spin_unlock_irqrestore(&die_notifier_lock, flags);
- return err;
+ return notifier_chain_register(&die_chain, nb);
+}
+EXPORT_SYMBOL(register_die_notifier);
+
+int unregister_die_notifier(struct notifier_block *nb)
+{
+ return notifier_chain_unregister(&die_chain, nb);
}
+EXPORT_SYMBOL(unregister_die_notifier);
static inline void conditional_sti(struct pt_regs *regs)
{
Index: linux/include/asm-i386/kdebug.h
===================================================================
--- linux.orig/include/asm-i386/kdebug.h 2005-10-28 10:02:08.000000000 +1000
+++ linux/include/asm-i386/kdebug.h 2005-11-03 13:48:07.152245253 +1100
@@ -17,10 +17,8 @@ struct die_args {
int signr;
};
-/* Note - you should never unregister because that can race with NMIs.
- If you really want to do it first unregister - then synchronize_sched - then free.
- */
-int register_die_notifier(struct notifier_block *nb);
+extern int register_die_notifier(struct notifier_block *);
+extern int unregister_die_notifier(struct notifier_block *);
extern struct notifier_block *i386die_chain;
Index: linux/include/asm-ppc64/kdebug.h
===================================================================
--- linux.orig/include/asm-ppc64/kdebug.h 2005-10-28 10:02:08.000000000 +1000
+++ linux/include/asm-ppc64/kdebug.h 2005-11-03 13:51:34.739787840 +1100
@@ -15,12 +15,8 @@ struct die_args {
int signr;
};
-/*
- Note - you should never unregister because that can race with NMIs.
- If you really want to do it first unregister - then synchronize_sched -
- then free.
- */
-int register_die_notifier(struct notifier_block *nb);
+extern int register_die_notifier(struct notifier_block *);
+extern int unregister_die_notifier(struct notifier_block *);
extern struct notifier_block *ppc64_die_chain;
/* Grossly misnamed. */
Index: linux/include/asm-sparc64/kdebug.h
===================================================================
--- linux.orig/include/asm-sparc64/kdebug.h 2005-10-28 10:02:08.000000000 +1000
+++ linux/include/asm-sparc64/kdebug.h 2005-11-03 13:52:18.815730761 +1100
@@ -15,11 +15,8 @@ struct die_args {
int signr;
};
-/* Note - you should never unregister because that can race with NMIs.
- * If you really want to do it first unregister - then synchronize_sched
- * - then free.
- */
-int register_die_notifier(struct notifier_block *nb);
+extern int register_die_notifier(struct notifier_block *);
+extern int unregister_die_notifier(struct notifier_block *);
extern struct notifier_block *sparc64die_chain;
extern void bad_trap(struct pt_regs *, long);
Index: linux/include/asm-x86_64/kdebug.h
===================================================================
--- linux.orig/include/asm-x86_64/kdebug.h 2005-10-28 10:02:08.000000000 +1000
+++ linux/include/asm-x86_64/kdebug.h 2005-11-03 13:52:54.735573771 +1100
@@ -5,21 +5,19 @@
struct pt_regs;
-struct die_args {
+struct die_args {
struct pt_regs *regs;
const char *str;
- long err;
+ long err;
int trapnr;
int signr;
-};
+};
-/* Note - you should never unregister because that can race with NMIs.
- If you really want to do it first unregister - then synchronize_sched - then free.
- */
-int register_die_notifier(struct notifier_block *nb);
+extern int register_die_notifier(struct notifier_block *);
+extern int unregister_die_notifier(struct notifier_block *);
extern struct notifier_block *die_chain;
/* Grossly misnamed. */
-enum die_val {
+enum die_val {
DIE_OOPS = 1,
DIE_INT3,
DIE_DEBUG,
@@ -33,13 +31,13 @@ enum die_val {
DIE_CALL,
DIE_NMI_IPI,
DIE_PAGE_FAULT,
-};
-
+};
+
static inline int notify_die(enum die_val val,char *str,struct pt_regs *regs,long err,int trap, int sig)
-{
- struct die_args args = { .regs=regs, .str=str, .err=err, .trapnr=trap,.signr=sig };
- return notifier_call_chain(&die_chain, val, &args);
-}
+{
+ struct die_args args = { .regs=regs, .str=str, .err=err, .trapnr=trap,.signr=sig };
+ return notifier_call_chain(&die_chain, val, &args);
+}
extern int printk_address(unsigned long address);
extern void die(const char *,struct pt_regs *,long);
-
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