Commit 576fe0bd authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Tony Luck

[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: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 17028c5c
...@@ -820,7 +820,7 @@ out: ...@@ -820,7 +820,7 @@ out:
return 1; 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 *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
...@@ -904,13 +904,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, ...@@ -904,13 +904,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
if (post_kprobes_handler(args->regs)) if (post_kprobes_handler(args->regs))
ret = NOTIFY_STOP; ret = NOTIFY_STOP;
break; 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: default:
break; break;
} }
......
...@@ -19,36 +19,24 @@ ...@@ -19,36 +19,24 @@
extern void die (char *, struct pt_regs *, long); extern void die (char *, struct pt_regs *, long);
#ifdef CONFIG_KPROBES #ifdef CONFIG_KPROBES
ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain); static inline int notify_page_fault(struct pt_regs *regs, int trap)
/* 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)
{ {
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, return ret;
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);
} }
#else #else
static inline int notify_page_fault(enum die_val val, const char *str, static inline int notify_page_fault(struct pt_regs *regs, int trap)
struct pt_regs *regs, long err, int trap, int sig)
{ {
return NOTIFY_DONE; return 0;
} }
#endif #endif
...@@ -117,8 +105,7 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re ...@@ -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 * This is to handle the kprobes on user space access instructions
*/ */
if (notify_page_fault(DIE_PAGE_FAULT, "page fault", regs, code, TRAP_BRKPT, if (notify_page_fault(regs, TRAP_BRKPT))
SIGSEGV) == NOTIFY_STOP)
return; return;
down_read(&mm->mmap_sem); down_read(&mm->mmap_sem);
......
...@@ -28,14 +28,24 @@ ...@@ -28,14 +28,24 @@
*/ */
#include <linux/notifier.h> #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 { enum die_val {
DIE_BREAK = 1, DIE_BREAK = 1,
DIE_FAULT, DIE_FAULT,
DIE_OOPS, DIE_OOPS,
DIE_PAGE_FAULT,
DIE_MACHINE_HALT, DIE_MACHINE_HALT,
DIE_MACHINE_RESTART, DIE_MACHINE_RESTART,
DIE_MCA_MONARCH_ENTER, DIE_MCA_MONARCH_ENTER,
......
...@@ -120,6 +120,7 @@ struct arch_specific_insn { ...@@ -120,6 +120,7 @@ struct arch_specific_insn {
unsigned short slot; unsigned short slot;
}; };
extern int kprobes_fault_handler(struct pt_regs *regs, int trapnr);
extern int kprobe_exceptions_notify(struct notifier_block *self, extern int kprobe_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data); unsigned long val, void *data);
......
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