diff options
Diffstat (limited to 'arch/i386/kernel/kprobes.c')
| -rw-r--r-- | arch/i386/kernel/kprobes.c | 41 |
1 files changed, 23 insertions, 18 deletions
diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c index afe6505ca0b3a..d98e44b16fe20 100644 --- a/arch/i386/kernel/kprobes.c +++ b/arch/i386/kernel/kprobes.c @@ -230,20 +230,20 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs) { unsigned long *sara = (unsigned long *)®s->esp; - struct kretprobe_instance *ri; - if ((ri = get_free_rp_inst(rp)) != NULL) { - ri->rp = rp; - ri->task = current; + struct kretprobe_instance *ri; + + if ((ri = get_free_rp_inst(rp)) != NULL) { + ri->rp = rp; + ri->task = current; ri->ret_addr = (kprobe_opcode_t *) *sara; /* Replace the return addr with trampoline addr */ *sara = (unsigned long) &kretprobe_trampoline; - - add_rp_inst(ri); - } else { - rp->nmissed++; - } + add_rp_inst(ri); + } else { + rp->nmissed++; + } } /* @@ -359,7 +359,7 @@ no_kprobe: void __kprobes kretprobe_trampoline_holder(void) { asm volatile ( ".global kretprobe_trampoline\n" - "kretprobe_trampoline: \n" + "kretprobe_trampoline: \n" " pushf\n" /* skip cs, eip, orig_eax, es, ds */ " subl $20, %esp\n" @@ -395,14 +395,15 @@ no_kprobe: */ fastcall void *__kprobes trampoline_handler(struct pt_regs *regs) { - struct kretprobe_instance *ri = NULL; - struct hlist_head *head; - struct hlist_node *node, *tmp; + struct kretprobe_instance *ri = NULL; + struct hlist_head *head, empty_rp; + struct hlist_node *node, *tmp; unsigned long flags, orig_ret_address = 0; unsigned long trampoline_address =(unsigned long)&kretprobe_trampoline; + INIT_HLIST_HEAD(&empty_rp); spin_lock_irqsave(&kretprobe_lock, flags); - head = kretprobe_inst_table_head(current); + head = kretprobe_inst_table_head(current); /* * It is possible to have multiple instances associated with a given @@ -413,14 +414,14 @@ fastcall void *__kprobes trampoline_handler(struct pt_regs *regs) * We can handle this because: * - instances are always inserted at the head of the list * - when multiple return probes are registered for the same - * function, the first instance's ret_addr will point to the + * function, the first instance's ret_addr will point to the * real return address, and all the rest will point to * kretprobe_trampoline */ hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { - if (ri->task != current) + if (ri->task != current) /* another task is sharing our hash bucket */ - continue; + continue; if (ri->rp && ri->rp->handler){ __get_cpu_var(current_kprobe) = &ri->rp->kp; @@ -429,7 +430,7 @@ fastcall void *__kprobes trampoline_handler(struct pt_regs *regs) } orig_ret_address = (unsigned long)ri->ret_addr; - recycle_rp_inst(ri); + recycle_rp_inst(ri, &empty_rp); if (orig_ret_address != trampoline_address) /* @@ -444,6 +445,10 @@ fastcall void *__kprobes trampoline_handler(struct pt_regs *regs) spin_unlock_irqrestore(&kretprobe_lock, flags); + hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { + hlist_del(&ri->hlist); + kfree(ri); + } return (void*)orig_ret_address; } |