X-Git-Url: http://pilppa.org/gitweb/?a=blobdiff_plain;f=arch%2Fpowerpc%2Fkernel%2Fentry_64.S;h=952eba6701f404c2d8ec1a69b2a6595d26250f94;hb=5a16eff86dc1194a17c69250492e820d828e3bde;hp=1a3d4de197d2bac728cc2492e3ba9565551d5717;hpb=651857a1ecaf97a8ad9d324dd2a61675c53e541e;p=linux-2.6-omap-h63xx.git

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 1a3d4de197d..952eba6701f 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -28,6 +28,7 @@
 #include <asm/asm-offsets.h>
 #include <asm/cputable.h>
 #include <asm/firmware.h>
+#include <asm/bug.h>
 
 /*
  * System calls.
@@ -171,13 +172,18 @@ syscall_error_cont:
 	stdcx.	r0,0,r1			/* to clear the reservation */
 	andi.	r6,r8,MSR_PR
 	ld	r4,_LINK(r1)
+	/*
+	 * Clear RI before restoring r13.  If we are returning to
+	 * userspace and we take an exception after restoring r13,
+	 * we end up corrupting the userspace r13 value.
+	 */
+	li	r12,MSR_RI
+	andc	r11,r10,r12
+	mtmsrd	r11,1			/* clear MSR.RI */
 	beq-	1f
 	ACCOUNT_CPU_USER_EXIT(r11, r12)
 	ld	r13,GPR13(r1)	/* only restore r13 if returning to usermode */
 1:	ld	r2,GPR2(r1)
-	li	r12,MSR_RI
-	andc	r11,r10,r12
-	mtmsrd	r11,1			/* clear MSR.RI */
 	ld	r1,GPR1(r1)
 	mtlr	r4
 	mtcr	r5
@@ -383,8 +389,11 @@ BEGIN_FTR_SECTION
 	ld	r9,PACA_SLBSHADOWPTR(r13)
 	li	r12,0
 	std	r12,SLBSHADOW_STACKESID(r9) /* Clear ESID */
+	eieio
 	std	r7,SLBSHADOW_STACKVSID(r9)  /* Save VSID */
+	eieio
 	std	r0,SLBSHADOW_STACKESID(r9)  /* Save ESID */
+	eieio
 
 	slbie	r6
 	slbie	r6		/* Workaround POWER5 < DD2.1 issue */
@@ -487,42 +496,44 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
 #endif
 	stb	r5,PACASOFTIRQEN(r13)
 
+	/* extract EE bit and use it to restore paca->hard_enabled */
 	ld	r3,_MSR(r1)
+	rldicl	r4,r3,49,63		/* r0 = (r3 >> 15) & 1 */
+	stb	r4,PACAHARDIRQEN(r13)
+
+	ld	r4,_CTR(r1)
+	ld	r0,_LINK(r1)
+	mtctr	r4
+	mtlr	r0
+	ld	r4,_XER(r1)
+	mtspr	SPRN_XER,r4
+
+	REST_8GPRS(5, r1)
+
 	andi.	r0,r3,MSR_RI
 	beq-	unrecov_restore
 
-	/* extract EE bit and use it to restore paca->hard_enabled */
-	rldicl	r4,r3,49,63		/* r0 = (r3 >> 15) & 1 */
-	stb	r4,PACAHARDIRQEN(r13)
+	stdcx.	r0,0,r1		/* to clear the reservation */
 
-	andi.	r0,r3,MSR_PR
+	/*
+	 * Clear RI before restoring r13.  If we are returning to
+	 * userspace and we take an exception after restoring r13,
+	 * we end up corrupting the userspace r13 value.
+	 */
+	mfmsr	r4
+	andc	r4,r4,r0	/* r0 contains MSR_RI here */
+	mtmsrd	r4,1
 
 	/*
 	 * r13 is our per cpu area, only restore it if we are returning to
 	 * userspace
 	 */
+	andi.	r0,r3,MSR_PR
 	beq	1f
-	ACCOUNT_CPU_USER_EXIT(r3, r4)
+	ACCOUNT_CPU_USER_EXIT(r2, r4)
 	REST_GPR(13, r1)
 1:
-	ld	r3,_CTR(r1)
-	ld	r0,_LINK(r1)
-	mtctr	r3
-	mtlr	r0
-	ld	r3,_XER(r1)
-	mtspr	SPRN_XER,r3
-
-	REST_8GPRS(5, r1)
-
-	stdcx.	r0,0,r1		/* to clear the reservation */
-
-	mfmsr	r0
-	li	r2, MSR_RI
-	andc	r0,r0,r2
-	mtmsrd	r0,1
-
-	ld	r0,_MSR(r1)
-	mtspr	SPRN_SRR1,r0
+	mtspr	SPRN_SRR1,r3
 
 	ld	r2,_CCR(r1)
 	mtcrf	0xFF,r2
@@ -538,7 +549,6 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
 	rfid
 	b	.	/* prevent speculative execution */
 
-/* Note: this must change if we start using the TIF_NOTIFY_RESUME bit */
 do_work:
 #ifdef CONFIG_PREEMPT
 	andi.	r0,r3,MSR_PR	/* Returning to user mode? */
@@ -634,19 +644,15 @@ _GLOBAL(enter_rtas)
 	li	r0,0
 	mtcr	r0
 
+#ifdef CONFIG_BUG	
 	/* There is no way it is acceptable to get here with interrupts enabled,
 	 * check it with the asm equivalent of WARN_ON
 	 */
 	lbz	r0,PACASOFTIRQEN(r13)
 1:	tdnei	r0,0
-.section __bug_table,"a"
-	.llong	1b,__LINE__ + 0x1000000, 1f, 2f
-.previous
-.section .rodata,"a"
-1:	.asciz	__FILE__
-2:	.asciz "enter_rtas"
-.previous
-
+	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING
+#endif
+	
 	/* Hard-disable interrupts */
 	mfmsr	r6
 	rldicl	r7,r6,48,1