diff options
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 59 |
1 files changed, 33 insertions, 26 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 2551c0884afc..2b66d53dcc55 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 |