From: Thomas Graziadei <[email protected]>

commit 936dbf68ec7078572a583faf91eb8646b7c7b782 linux-rt-devel.

The 32bit powerpc assembler implementation of the lazy preemption
set the _TIF_PERSYSCALL_MASK on the low word. This could lead to
modprobe segfaults and a kernel panic - not syncing: Attempt to
kill init! issue.

Fixed by shifting the mask by 16 bit using andis and lis.

Signed-off-by: Thomas Graziadei <[email protected]>
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: Paul Gortmaker <[email protected]>
---
 arch/powerpc/kernel/entry_32.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index b847bcd8c49f..5c82f597d4fa 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -533,12 +533,12 @@ syscall_exit_work:
 
 1:     stw     r6,RESULT(r1)   /* Save result */
        stw     r3,GPR3(r1)     /* Update return value */
-2:     andi.   r0,r9,(_TIF_PERSYSCALL_MASK)@h
+2:     andis.  r0,r9,(_TIF_PERSYSCALL_MASK)@h
        beq     4f
 
        /* Clear per-syscall TIF flags if any are set.  */
 
-       li      r11,_TIF_PERSYSCALL_MASK@h
+       lis     r11,(_TIF_PERSYSCALL_MASK)@h
        addi    r12,r2,TI_FLAGS
 3:     lwarx   r8,0,r12
        andc    r8,r8,r11
-- 
2.7.4

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