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authorChristoph Hellwig <hch@lst.de>2007-05-16 14:52:19 +0200
committerTony Luck <tony.luck@intel.com>2007-05-16 09:00:51 -0700
commit576fe0bd7e52dce7afb6b9b2450744555b2eb53a (patch)
treeacf2a5f8d7f7906cfa2da9bf53a74d8e3fcd42bb
parent17028c5c91580036eb41da2fad292965fa3b9a7d (diff)
downloadblackbird-op-linux-576fe0bd7e52dce7afb6b9b2450744555b2eb53a.tar.gz
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[IA64] optimize pagefaults a little
Get rid of the notifier list and call the kprobes code directly if compiled in. This mirrors the changes that recently went into powerpc, s390 and sparc64. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Tony Luck <tony.luck@intel.com>
-rw-r--r--arch/ia64/kernel/kprobes.c9
-rw-r--r--arch/ia64/mm/fault.c41
-rw-r--r--include/asm-ia64/kdebug.h16
-rw-r--r--include/asm-ia64/kprobes.h1
4 files changed, 29 insertions, 38 deletions
diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c
index be81fe42d80b..5bc46f151344 100644
--- a/arch/ia64/kernel/kprobes.c
+++ b/arch/ia64/kernel/kprobes.c
@@ -820,7 +820,7 @@ out:
return 1;
}
-static int __kprobes kprobes_fault_handler(struct pt_regs *regs, int trapnr)
+int __kprobes kprobes_fault_handler(struct pt_regs *regs, int trapnr)
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
@@ -904,13 +904,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
if (post_kprobes_handler(args->regs))
ret = NOTIFY_STOP;
break;
- case DIE_PAGE_FAULT:
- /* kprobe_running() needs smp_processor_id() */
- preempt_disable();
- if (kprobe_running() &&
- kprobes_fault_handler(args->regs, args->trapnr))
- ret = NOTIFY_STOP;
- preempt_enable();
default:
break;
}
diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c
index 21658e02116c..b87f785c2416 100644
--- a/arch/ia64/mm/fault.c
+++ b/arch/ia64/mm/fault.c
@@ -19,36 +19,24 @@
extern void die (char *, struct pt_regs *, long);
#ifdef CONFIG_KPROBES
-ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
-
-/* Hook to register for page fault notifications */
-int register_page_fault_notifier(struct notifier_block *nb)
-{
- return atomic_notifier_chain_register(&notify_page_fault_chain, nb);
-}
-
-int unregister_page_fault_notifier(struct notifier_block *nb)
+static inline int notify_page_fault(struct pt_regs *regs, int trap)
{
- return atomic_notifier_chain_unregister(&notify_page_fault_chain, nb);
-}
+ int ret = 0;
+
+ if (!user_mode(regs)) {
+ /* kprobe_running() needs smp_processor_id() */
+ preempt_disable();
+ if (kprobe_running() && kprobes_fault_handler(regs, trap))
+ ret = 1;
+ preempt_enable();
+ }
-static inline int notify_page_fault(enum die_val val, const 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 atomic_notifier_call_chain(&notify_page_fault_chain, val, &args);
+ return ret;
}
#else
-static inline int notify_page_fault(enum die_val val, const char *str,
- struct pt_regs *regs, long err, int trap, int sig)
+static inline int notify_page_fault(struct pt_regs *regs, int trap)
{
- return NOTIFY_DONE;
+ return 0;
}
#endif
@@ -117,8 +105,7 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
/*
* This is to handle the kprobes on user space access instructions
*/
- if (notify_page_fault(DIE_PAGE_FAULT, "page fault", regs, code, TRAP_BRKPT,
- SIGSEGV) == NOTIFY_STOP)
+ if (notify_page_fault(regs, TRAP_BRKPT))
return;
down_read(&mm->mmap_sem);
diff --git a/include/asm-ia64/kdebug.h b/include/asm-ia64/kdebug.h
index ba211e011a1d..320cd8e754ea 100644
--- a/include/asm-ia64/kdebug.h
+++ b/include/asm-ia64/kdebug.h
@@ -28,14 +28,24 @@
*/
#include <linux/notifier.h>
-extern int register_page_fault_notifier(struct notifier_block *);
-extern int unregister_page_fault_notifier(struct notifier_block *);
+/*
+ * These are only here because kprobes.c wants them to implement a
+ * blatant layering violation. Will hopefully go away soon once all
+ * architectures are updated.
+ */
+static inline int register_page_fault_notifier(struct notifier_block *nb)
+{
+ return 0;
+}
+static inline int unregister_page_fault_notifier(struct notifier_block *nb)
+{
+ return 0;
+}
enum die_val {
DIE_BREAK = 1,
DIE_FAULT,
DIE_OOPS,
- DIE_PAGE_FAULT,
DIE_MACHINE_HALT,
DIE_MACHINE_RESTART,
DIE_MCA_MONARCH_ENTER,
diff --git a/include/asm-ia64/kprobes.h b/include/asm-ia64/kprobes.h
index 2abc98b336f3..6382e52ec227 100644
--- a/include/asm-ia64/kprobes.h
+++ b/include/asm-ia64/kprobes.h
@@ -120,6 +120,7 @@ struct arch_specific_insn {
unsigned short slot;
};
+extern int kprobes_fault_handler(struct pt_regs *regs, int trapnr);
extern int kprobe_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data);
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