From 9f90b997de4efd5404a8c52f89c400f0f4e2d216 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 30 Apr 2007 11:56:46 +0100 Subject: [POWERPC] Minor fault path optimization Call the kprobes pagefault handler directly instead of going through the complex notifier chain. Signed-off-by: Christoph Hellwig Signed-off-by: Paul Mackerras --- arch/powerpc/mm/fault.c | 42 +++++++++++++++--------------------------- 1 file changed, 15 insertions(+), 27 deletions(-) (limited to 'arch/powerpc/mm/fault.c') diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 03aeb3a4607..a0f88026e46 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -39,37 +39,26 @@ #include #include -#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(¬ify_page_fault_chain, nb); -} - -int unregister_page_fault_notifier(struct notifier_block *nb) +#ifdef CONFIG_KPROBES +static inline int notify_page_fault(struct pt_regs *regs) { - return atomic_notifier_chain_unregister(¬ify_page_fault_chain, nb); -} + int ret = 0; + + /* 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(¬ify_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) { -- cgit v1.2.3