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author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2010-08-24 09:26:21 +0200 |
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committer | Martin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com> | 2010-08-24 09:26:34 +0200 |
commit | 050eef364ad700590a605a0749f825cab4834b1e (patch) | |
tree | 2714c9cf7edcbf394971cc2c929e5ab2ea34d6a6 /arch/s390/include/asm/mmu.h | |
parent | [S390] s390: fix build error (sys_execve) (diff) | |
download | linux-050eef364ad700590a605a0749f825cab4834b1e.tar.xz linux-050eef364ad700590a605a0749f825cab4834b1e.zip |
[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 <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include/asm/mmu.h')
-rw-r--r-- | arch/s390/include/asm/mmu.h | 2 |
1 files changed, 2 insertions, 0 deletions
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; |