1 files changed, 11 insertions, 10 deletions

diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c
index a5b64ab4cd6e..bff89dfe3619 100644
--- a/arch/x86/oprofile/backtrace.c
+++ b/arch/x86/oprofile/backtrace.c
@@ -11,10 +11,11 @@
 #include <linux/oprofile.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
+#include <linux/compat.h>
+#include <linux/uaccess.h>
+
 #include <asm/ptrace.h>
-#include <asm/uaccess.h>
 #include <asm/stacktrace.h>
-#include <linux/compat.h>
 
 static int backtrace_stack(void *data, char *name)
 {
@@ -40,13 +41,13 @@ static struct stacktrace_ops backtrace_ops = {
 static struct stack_frame_ia32 *
 dump_user_backtrace_32(struct stack_frame_ia32 *head)
 {
+        /* Also check accessibility of one struct frame_head beyond: */
         struct stack_frame_ia32 bufhead[2];
         struct stack_frame_ia32 *fp;
+        unsigned long bytes;
 
-        /* Also check accessibility of one struct frame_head beyond */
-        if (!access_ok(VERIFY_READ, head, sizeof(bufhead)))
-                return NULL;
-        if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
+        bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
+        if (bytes != sizeof(bufhead))
                 return NULL;
 
         fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame);
@@ -87,12 +88,12 @@ x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
 
 static struct stack_frame *dump_user_backtrace(struct stack_frame *head)
 {
+        /* Also check accessibility of one struct frame_head beyond: */
         struct stack_frame bufhead[2];
+        unsigned long bytes;
 
-        /* Also check accessibility of one struct stack_frame beyond */
-        if (!access_ok(VERIFY_READ, head, sizeof(bufhead)))
-                return NULL;
-        if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
+        bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
+        if (bytes != sizeof(bufhead))
                 return NULL;
 
         oprofile_add_trace(bufhead[0].return_address);