| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.10 12/75] s390: TASK_SIZE for kernel threads | Date | Mon, 13 Mar 2017 16:43:21 +0800 |
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4.10-stable review patch. If anyone has any objections, please let me know.
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From: Martin Schwidefsky <schwidefsky@de.ibm.com>
commit fb94a687d96c570d46332a4a890f1dcb7310e643 upstream.
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.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/s390/include/asm/processor.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -89,7 +89,8 @@ 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)
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