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authorJulien Thierry <julien.thierry@arm.com>2018-09-11 10:12:05 +0100
committerRussell King <rmk+kernel@armlinux.org.uk>2018-10-05 10:51:15 +0100
commit73839798af7ebc6c8d0c9271ebbbc148700e521f (patch)
treea94c6eb00e0314eea36b34e05542b82a245f5eed /arch/arm/kernel
parent5ca451cf6ed04443774bbb7ee45332dafa42e99f (diff)
downloadlinux-73839798af7ebc6c8d0c9271ebbbc148700e521f.tar.gz
ARM: 8790/1: signal: always use __copy_to_user to save iwmmxt context
When setting a dummy iwmmxt context, create a local instance and
use __copy_to_user both cases whether iwmmxt is being used or not.
This has the benefit of disabling/enabling PAN once for the whole copy
intead of once per write.

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/signal.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 24a78cb6f031..240a30e167fd 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -77,8 +77,6 @@ static int preserve_iwmmxt_context(struct iwmmxt_sigframe __user *frame)
 		kframe->magic = IWMMXT_MAGIC;
 		kframe->size = IWMMXT_STORAGE_SIZE;
 		iwmmxt_task_copy(current_thread_info(), &kframe->storage);
-
-		err = __copy_to_user(frame, kframe, sizeof(*frame));
 	} else {
 		/*
 		 * For bug-compatibility with older kernels, some space
@@ -86,10 +84,14 @@ static int preserve_iwmmxt_context(struct iwmmxt_sigframe __user *frame)
 		 * Set the magic and size appropriately so that properly
 		 * written userspace can skip it reliably:
 		 */
-		__put_user_error(DUMMY_MAGIC, &frame->magic, err);
-		__put_user_error(IWMMXT_STORAGE_SIZE, &frame->size, err);
+		*kframe = (struct iwmmxt_sigframe) {
+			.magic = DUMMY_MAGIC,
+			.size  = IWMMXT_STORAGE_SIZE,
+		};
 	}
 
+	err = __copy_to_user(frame, kframe, sizeof(*kframe));
+
 	return err;
 }