s390: TASK_SIZE for kernel threads

Return a sensible value if TASK_SIZE if called from a kernel thread.

This gets us around an issue with copy_mount_options that does a magic
size calculation "TASK_SIZE - (unsigned long)data" while in a kernel
thread and data pointing to kernel space.

Cc: <stable@vger.kernel.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2017-02-24 07:43:51 +01:00
Родитель 2793784307
Коммит fb94a687d9
1 изменённых файлов: 2 добавлений и 1 удалений

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@ -91,7 +91,8 @@ extern void execve_tail(void);
* User space process size: 2GB for 31 bit, 4TB or 8PT for 64 bit.
*/
#define TASK_SIZE_OF(tsk) ((tsk)->mm->context.asce_limit)
#define TASK_SIZE_OF(tsk) ((tsk)->mm ? \
(tsk)->mm->context.asce_limit : TASK_MAX_SIZE)
#define TASK_UNMAPPED_BASE (test_thread_flag(TIF_31BIT) ? \
(1UL << 30) : (1UL << 41))
#define TASK_SIZE TASK_SIZE_OF(current)