1 files changed, 8 insertions, 39 deletions

diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
index a01cf0284db2..86783efa24ee 100644
--- a/arch/s390/kernel/kprobes.c
+++ b/arch/s390/kernel/kprobes.c
@@ -25,9 +25,9 @@
 #include <linux/preempt.h>
 #include <linux/stop_machine.h>
 #include <linux/kdebug.h>
+#include <linux/uaccess.h>
 #include <asm/cacheflush.h>
 #include <asm/sections.h>
-#include <asm/uaccess.h>
 #include <linux/module.h>
 
 DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
@@ -154,66 +154,35 @@ void __kprobes get_instruction_type(struct arch_specific_insn *ainsn)
 
 static int __kprobes swap_instruction(void *aref)
 {
+	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+	unsigned long status = kcb->kprobe_status;
 	struct ins_replace_args *args = aref;
-	u32 *addr;
-	u32 instr;
-	int err = -EFAULT;
+	int rc;
 
-	/*
-	 * Text segment is read-only, hence we use stura to bypass dynamic
-	 * address translation to exchange the instruction. Since stura
-	 * always operates on four bytes, but we only want to exchange two
-	 * bytes do some calculations to get things right. In addition we
-	 * shall not cross any page boundaries (vmalloc area!) when writing
-	 * the new instruction.
-	 */
-	addr = (u32 *)((unsigned long)args->ptr & -4UL);
-	if ((unsigned long)args->ptr & 2)
-		instr = ((*addr) & 0xffff0000) | args->new;
-	else
-		instr = ((*addr) & 0x0000ffff) | args->new << 16;
-
-	asm volatile(
-		"	lra	%1,0(%1)\n"
-		"0:	stura	%2,%1\n"
-		"1:	la	%0,0\n"
-		"2:\n"
-		EX_TABLE(0b,2b)
-		: "+d" (err)
-		: "a" (addr), "d" (instr)
-		: "memory", "cc");
-
-	return err;
+	kcb->kprobe_status = KPROBE_SWAP_INST;
+	rc = probe_kernel_write(args->ptr, &args->new, sizeof(args->new));
+	kcb->kprobe_status = status;
+	return rc;
 }
 
 void __kprobes arch_arm_kprobe(struct kprobe *p)
 {
-	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-	unsigned long status = kcb->kprobe_status;
 	struct ins_replace_args args;
 
 	args.ptr = p->addr;
 	args.old = p->opcode;
 	args.new = BREAKPOINT_INSTRUCTION;
-
-	kcb->kprobe_status = KPROBE_SWAP_INST;
 	stop_machine(swap_instruction, &args, NULL);
-	kcb->kprobe_status = status;
 }
 
 void __kprobes arch_disarm_kprobe(struct kprobe *p)
 {
-	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-	unsigned long status = kcb->kprobe_status;
 	struct ins_replace_args args;
 
 	args.ptr = p->addr;
 	args.old = BREAKPOINT_INSTRUCTION;
 	args.new = p->opcode;
-
-	kcb->kprobe_status = KPROBE_SWAP_INST;
 	stop_machine(swap_instruction, &args, NULL);
-	kcb->kprobe_status = status;
 }
 
 void __kprobes arch_remove_kprobe(struct kprobe *p)