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[POWERPC] Minor fault path optimization

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Call the kprobes pagefault handler directly instead of going through
the complex notifier chain.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Christoph Hellwig
2007-04-30 11:56:46 +01:00
committed by Paul Mackerras
parent eb609e52d1
commit 9f90b997de
4 changed files with 30 additions and 38 deletions
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40
arch/powerpc/mm/fault.c
View File

@@ -39,37 +39,26 @@
#include <asm/kdebug.h>
#include <asm/siginfo.h>
#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)
static inline int notify_page_fault(struct pt_regs *regs)
{
return atomic_notifier_chain_register(&notify_page_fault_chain, nb);
}
int ret = 0;
int unregister_page_fault_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_unregister(&notify_page_fault_chain, nb);
}
/* kprobe_running() needs smp_processor_id() */
if (!user_mode(regs)) {
preempt_disable();
if (kprobe_running() && kprobe_fault_handler(regs, 11))
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)
{
return NOTIFY_DONE;
return 0;
}
#endif
@@ -175,8 +164,7 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
is_write = error_code & ESR_DST;
#endif /* CONFIG_4xx || CONFIG_BOOKE */
if (notify_page_fault(DIE_PAGE_FAULT, "page_fault", regs, error_code,
11, SIGSEGV) == NOTIFY_STOP)
if (notify_page_fault(regs))
return 0;
if (trap == 0x300) {