x86 user stack frame reads: switch to explicit __get_user()

rather than relying upon the magic in raw_copy_from_user()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 4 insertions, 2 deletions

diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index 2d6898c2cb64..6ad43fc44556 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -96,7 +96,8 @@ struct stack_frame_user {
 };
 
 static int
-copy_stack_frame(const void __user *fp, struct stack_frame_user *frame)
+copy_stack_frame(const struct stack_frame_user __user *fp,
+		 struct stack_frame_user *frame)
 {
 	int ret;
 
@@ -105,7 +106,8 @@ copy_stack_frame(const void __user *fp, struct stack_frame_user *frame)
 
 	ret = 1;
 	pagefault_disable();
-	if (__copy_from_user_inatomic(frame, fp, sizeof(*frame)))
+	if (__get_user(frame->next_fp, &fp->next_fp) ||
+	    __get_user(frame->ret_addr, &fp->ret_addr))
 		ret = 0;
 	pagefault_enable();