X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fi386%2Fkernel%2Fkprobes.c;h=af1d53344993cac32221d7209bf853bed4f5febc;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=afe6505ca0b3a78af53db084d60574540ea7361d;hpb=16c70f8c1b54b61c3b951b6fb220df250fe09b32;p=linux-2.6.git

diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c
index afe6505ca..af1d53344 100644
--- a/arch/i386/kernel/kprobes.c
+++ b/arch/i386/kernel/kprobes.c
@@ -184,7 +184,7 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p)
 void __kprobes arch_remove_kprobe(struct kprobe *p)
 {
 	mutex_lock(&kprobe_mutex);
-	free_insn_slot(p->ainsn.insn);
+	free_insn_slot(p->ainsn.insn, (p->ainsn.boostable == 1));
 	mutex_unlock(&kprobe_mutex);
 }
 
@@ -230,20 +230,20 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe *rp,
 				      struct pt_regs *regs)
 {
 	unsigned long *sara = (unsigned long *)&regs->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++;
+	}
 }
 
 /*
@@ -333,7 +333,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
 		return 1;
 
 ss_probe:
-#ifndef CONFIG_PREEMPT
+#if !defined(CONFIG_PREEMPT) || defined(CONFIG_PM)
 	if (p->ainsn.boostable == 1 && !p->post_handler){
 		/* Boost up -- we can execute copied instructions directly */
 		reset_current_kprobe();
@@ -359,10 +359,13 @@ 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"
+			/* 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"
@@ -373,10 +376,10 @@ no_kprobe:
 			"	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"
@@ -384,8 +387,8 @@ no_kprobe:
 			"	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");
 }
@@ -395,14 +398,19 @@ 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);
+	/* 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
@@ -413,23 +421,24 @@ 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;
+			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)
 			/*
@@ -444,6 +453,10 @@ 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;
 }