From bb144a85c70a65730424ad1a9dc50fef66e5cafe Mon Sep 17 00:00:00 2001 From: Prasanna S Panchamukhi Date: Tue, 6 Sep 2005 15:19:29 -0700 Subject: [PATCH] Kprobes: prevent possible race conditions ppc64 changes This patch contains the ppc64 architecture specific changes to prevent the possible race conditions. Signed-off-by: Prasanna S Panchamukhi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/ppc64/kernel/kprobes.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) (limited to 'arch/ppc64/kernel/kprobes.c') diff --git a/arch/ppc64/kernel/kprobes.c b/arch/ppc64/kernel/kprobes.c index a3d519518fb..591e4b67b5a 100644 --- a/arch/ppc64/kernel/kprobes.c +++ b/arch/ppc64/kernel/kprobes.c @@ -44,7 +44,7 @@ static struct kprobe *kprobe_prev; static unsigned long kprobe_status_prev, kprobe_saved_msr_prev; static struct pt_regs jprobe_saved_regs; -int arch_prepare_kprobe(struct kprobe *p) +int __kprobes arch_prepare_kprobe(struct kprobe *p) { int ret = 0; kprobe_opcode_t insn = *p->addr; @@ -68,27 +68,27 @@ int arch_prepare_kprobe(struct kprobe *p) return ret; } -void arch_copy_kprobe(struct kprobe *p) +void __kprobes arch_copy_kprobe(struct kprobe *p) { memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); p->opcode = *p->addr; } -void arch_arm_kprobe(struct kprobe *p) +void __kprobes arch_arm_kprobe(struct kprobe *p) { *p->addr = BREAKPOINT_INSTRUCTION; flush_icache_range((unsigned long) p->addr, (unsigned long) p->addr + sizeof(kprobe_opcode_t)); } -void arch_disarm_kprobe(struct kprobe *p) +void __kprobes arch_disarm_kprobe(struct kprobe *p) { *p->addr = p->opcode; flush_icache_range((unsigned long) p->addr, (unsigned long) p->addr + sizeof(kprobe_opcode_t)); } -void arch_remove_kprobe(struct kprobe *p) +void __kprobes arch_remove_kprobe(struct kprobe *p) { up(&kprobe_mutex); free_insn_slot(p->ainsn.insn); @@ -122,7 +122,8 @@ static inline void restore_previous_kprobe(void) kprobe_saved_msr = kprobe_saved_msr_prev; } -void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs) +void __kprobes arch_prepare_kretprobe(struct kretprobe *rp, + struct pt_regs *regs) { struct kretprobe_instance *ri; @@ -244,7 +245,7 @@ void kretprobe_trampoline_holder(void) /* * Called when the probe at kretprobe trampoline is hit */ -int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) +int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { struct kretprobe_instance *ri = NULL; struct hlist_head *head; @@ -308,7 +309,7 @@ int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) * single-stepped a copy of the instruction. The address of this * copy is p->ainsn.insn. */ -static void resume_execution(struct kprobe *p, struct pt_regs *regs) +static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) { int ret; unsigned int insn = *p->ainsn.insn; @@ -373,8 +374,8 @@ static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) /* * Wrapper routine to for handling exceptions. */ -int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, - void *data) +int __kprobes kprobe_exceptions_notify(struct notifier_block *self, + unsigned long val, void *data) { struct die_args *args = (struct die_args *)data; int ret = NOTIFY_DONE; @@ -406,7 +407,7 @@ int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, return ret; } -int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) +int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) { struct jprobe *jp = container_of(p, struct jprobe, kp); @@ -419,16 +420,16 @@ int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) return 1; } -void jprobe_return(void) +void __kprobes jprobe_return(void) { asm volatile("trap" ::: "memory"); } -void jprobe_return_end(void) +void __kprobes jprobe_return_end(void) { }; -int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) +int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) { /* * FIXME - we should ideally be validating that we got here 'cos -- cgit v1.2.3 From deac66ae454cacf942c051b86d9232af546fb187 Mon Sep 17 00:00:00 2001 From: Keshavamurthy Anil S Date: Tue, 6 Sep 2005 15:19:35 -0700 Subject: [PATCH] kprobes: fix bug when probed on task and isr functions This patch fixes a race condition where in system used to hang or sometime crash within minutes when kprobes are inserted on ISR routine and a task routine. The fix has been stress tested on i386, ia64, pp64 and on x86_64. To reproduce the problem insert kprobes on schedule() and do_IRQ() functions and you should see hang or system crash. Signed-off-by: Anil S Keshavamurthy Signed-off-by: Ananth N Mavinakayanahalli Acked-by: Prasanna S Panchamukhi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/ppc64/kernel/kprobes.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'arch/ppc64/kernel/kprobes.c') diff --git a/arch/ppc64/kernel/kprobes.c b/arch/ppc64/kernel/kprobes.c index 591e4b67b5a..7e80d49c589 100644 --- a/arch/ppc64/kernel/kprobes.c +++ b/arch/ppc64/kernel/kprobes.c @@ -102,7 +102,7 @@ static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs) regs->msr |= MSR_SE; /* single step inline if it is a trap variant */ - if (IS_TW(insn) || IS_TD(insn) || IS_TWI(insn) || IS_TDI(insn)) + if (is_trap(insn)) regs->nip = (unsigned long)p->addr; else regs->nip = (unsigned long)p->ainsn.insn; @@ -152,7 +152,9 @@ static inline int kprobe_handler(struct pt_regs *regs) Disarm the probe we just hit, and ignore it. */ p = get_kprobe(addr); if (p) { - if (kprobe_status == KPROBE_HIT_SS) { + kprobe_opcode_t insn = *p->ainsn.insn; + if (kprobe_status == KPROBE_HIT_SS && + is_trap(insn)) { regs->msr &= ~MSR_SE; regs->msr |= kprobe_saved_msr; unlock_kprobes(); @@ -192,8 +194,7 @@ static inline int kprobe_handler(struct pt_regs *regs) * trap variant, it could belong to someone else */ kprobe_opcode_t cur_insn = *addr; - if (IS_TW(cur_insn) || IS_TD(cur_insn) || - IS_TWI(cur_insn) || IS_TDI(cur_insn)) + if (is_trap(cur_insn)) goto no_kprobe; /* * The breakpoint instruction was removed right @@ -403,7 +404,7 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, default: break; } - preempt_enable(); + preempt_enable_no_resched(); return ret; } -- cgit v1.2.3