diff options
| -rw-r--r-- | arch/i386/kernel/kprobes.c | 61 |
1 files changed, 39 insertions, 22 deletions
diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c index 137bf612141..acdcc640a72 100644 --- a/arch/i386/kernel/kprobes.c +++ b/arch/i386/kernel/kprobes.c @@ -333,17 +333,44 @@ no_kprobe: * here. When a retprobed function returns, this probe is hit and * trampoline_probe_handler() runs, calling the kretprobe's handler. */ - void kretprobe_trampoline_holder(void) + void __kprobes kretprobe_trampoline_holder(void) { - asm volatile ( ".global kretprobe_trampoline\n" + asm volatile ( ".global kretprobe_trampoline\n" "kretprobe_trampoline: \n" - "nop\n"); - } + " pushf\n" + /* skip cs, eip, orig_eax, es, ds */ + " subl $20, %esp\n" + " pushl %eax\n" + " pushl %ebp\n" + " pushl %edi\n" + " pushl %esi\n" + " pushl %edx\n" + " pushl %ecx\n" + " pushl %ebx\n" + " movl %esp, %eax\n" + " call trampoline_handler\n" + /* move eflags to cs */ + " movl 48(%esp), %edx\n" + " movl %edx, 44(%esp)\n" + /* save true return address on eflags */ + " movl %eax, 48(%esp)\n" + " popl %ebx\n" + " popl %ecx\n" + " popl %edx\n" + " popl %esi\n" + " popl %edi\n" + " popl %ebp\n" + " popl %eax\n" + /* skip eip, orig_eax, es, ds */ + " addl $16, %esp\n" + " popf\n" + " ret\n"); +} /* - * Called when we hit the probe point at kretprobe_trampoline + * Called from kretprobe_trampoline */ -int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) +fastcall void *__kprobes trampoline_handler(struct pt_regs *regs) { struct kretprobe_instance *ri = NULL; struct hlist_head *head; @@ -372,8 +399,11 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) /* another task is sharing our hash bucket */ continue; - if (ri->rp && ri->rp->handler) + if (ri->rp && ri->rp->handler){ + __get_cpu_var(current_kprobe) = &ri->rp->kp; ri->rp->handler(ri, regs); + __get_cpu_var(current_kprobe) = NULL; + } orig_ret_address = (unsigned long)ri->ret_addr; recycle_rp_inst(ri); @@ -388,18 +418,10 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) } BUG_ON(!orig_ret_address || (orig_ret_address == trampoline_address)); - regs->eip = orig_ret_address; - reset_current_kprobe(); spin_unlock_irqrestore(&kretprobe_lock, flags); - preempt_enable_no_resched(); - /* - * By returning a non-zero value, we are telling - * kprobe_handler() that we don't want the post_handler - * to run (and have re-enabled preemption) - */ - return 1; + return (void*)orig_ret_address; } /* @@ -646,12 +668,7 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) return 0; } -static struct kprobe trampoline_p = { - .addr = (kprobe_opcode_t *) &kretprobe_trampoline, - .pre_handler = trampoline_probe_handler -}; - int __init arch_init_kprobes(void) { - return register_kprobe(&trampoline_p); + return 0; } |