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: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
This commit is contained in:
Julien Thierry 2018-09-11 10:12:18 +01:00 committed by Russell King
parent 73839798af
commit 3aa2df6ec2
3 changed files with 17 additions and 20 deletions

View File

@ -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

View File

@ -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)

View File

@ -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);