[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>

diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
index a01cf0284db2dc20b2ab7b9e6e0d299074410a49..9bb2f6241d9faeaf77c71567569baba703716912 100644 (file)
--- 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)