[S390] kprobes: use probe_kernel_write

Use proble_kernel_write() to patch the kernel.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 2 insertions, 29 deletions

diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
index a01cf0284db2..9bb2f6241d9f 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;
@@ -155,35 +155,8 @@ void __kprobes get_instruction_type(struct arch_specific_insn *ainsn)
 static int __kprobes swap_instruction(void *aref)
 {
         struct ins_replace_args *args = aref;
-        u32 *addr;
-        u32 instr;
-        int err = -EFAULT;
 
-        /*
-         * 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;
+        return probe_kernel_write(args->ptr, &args->new, sizeof(args->new));
 }
 
 void __kprobes arch_arm_kprobe(struct kprobe *p)