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++;
+ }
}
/*
int ret = 0;
kprobe_opcode_t *addr;
struct kprobe_ctlblk *kcb;
-#ifdef CONFIG_PREEMPT
- unsigned pre_preempt_count = preempt_count();
-#else
- unsigned pre_preempt_count = 1;
-#endif
addr = (kprobe_opcode_t *)(regs->eip - sizeof(kprobe_opcode_t));
return 1;
ss_probe:
- if (pre_preempt_count && p->ainsn.boostable == 1 && !p->post_handler){
+#ifndef CONFIG_PREEMPT
+ if (p->ainsn.boostable == 1 && !p->post_handler){
/* Boost up -- we can execute copied instructions directly */
reset_current_kprobe();
regs->eip = (unsigned long)p->ainsn.insn;
preempt_enable_no_resched();
return 1;
}
+#endif
prepare_singlestep(p, regs);
kcb->kprobe_status = KPROBE_HIT_SS;
return 1;
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"
+ /* skip cs, eip, orig_eax */
+ " subl $12, %esp\n"
+ " pushl %gs\n"
+ " pushl %ds\n"
+ " pushl %es\n"
" pushl %eax\n"
" pushl %ebp\n"
" pushl %edi\n"
" movl %esp, %eax\n"
" call trampoline_handler\n"
/* move eflags to cs */
- " movl 48(%esp), %edx\n"
- " movl %edx, 44(%esp)\n"
+ " movl 52(%esp), %edx\n"
+ " movl %edx, 48(%esp)\n"
/* save true return address on eflags */
- " movl %eax, 48(%esp)\n"
+ " movl %eax, 52(%esp)\n"
" popl %ebx\n"
" popl %ecx\n"
" popl %edx\n"
" popl %edi\n"
" popl %ebp\n"
" popl %eax\n"
- /* skip eip, orig_eax, es, ds */
- " addl $16, %esp\n"
+ /* skip eip, orig_eax, es, ds, gs */
+ " addl $20, %esp\n"
" popf\n"
" ret\n");
}
*/
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);
+ /* fixup registers */
+ regs->xcs = __KERNEL_CS;
+ regs->eip = trampoline_address;
+ regs->orig_eax = 0xffffffff;
/*
* It is possible to have multiple instances associated with a given
* 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;
+ get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
ri->rp->handler(ri, regs);
__get_cpu_var(current_kprobe) = NULL;
}
orig_ret_address = (unsigned long)ri->ret_addr;
- recycle_rp_inst(ri);
+ recycle_rp_inst(ri, &empty_rp);
if (orig_ret_address != trampoline_address)
/*
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;
}