From: Julien Thierry julien.thierry@arm.com
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@arm.com Signed-off-by: Russell King rmk+kernel@armlinux.org.uk Signed-off-by: David A. Long dave.long@linaro.org --- 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; }