From: Christoph Hellwig Date: Wed, 16 May 2007 12:52:19 +0000 (+0200) Subject: [IA64] optimize pagefaults a little X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=576fe0bd7e52dce7afb6b9b2450744555b2eb53a;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git [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 Signed-off-by: Tony Luck --- 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(¬ify_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(¬ify_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(¬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, 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 -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);