From 050eef364ad700590a605a0749f825cab4834b1e Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 24 Aug 2010 09:26:21 +0200 Subject: [S390] fix tlb flushing vs. concurrent /proc accesses The tlb flushing code uses the mm_users field of the mm_struct to decide if each page table entry needs to be flushed individually with IPTE or if a global flush for the mm_struct is sufficient after all page table updates have been done. The comment for mm_users says "How many users with user space?" but the /proc code increases mm_users after it found the process structure by pid without creating a new user process. Which makes mm_users useless for the decision between the two tlb flusing methods. The current code can be confused to not flush tlb entries by a concurrent access to /proc files if e.g. a fork is in progres. The solution for this problem is to make the tlb flushing logic independent from the mm_users field. Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/mmu.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/s390/include/asm/mmu.h') diff --git a/arch/s390/include/asm/mmu.h b/arch/s390/include/asm/mmu.h index 99e3409102b9..78522cdefdd4 100644 --- a/arch/s390/include/asm/mmu.h +++ b/arch/s390/include/asm/mmu.h @@ -2,6 +2,8 @@ #define __MMU_H typedef struct { + atomic_t attach_count; + unsigned int flush_mm; spinlock_t list_lock; struct list_head crst_list; struct list_head pgtable_list; -- cgit v1.2.3-59-g8ed1b