4.9-stable review patch. If anyone has any objections, please let me know.
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Commit 3aa2df6ec2ca6bc143a65351cca4266d03a8bc41 upstream.
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 Signed-off-by: David A. Long dave.long@linaro.org Reviewed-by: Julien Thierry julien.thierry@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm/include/asm/thread_info.h | 4 ++-- arch/arm/kernel/signal.c | 13 +++++++------ arch/arm/vfp/vfpmodule.c | 20 ++++++++------------ 3 files changed, 17 insertions(+), 20 deletions(-)
diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h index 57d2ad9c75ca..df8420672c7e 100644 --- a/arch/arm/include/asm/thread_info.h +++ b/arch/arm/include/asm/thread_info.h @@ -124,8 +124,8 @@ 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 diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index fbb325ff8acc..135b1a8e12eb 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -94,17 +94,18 @@ static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame)
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(struct vfp_sigframe __user *auxp) diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index 8e5e97989fda..df3fa52c0aa3 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -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);