From: Colin Cross <ccross@android.com>
Date: Thu, 27 Jan 2011 23:46:20 +0000 (-0800)
Subject: ARM: vfp: Move exception address fixup into vfphw.S
X-Git-Tag: firefly_0821_release~7613^2~673
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=082fec5ea3d328ceb86a9590c5e47efedc5ea45c;p=firefly-linux-kernel-4.4.55.git

ARM: vfp: Move exception address fixup into vfphw.S

If the PC on the stack is updated in entry-armv.S,
do_undefinstr can get called after the fixup.  do_undefinstr
does its own fixup, and doing both causes the PC to point to
half way through an instruction.

Instead, do the fixup in do_vfp, where only the vfp code
can get called.

Change-Id: I6d966887adc8ed58d88bfe0cb3c0ba29213be488
Signed-off-by: Colin Cross <ccross@android.com>
---

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index e64b47dd43f6..45516a4840e3 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -492,8 +492,7 @@ __und_usr:
 	blo	__und_usr_unknown
 3:	ldrht	r0, [r4]
 	add	r2, r2, #2			@ r2 is PC + 2, make it PC + 4
-	str    	r2, [sp, #S_PC]			@ it's a 2x16bit instr, update
-	orr    	r0, r0, r5, lsl #16		@  regs->ARM_pc
+	orr    	r0, r0, r5, lsl #16
 #else
 	b	__und_usr_unknown
 #endif
diff --git a/arch/arm/vfp/entry.S b/arch/arm/vfp/entry.S
index 4fa9903b83cf..c1a978402583 100644
--- a/arch/arm/vfp/entry.S
+++ b/arch/arm/vfp/entry.S
@@ -10,7 +10,7 @@
  *
  * Basic entry code, called from the kernel's undefined instruction trap.
  *  r0  = faulted instruction
- *  r5  = faulted PC+4
+ *  r2  = faulted PC+4
  *  r9  = successful return
  *  r10 = thread_info structure
  *  lr  = failure return
@@ -26,6 +26,7 @@ ENTRY(do_vfp)
 	str	r11, [r10, #TI_PREEMPT]
 #endif
 	enable_irq
+	str	r2, [sp, #S_PC]		@ update regs->ARM_pc for Thumb 2 case
  	ldr	r4, .LCvfp
 	ldr	r11, [r10, #TI_CPU]	@ CPU number
 	add	r10, r10, #TI_VFPSTATE	@ r10 = workspace