diff options
| -rw-r--r-- | arch/parisc/kernel/syscall.S | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S index 40190dbecdc0..deec1f8465e5 100644 --- a/arch/parisc/kernel/syscall.S +++ b/arch/parisc/kernel/syscall.S @@ -106,8 +106,6 @@ linux_gateway_entry: mtsp %r0,%sr4 /* get kernel space into sr4 */ mtsp %r0,%sr5 /* get kernel space into sr5 */ mtsp %r0,%sr6 /* get kernel space into sr6 */ - mfsp %sr7,%r1 /* save user sr7 */ - mtsp %r1,%sr3 /* and store it in sr3 */ #ifdef CONFIG_64BIT /* for now we can *always* set the W bit on entry to the syscall @@ -133,6 +131,14 @@ linux_gateway_entry: depdi 0, 31, 32, %r21 1: #endif + + /* We use a rsm/ssm pair to prevent sr3 from being clobbered + * by external interrupts. + */ + mfsp %sr7,%r1 /* save user sr7 */ + rsm PSW_SM_I, %r0 /* disable interrupts */ + mtsp %r1,%sr3 /* and store it in sr3 */ + mfctl %cr30,%r1 xor %r1,%r30,%r30 /* ye olde xor trick */ xor %r1,%r30,%r1 @@ -147,6 +153,7 @@ linux_gateway_entry: */ mtsp %r0,%sr7 /* get kernel space into sr7 */ + ssm PSW_SM_I, %r0 /* enable interrupts */ STREGM %r1,FRAME_SIZE(%r30) /* save r1 (usp) here for now */ mfctl %cr30,%r1 /* get task ptr in %r1 */ LDREG TI_TASK(%r1),%r1 |