Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

[powerpc.git] / arch / powerpc / kernel / entry_64.S

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 1a3d4de..2b66d53 100644 (file)
--- 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
@@ -487,42 +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
@@ -634,19 +642,15 @@ _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