[3.8.y.z extended stable] Patch "ARM: entry: move disable_irq_notrace into svc_exit" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    ARM: entry: move disable_irq_notrace into svc_exit

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.14.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 187ced522efd6ba588df9a0d3c97b128615c8421 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel at arm.linux.org.uk>
Date: Thu, 28 Mar 2013 14:36:05 +0000
Subject: ARM: entry: move disable_irq_notrace into svc_exit

commit f8f02ec25ce3eafb049feeb3abf34fcd6e338241 upstream.

All svc exit paths need IRQs off.  Rather than placing this before
every user of svc_exit, combine it into this macro.

Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
[ kamal: 3.8 stable prereq for
  e16b31b ARM: 7876/1: clear Thumb-2 IT state on exception handling ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 arch/arm/kernel/entry-armv.S   | 18 ------------------
 arch/arm/kernel/entry-header.S |  6 ++++++
 2 files changed, 6 insertions(+), 18 deletions(-)

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index a716ea9..a7de792 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -192,11 +192,6 @@ __dabt_svc:
 	svc_entry
 	mov	r2, sp
 	dabt_helper
-
-	@
-	@ IRQs off again before pulling preserved data off the stack
-	@
-	disable_irq_notrace
 	svc_exit r5				@ return from exception
  UNWIND(.fnend		)
 ENDPROC(__dabt_svc)
@@ -283,15 +278,7 @@ __und_svc_fault:
 	mov	r0, sp				@ struct pt_regs *regs
 	bl	__und_fault

-	@
-	@ IRQs off again before pulling preserved data off the stack
-	@
 __und_svc_finish:
-	disable_irq_notrace
-
-	@
-	@ restore SPSR and restart the instruction
-	@
 	ldr	r5, [sp, #S_PSR]		@ Get SVC cpsr
 	svc_exit r5				@ return from exception
  UNWIND(.fnend		)
@@ -302,11 +289,6 @@ __pabt_svc:
 	svc_entry
 	mov	r2, sp				@ regs
 	pabt_helper
-
-	@
-	@ IRQs off again before pulling preserved data off the stack
-	@
-	disable_irq_notrace
 	svc_exit r5				@ return from exception
  UNWIND(.fnend		)
 ENDPROC(__pabt_svc)
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 0bf15e5..57a1631 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -76,12 +76,15 @@
 #ifndef CONFIG_THUMB2_KERNEL
 	.macro	svc_exit, rpsr, irq = 0
 	.if	\irq != 0
+	@ IRQs already off
 #ifdef CONFIG_TRACE_IRQFLAGS
 	@ The parent context IRQs must have been enabled to get here in
 	@ the first place, so there's no point checking the PSR I bit.
 	bl	trace_hardirqs_on
 #endif
 	.else
+	@ IRQs off again before pulling preserved data off the stack
+	disable_irq_notrace
 #ifdef CONFIG_TRACE_IRQFLAGS
 	tst	\rpsr, #PSR_I_BIT
 	bleq	trace_hardirqs_on
@@ -136,12 +139,15 @@
 #else	/* CONFIG_THUMB2_KERNEL */
 	.macro	svc_exit, rpsr, irq = 0
 	.if	\irq != 0
+	@ IRQs already off
 #ifdef CONFIG_TRACE_IRQFLAGS
 	@ The parent context IRQs must have been enabled to get here in
 	@ the first place, so there's no point checking the PSR I bit.
 	bl	trace_hardirqs_on
 #endif
 	.else
+	@ IRQs off again before pulling preserved data off the stack
+	disable_irq_notrace
 #ifdef CONFIG_TRACE_IRQFLAGS
 	tst	\rpsr, #PSR_I_BIT
 	bleq	trace_hardirqs_on
--
1.8.3.2