Merge commit 'cc09f10e84d5' into kernel

Conflicts:
	src/modules/kprobe/arch/asm-arm/dbi_kprobes.c
	src/modules/kprobe/arch/asm-arm/dbi_kprobes_arm.h
	src/modules/kprobe/arch/dbi_kprobes.h
	src/modules/kprobe/dbi_kprobes.c

5 files changed, 26 insertions, 39 deletions

diff --git a/kprobe/arch/asm-arm/dbi_kprobes.c b/kprobe/arch/asm-arm/dbi_kprobes.c
index f4e1a753..399df62a 100644
--- a/kprobe/arch/asm-arm/dbi_kprobes.c
+++ b/kprobe/arch/asm-arm/dbi_kprobes.c
@@ -56,12 +56,6 @@ extern struct hlist_head kprobe_table[KPROBE_TABLE_SIZE];
 static void (*__swap_register_undef_hook)(struct undef_hook *hook);
 static void (*__swap_unregister_undef_hook)(struct undef_hook *hook);
 
-static struct kprobe trampoline_p =
-{
-	.addr = (kprobe_opcode_t *)&kretprobe_trampoline,
-	.pre_handler = trampoline_probe_handler
-};
-
 int prep_pc_dep_insn_execbuf(kprobe_opcode_t *insns, kprobe_opcode_t insn, int uregs)
 {
 	int i;
@@ -404,6 +398,19 @@ void arch_disarm_kprobe(struct kprobe *p)
 	flush_icache_range((unsigned long)p->addr, (unsigned long)p->addr + sizeof(kprobe_opcode_t));
 }
 
+void __naked kretprobe_trampoline(void)
+{
+	__asm__ __volatile__ (
+		"stmdb	sp!, {r0 - r11}		\n\t"
+		"mov	r1, sp			\n\t"
+		"mov	r0, #0			\n\t"
+		"bl	trampoline_probe_handler\n\t"
+		"mov	lr, r0			\n\t"
+		"ldmia	sp!, {r0 - r11}		\n\t"
+		"bx	lr			\n\t"
+		: : : "memory");
+}
+
 void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs)
 {
 	ri->ret_addr = (kprobe_opcode_t *)regs->ARM_lr;
@@ -436,8 +443,6 @@ static struct undef_hook undef_ho_k = {
 
 int arch_init_kprobes(void)
 {
-	int ret = 0;
-
 	// Register hooks (kprobe_handler)
 	__swap_register_undef_hook = swap_ksyms("register_undef_hook");
 	if (__swap_register_undef_hook == NULL) {
@@ -453,17 +458,12 @@ int arch_init_kprobes(void)
         }
 
 	swap_register_undef_hook(&undef_ho_k);
-	if ((ret = dbi_register_kprobe (&trampoline_p)) != 0) {
-		//dbi_unregister_jprobe(&do_exit_p, 0);
-		return ret;
-	}
 
-	return ret;
+	return 0;
 }
 
 void arch_exit_kprobes(void)
 {
-	dbi_unregister_kprobe(&trampoline_p, NULL);
 	swap_unregister_undef_hook(&undef_ho_k);
 }
 
diff --git a/kprobe/arch/asm-arm/dbi_kprobes.h b/kprobe/arch/asm-arm/dbi_kprobes.h
index 5e36549a..013e85fd 100644
--- a/kprobe/arch/asm-arm/dbi_kprobes.h
+++ b/kprobe/arch/asm-arm/dbi_kprobes.h
@@ -30,6 +30,7 @@
  */
 
 #include <linux/sched.h>
+#include <linux/compiler.h>
 
 typedef unsigned long kprobe_opcode_t;
 
@@ -508,7 +509,7 @@ void save_previous_kprobe(struct kprobe_ctlblk *kcb, struct kprobe *cur_p);
 void restore_previous_kprobe(struct kprobe_ctlblk *kcb);
 void set_current_kprobe(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb);
 
