Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3aa2df6e authored by Julien Thierry's avatar Julien Thierry Committed by Russell King
Browse files

ARM: 8791/1: vfp: use __copy_to_user() when saving VFP state 



Use __copy_to_user() rather than __put_user_error() for individual
members when saving VFP state.
This has the benefit of disabling/enabling PAN once per copied struct
intead of once per write.

Signed-off-by: default avatarJulien Thierry <julien.thierry@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
parent 73839798

arch/arm/include/asm/thread_info.h

+2 −2
Original line number Diff line number Diff line
@@ -121,8 +121,8 @@ extern void vfp_flush_hwstate(struct thread_info *); 
struct user_vfp;

struct user_vfp_exc;



extern int vfp_preserve_user_clear_hwstate(struct user_vfp __user *,

					   struct user_vfp_exc __user *);

extern int vfp_preserve_user_clear_hwstate(struct user_vfp *,

					   struct user_vfp_exc *);

extern int vfp_restore_user_hwstate(struct user_vfp *,

				    struct user_vfp_exc *);

#endif

arch/arm/kernel/signal.c

+7 −6
Original line number Diff line number Diff line
@@ -137,17 +137,18 @@ static int restore_iwmmxt_context(char __user **auxp) 


static int preserve_vfp_context(struct vfp_sigframe __user *frame)

{

	const unsigned long magic = VFP_MAGIC;

	const unsigned long size = VFP_STORAGE_SIZE;

	struct vfp_sigframe kframe;

	int err = 0;



	__put_user_error(magic, &frame->magic, err);

	__put_user_error(size, &frame->size, err);

	memset(&kframe, 0, sizeof(kframe));

	kframe.magic = VFP_MAGIC;

	kframe.size = VFP_STORAGE_SIZE;



	err = vfp_preserve_user_clear_hwstate(&kframe.ufp, &kframe.ufp_exc);

	if (err)

		return -EFAULT;

		return err;



	return vfp_preserve_user_clear_hwstate(&frame->ufp, &frame->ufp_exc);

	return __copy_to_user(frame, &kframe, sizeof(kframe));

}



static int restore_vfp_context(char __user **auxp)

arch/arm/vfp/vfpmodule.c

+8 −12
Original line number Diff line number Diff line
@@ -554,12 +554,11 @@ void vfp_flush_hwstate(struct thread_info *thread) 
 * Save the current VFP state into the provided structures and prepare

 * for entry into a new function (signal handler).

 */

int vfp_preserve_user_clear_hwstate(struct user_vfp __user *ufp,

				    struct user_vfp_exc __user *ufp_exc)

int vfp_preserve_user_clear_hwstate(struct user_vfp *ufp,

				    struct user_vfp_exc *ufp_exc)

{

	struct thread_info *thread = current_thread_info();

	struct vfp_hard_struct *hwstate = &thread->vfpstate.hard;

	int err = 0;



	/* Ensure that the saved hwstate is up-to-date. */

	vfp_sync_hwstate(thread);
@@ -568,22 +567,19 @@ int vfp_preserve_user_clear_hwstate(struct user_vfp __user *ufp, 
	 * Copy the floating point registers. There can be unused

	 * registers see asm/hwcap.h for details.

	 */

	err |= __copy_to_user(&ufp->fpregs, &hwstate->fpregs,

			      sizeof(hwstate->fpregs));

	memcpy(&ufp->fpregs, &hwstate->fpregs, sizeof(hwstate->fpregs));



	/*

	 * Copy the status and control register.

	 */

	__put_user_error(hwstate->fpscr, &ufp->fpscr, err);

	ufp->fpscr = hwstate->fpscr;



	/*

	 * Copy the exception registers.

	 */

	__put_user_error(hwstate->fpexc, &ufp_exc->fpexc, err);

	__put_user_error(hwstate->fpinst, &ufp_exc->fpinst, err);

	__put_user_error(hwstate->fpinst2, &ufp_exc->fpinst2, err);



	if (err)

		return -EFAULT;

	ufp_exc->fpexc = hwstate->fpexc;

	ufp_exc->fpinst = hwstate->fpinst;

	ufp_exc->fpinst2 = ufp_exc->fpinst2;



	/* Ensure that VFP is disabled. */

	vfp_flush_hwstate(thread);