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From: David Long <dave.long@linaro.org>
To: stable@vger.kernel.org,
	Russell King - ARM Linux <linux@armlinux.org.uk>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Julien Thierry <julien.thierry@arm.com>,
	Tony Lindgren <tony@atomide.com>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Greg KH <gregkh@linuxfoundation.org>,
	Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>,
	Mark Brown <broonie@kernel.org>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 4.19 03/17] ARM: 8791/1: vfp: use __copy_to_user() when saving VFP state
Date: Wed, 13 Feb 2019 16:32:09 -0500	[thread overview]
Message-ID: <20190213213223.916-4-dave.long@linaro.org> (raw)
In-Reply-To: <20190213213223.916-1-dave.long@linaro.org>

From: Julien Thierry <julien.thierry@arm.com>

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>
---
 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 9b37b6ab27fe..8f55dc520a3e 100644
--- a/arch/arm/include/asm/thread_info.h
+++ b/arch/arm/include/asm/thread_info.h
@@ -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
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 464393d241e1..1e2ecfe080bb 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -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)
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index dc7e6b50ef67..2b287d0d6bc2 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -553,12 +553,11 @@ 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);
@@ -567,22 +566,19 @@ 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);
-- 
2.17.1


  parent reply	other threads:[~2019-02-13 21:32 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-13 21:32 [PATCH 4.19 00/17] V4.19 backport of more 32-bit arm spectre patches David Long
2019-02-13 21:32 ` [PATCH 4.19 01/17] ARM: 8789/1: signal: copy registers using __copy_to_user() David Long
2019-02-13 21:32 ` [PATCH 4.19 02/17] ARM: 8790/1: signal: always use __copy_to_user to save iwmmxt context David Long
2019-02-13 21:32 ` David Long [this message]
2019-02-13 21:32 ` [PATCH 4.19 04/17] ARM: 8792/1: oabi-compat: copy oabi events using __copy_to_user() David Long
2019-02-13 21:32 ` [PATCH 4.19 05/17] ARM: 8793/1: signal: replace __put_user_error with __put_user David Long
2019-02-13 21:32 ` [PATCH 4.19 06/17] ARM: 8794/1: uaccess: Prevent speculative use of the current addr_limit David Long
2019-02-13 21:32 ` [PATCH 4.19 07/17] ARM: 8795/1: spectre-v1.1: use put_user() for __put_user() David Long
2019-02-13 21:32 ` [PATCH 4.19 08/17] ARM: 8796/1: spectre-v1,v1.1: provide helpers for address sanitization David Long
2019-02-13 21:32 ` [PATCH 4.19 09/17] ARM: 8797/1: spectre-v1.1: harden __copy_to_user David Long
2019-02-13 21:32 ` [PATCH 4.19 10/17] ARM: 8810/1: vfp: Fix wrong assignement to ufp_exc David Long
2019-02-13 21:32 ` [PATCH 4.19 11/17] ARM: make lookup_processor_type() non-__init David Long
2019-02-13 21:32 ` [PATCH 4.19 12/17] ARM: split out processor lookup David Long
2019-02-13 21:32 ` [PATCH 4.19 13/17] ARM: clean up per-processor check_bugs method call David Long
2019-02-13 21:32 ` [PATCH 4.19 14/17] ARM: add PROC_VTABLE and PROC_TABLE macros David Long
2019-02-13 21:32 ` [PATCH 4.19 15/17] ARM: spectre-v2: per-CPU vtables to work around big.Little systems David Long
2019-02-13 21:32 ` [PATCH 4.19 16/17] ARM: ensure that processor vtables is not lost after boot David Long
2019-02-13 21:32 ` [PATCH 4.19 17/17] ARM: fix the cockup in the previous patch David Long
2019-02-14  8:50 ` [PATCH 4.19 00/17] V4.19 backport of more 32-bit arm spectre patches Julien Thierry
2019-02-17 19:20 ` Sasha Levin

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