From: Martin Schwidefsky 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 Signed-off-by: Andrew Morton --- 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; } /* _