From 33464e3b57834e161add62b499492cf43e35e54c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 4 May 2007 18:47:46 +0200 Subject: [PATCH] [S390] get rid of kprobes notifier call chain. And here's a port of the powerpc patch to get rid of the notifier chain completely to s390. It's ontop of Martins patch as that one is in mainline already. Signed-off-by: Christoph Hellwig Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/kprobes.c | 3 +-- arch/s390/mm/fault.c | 40 +++++++++++++------------------------- include/asm-s390/kdebug.h | 18 ++++++++++++++--- include/asm-s390/kprobes.h | 16 ++++----------- 4 files changed, 33 insertions(+), 44 deletions(-) diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c index 993f35381496..23c61f6d965b 100644 --- a/arch/s390/kernel/kprobes.c +++ b/arch/s390/kernel/kprobes.c @@ -516,7 +516,7 @@ 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(); @@ -603,7 +603,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, ret = NOTIFY_STOP; break; case DIE_TRAP: - case DIE_PAGE_FAULT: /* kprobe_running() needs smp_processor_id() */ preempt_disable(); if (kprobe_running() && diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 2b76a879a7b5..91f705adc3f9 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -52,38 +52,24 @@ extern int sysctl_userprocess_debug; extern void die(const char *,struct pt_regs *,long); #ifdef CONFIG_KPROBES -static ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain); -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) -{ - return atomic_notifier_chain_unregister(¬ify_page_fault_chain, nb); -} - -static int __kprobes __notify_page_fault(struct pt_regs *regs, long err) -{ - struct die_args args = { .str = "page fault", - .trapnr = 14, - .signr = SIGSEGV }; - args.regs = regs; - args.err = err; - return atomic_notifier_call_chain(¬ify_page_fault_chain, - DIE_PAGE_FAULT, &args); -} - static inline int notify_page_fault(struct pt_regs *regs, long err) { - if (unlikely(kprobe_running())) - return __notify_page_fault(regs, err); - return NOTIFY_DONE; + int ret = 0; + + /* kprobe_running() needs smp_processor_id() */ + if (!user_mode(regs)) { + preempt_disable(); + if (kprobe_running() && kprobe_fault_handler(regs, 14)) + ret = 1; + preempt_enable(); + } + + return ret; } #else static inline int notify_page_fault(struct pt_regs *regs, long err) { - return NOTIFY_DONE; + return 0; } #endif @@ -319,7 +305,7 @@ do_exception(struct pt_regs *regs, unsigned long error_code, int write) int space; int si_code; - if (notify_page_fault(regs, error_code) == NOTIFY_STOP) + if (notify_page_fault(regs, error_code)) return; tsk = current; diff --git a/include/asm-s390/kdebug.h b/include/asm-s390/kdebug.h index 1b50f89819a4..d2d7ad276148 100644 --- a/include/asm-s390/kdebug.h +++ b/include/asm-s390/kdebug.h @@ -22,8 +22,21 @@ struct die_args { */ extern int register_die_notifier(struct notifier_block *); extern int unregister_die_notifier(struct notifier_block *); -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 struct atomic_notifier_head s390die_chain; enum die_val { @@ -39,7 +52,6 @@ enum die_val { DIE_GPF, DIE_CALL, DIE_NMI_IPI, - DIE_PAGE_FAULT, }; static inline int notify_die(enum die_val val, const char *str, diff --git a/include/asm-s390/kprobes.h b/include/asm-s390/kprobes.h index b847ff0ec3fa..830fe4c4eea6 100644 --- a/include/asm-s390/kprobes.h +++ b/include/asm-s390/kprobes.h @@ -97,18 +97,10 @@ void kretprobe_trampoline(void); int is_prohibited_opcode(kprobe_opcode_t *instruction); void get_instruction_type(struct arch_specific_insn *ainsn); +int kprobe_fault_handler(struct pt_regs *regs, int trapnr); +int kprobe_exceptions_notify(struct notifier_block *self, + unsigned long val, void *data); + #define flush_insn_slot(p) do { } while (0) #endif /* _ASM_S390_KPROBES_H */ - -#ifdef CONFIG_KPROBES - -extern int kprobe_exceptions_notify(struct notifier_block *self, - unsigned long val, void *data); -#else /* !CONFIG_KPROBES */ -static inline int kprobe_exceptions_notify(struct notifier_block *self, - unsigned long val, void *data) -{ - return 0; -} -#endif -- 2.30.2