From mboxrd@z Thu Jan 1 00:00:00 1970 From: julien.thierry@arm.com (Julien Thierry) Date: Tue, 28 Aug 2018 10:08:34 +0100 Subject: [RESEND PATCH 6/8] ARM: signal: always use __copy_to_user to save iwmmxt context In-Reply-To: <1535447316-32187-1-git-send-email-julien.thierry@arm.com> References: <1535447316-32187-1-git-send-email-julien.thierry@arm.com> Message-ID: <1535447316-32187-7-git-send-email-julien.thierry@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 --- 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 76fe75d..464393d 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; } -- 1.9.1