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Diffstat (limited to 'arch/powerpc/kernel/entry_64.S')
-rw-r--r--arch/powerpc/kernel/entry_64.S59
1 files changed, 33 insertions, 26 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 2551c0884af..2b66d53dcc5 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -172,13 +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
@@ -488,42 +493,44 @@ 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