From: Julien Thierry <julien.thierry@xxxxxxx>
Commit 73839798af7ebc6c8d0c9271ebbbc148700e521f upstream.
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@xxxxxxx>
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
Signed-off-by: David A. Long <dave.long@xxxxxxxxxx>
---
arch/arm/kernel/signal.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 1dc1f39825b6..b12499cc3582 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -76,8 +76,6 @@ 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
@@ -85,10 +83,14 @@ 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;
}
--
2.17.1
