From: Martin Schwidefsky <schwidefsky@de.ibm.com>
Correct check for user space faults. If the failing address space is in the
secondary address space and uaccess has been switched to KERNEL_DS with
set_fs, check_user_space() erroneously returns 1.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/arch/s390/mm/fault.c | 9 +++++----
1 files changed, 5 insertions(+), 4 deletions(-)
diff -puN arch/s390/mm/fault.c~s390-kernel-faults arch/s390/mm/fault.c
--- 25/arch/s390/mm/fault.c~s390-kernel-faults Thu Mar 24 15:28:52 2005
+++ 25-akpm/arch/s390/mm/fault.c Thu Mar 24 15:28:52 2005
@@ -87,6 +87,7 @@ static int __check_access_register(struc
if (areg == 0)
/* Access via access register 0 -> kernel address */
return 0;
+ save_access_regs(current->thread.acrs);
if (regs && areg < NUM_ACRS && current->thread.acrs[areg] <= 1)
/*
* access register contains 0 -> kernel address,
@@ -115,11 +116,11 @@ static inline int check_user_space(struc
* 3: Home Segment Table Descriptor
*/
int descriptor = S390_lowcore.trans_exc_code & 3;
- if (descriptor == 1) {
- save_access_regs(current->thread.acrs);
+ if (unlikely(descriptor == 1))
return __check_access_register(regs, error_code);
- }
- return descriptor >> 1;
+ if (descriptor == 2)
+ return current->thread.mm_segment.ar4;
+ return descriptor != 0;
}
/*
_