kernel-fxtec-pro1x/arch/s390/include/asm/mmu.h
Martin Schwidefsky 050eef364a [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>
2010-08-24 09:26:34 +02:00

23 lines
691 B
C

#ifndef __MMU_H
#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;
unsigned long asce_bits;
unsigned long asce_limit;
unsigned long vdso_base;
int noexec;
int has_pgste; /* The mmu context has extended page tables */
int alloc_pgste; /* cloned contexts will have extended page tables */
} mm_context_t;
#define INIT_MM_CONTEXT(name) \
.context.list_lock = __SPIN_LOCK_UNLOCKED(name.context.list_lock), \
.context.crst_list = LIST_HEAD_INIT(name.context.crst_list), \
.context.pgtable_list = LIST_HEAD_INIT(name.context.pgtable_list),
#endif