From 127cda1e8cc282de1ca7a9dcc3866841977b9fcc Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Tue, 8 May 2007 18:25:14 -0700 Subject: [PATCH] [SPARC64]: Optimize fault kprobe handling just like powerpc. And eliminate DIE_GPF while we're at it. Signed-off-by: David S. Miller --- arch/sparc64/kernel/kprobes.c | 11 +-------- arch/sparc64/mm/fault.c | 45 +++++++++++------------------------ include/asm-sparc64/kdebug.h | 16 ++++++++++--- include/asm-sparc64/kprobes.h | 1 + 4 files changed, 29 insertions(+), 44 deletions(-) diff --git a/arch/sparc64/kernel/kprobes.c b/arch/sparc64/kernel/kprobes.c index a44fe47a3c2b..c93a15b785fa 100644 --- a/arch/sparc64/kernel/kprobes.c +++ b/arch/sparc64/kernel/kprobes.c @@ -313,7 +313,7 @@ out: return 1; } -static int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) +int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) { struct kprobe *cur = kprobe_running(); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); @@ -403,15 +403,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, if (post_kprobe_handler(args->regs)) ret = NOTIFY_STOP; break; - case DIE_GPF: - case DIE_PAGE_FAULT: - /* kprobe_running() needs smp_processor_id() */ - preempt_disable(); - if (kprobe_running() && - kprobe_fault_handler(args->regs, args->trapnr)) - ret = NOTIFY_STOP; - preempt_enable(); - break; default: break; } diff --git a/arch/sparc64/mm/fault.c b/arch/sparc64/mm/fault.c index c32e309f7788..b582024d2199 100644 --- a/arch/sparc64/mm/fault.c +++ b/arch/sparc64/mm/fault.c @@ -32,36 +32,23 @@ #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) +static inline int notify_page_fault(struct pt_regs *regs) { - return atomic_notifier_chain_register(¬ify_page_fault_chain, nb); -} - -int unregister_page_fault_notifier(struct notifier_block *nb) -{ - return atomic_notifier_chain_unregister(¬ify_page_fault_chain, nb); -} - -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); + int ret = 0; + + /* kprobe_running() needs smp_processor_id() */ + if (!user_mode(regs)) { + preempt_disable(); + if (kprobe_running() && kprobe_fault_handler(regs, 0)) + ret = 1; + preempt_enable(); + } + 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 @@ -120,9 +107,6 @@ static void __kprobes unhandled_fault(unsigned long address, printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %016lx\n", (tsk->mm ? (unsigned long) tsk->mm->pgd : (unsigned long) tsk->active_mm->pgd)); - if (notify_die(DIE_GPF, "general protection fault", regs, - 0, 0, SIGSEGV) == NOTIFY_STOP) - return; die_if_kernel("Oops", regs); } @@ -299,8 +283,7 @@ asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs) fault_code = get_thread_fault_code(); - if (notify_page_fault(DIE_PAGE_FAULT, "page_fault", regs, - fault_code, 0, SIGSEGV) == NOTIFY_STOP) + if (notify_page_fault(regs)) return; si_code = SEGV_MAPERR; diff --git a/include/asm-sparc64/kdebug.h b/include/asm-sparc64/kdebug.h index f8032e73f384..627e3396a5f0 100644 --- a/include/asm-sparc64/kdebug.h +++ b/include/asm-sparc64/kdebug.h @@ -7,8 +7,19 @@ struct pt_regs; -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; +} extern void bad_trap(struct pt_regs *, long); @@ -20,7 +31,6 @@ enum die_val { DIE_DIE, DIE_TRAP, DIE_TRAP_TL1, - DIE_GPF, DIE_CALL, DIE_PAGE_FAULT, }; diff --git a/include/asm-sparc64/kprobes.h b/include/asm-sparc64/kprobes.h index becc38fa06c5..a331b7b0dff2 100644 --- a/include/asm-sparc64/kprobes.h +++ b/include/asm-sparc64/kprobes.h @@ -43,4 +43,5 @@ struct kprobe_ctlblk { extern int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data); +extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr); #endif /* _SPARC64_KPROBES_H */ -- 2.30.2