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-rw-r--r--arch/powerpc/kernel/entry_32.S47
1 files changed, 41 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index ead5016..af37528 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -831,19 +831,56 @@ restore_user:
bnel- load_dbcr0
#endif
-#ifdef CONFIG_PREEMPT
b restore
/* N.B. the only way to get here is from the beq following ret_from_except. */
resume_kernel:
- /* check current_thread_info->preempt_count */
+ /* check current_thread_info, _TIF_EMULATE_STACK_STORE */
CURRENT_THREAD_INFO(r9, r1)
+ lwz r8,TI_FLAGS(r9)
+ andis. r8,r8,_TIF_EMULATE_STACK_STORE@h
+ beq+ 1f
+
+ addi r8,r1,INT_FRAME_SIZE /* Get the kprobed function entry */
+
+ lwz r3,GPR1(r1)
+ subi r3,r3,INT_FRAME_SIZE /* dst: Allocate a trampoline exception frame */
+ mr r4,r1 /* src: current exception frame */
+ mr r1,r3 /* Reroute the trampoline frame to r1 */
+
+ /* Copy from the original to the trampoline. */
+ li r5,INT_FRAME_SIZE/4 /* size: INT_FRAME_SIZE */
+ li r6,0 /* start offset: 0 */
+ mtctr r5
+2: lwzx r0,r6,r4
+ stwx r0,r6,r3
+ addi r6,r6,4
+ bdnz 2b
+
+ /* Do real store operation to complete stwu */
+ lwz r5,GPR1(r1)
+ stw r8,0(r5)
+
+ /* Clear _TIF_EMULATE_STACK_STORE flag */
+ lis r11,_TIF_EMULATE_STACK_STORE@h
+ addi r5,r9,TI_FLAGS
+0: lwarx r8,0,r5
+ andc r8,r8,r11
+#ifdef CONFIG_IBM405_ERR77
+ dcbt 0,r5
+#endif
+ stwcx. r8,0,r5
+ bne- 0b
+1:
+
+#ifdef CONFIG_PREEMPT
+ /* check current_thread_info->preempt_count */
lwz r0,TI_PREEMPT(r9)
cmpwi 0,r0,0 /* if non-zero, just restore regs and return */
bne restore
- lwz r0,TI_FLAGS(r9)
- andi. r0,r0,_TIF_NEED_RESCHED
+ andi. r8,r8,_TIF_NEED_RESCHED
beq+ restore
+ lwz r3,_MSR(r1)
andi. r0,r3,MSR_EE /* interrupts off? */
beq restore /* don't schedule if so */
#ifdef CONFIG_TRACE_IRQFLAGS
@@ -864,8 +901,6 @@ resume_kernel:
*/
bl trace_hardirqs_on
#endif
-#else
-resume_kernel:
#endif /* CONFIG_PREEMPT */
/* interrupts are hard-disabled at this point */
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