-void kretprobe_trampoline(void);
+void __naked kretprobe_trampoline(void);
 
 int arch_init_kprobes(void);
 void arch_exit_kprobes(void);
diff --git a/kprobe/arch/asm-arm/trampoline_arm.S b/kprobe/arch/asm-arm/trampoline_arm.S
index 73199c9c..5b4c7bc1 100644
--- a/kprobe/arch/asm-arm/trampoline_arm.S
+++ b/kprobe/arch/asm-arm/trampoline_arm.S
@@ -4,14 +4,6 @@
  * 	- When the probed function returns, this probe
  * 		causes the handlers to fire
  */
-		.global kretprobe_trampoline
-
-kretprobe_trampoline:
-		nop
-		nop
-		mov pc, r14
-
-
 
 		.global gen_insn_execbuf
 gen_insn_execbuf:
diff --git a/kprobe/arch/asm-arm/trampoline_arm.h b/kprobe/arch/asm-arm/trampoline_arm.h
index 1114d73c..3b35f2ff 100644
--- a/kprobe/arch/asm-arm/trampoline_arm.h
+++ b/kprobe/arch/asm-arm/trampoline_arm.h
@@ -1,7 +1,6 @@
 #ifndef __ASM_ARM_TRAMPOLINE_ARM_H
 #define __ASM_ARM_TRAMPOLINE_ARM_H
 
-void kretprobe_trampoline(void);
 void gen_insn_execbuf(void);
 void pc_dep_insn_execbuf(void);
 
diff --git a/kprobe/dbi_kprobes.c b/kprobe/dbi_kprobes.c
index 7bc03f5d..208d88e2 100644
--- a/kprobe/dbi_kprobes.c
+++ b/kprobe/dbi_kprobes.c
@@ -648,7 +648,10 @@ int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
 	unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline;
 
 	struct kretprobe *crp = NULL;
-	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+	struct kprobe_ctlblk *kcb;
+
+	preempt_disable();
+	kcb = get_kprobe_ctlblk();
 
 	spin_lock_irqsave(&kretprobe_lock, flags);
 
@@ -702,11 +705,6 @@ int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
 	}
 	kretprobe_assert(ri, orig_ret_address, trampoline_address);
 
-#ifdef CONFIG_ARM
-	regs->ARM_lr = orig_ret_address;
-	regs->ARM_pc = orig_ret_address;
-#endif
-
 	if (kcb->kprobe_status == KPROBE_REENTER) {
 		restore_previous_kprobe(kcb);
 	} else {
@@ -714,6 +712,7 @@ int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
 	}
 
 	spin_unlock_irqrestore(&kretprobe_lock, flags);
+	preempt_enable_no_resched();
 
 	/*
 	 * By returning a non-zero value, we are telling
@@ -721,11 +720,7 @@ int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
 	 * to run (and have re-enabled preemption)
 	 */
 
-#if defined (CONFIG_X86)
 	return (int)orig_ret_address;
-#elif defined (CONFIG_ARM)
-	return 1;
-#endif
 }
 
 struct kretprobe *sched_rp;
@@ -843,13 +838,13 @@ void dbi_unregister_kretprobe(struct kretprobe *rp)
 	if ((unsigned long)rp->kp.addr == sched_addr)
 		sched_rp = NULL;
 
-	while ((ri = get_used_rp_inst(rp)) != NULL) {
-		if (dbi_disarm_krp_inst(ri) == 0)
-			recycle_rp_inst(ri);
-		else
-			panic("%s (%d/%d): cannot disarm krp instance (%08lx)",
+	while ((ri = get_used_rp_inst (rp)) != NULL) {
+		if (!dbi_disarm_krp_inst(ri)) {
+			printk("%s (%d/%d): cannot disarm krp instance (%08lx)\n",
 					ri->task->comm, ri->task->tgid, ri->task->pid,
 					(unsigned long)rp->kp.addr);
+		}
+		recycle_rp_inst(ri);
 	}
 
 	spin_unlock_irqrestore(&kretprobe_lock, flags);