Commit badb8bb9 authored May 10, 2011 by Martin Schwidefsky Committed by Martin Schwidefsky May 10, 2011

[S390] fix alloc_pgste check in init_new_context



Processes started with kernel_execve from a kernel thread will have
current->mm==NULL. Reading current->mm->context.alloc_pgste will
read a more or less random bit from lowcore in this case. If the
bit turns out to be set the whole process tree started this way
will allocate page table extensions although they have no need
for it.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

parent 3d8dcb3c

arch/s390/include/asm/mmu_context.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -23,7 +23,7 @@ static inline int init_new_context(struct task_struct *tsk,
		#ifdef CONFIG_64BIT
		mm->context.asce_bits \|= _ASCE_TYPE_REGION3;
		#endif
		if (current->mm->context.alloc_pgste) {
		if (current->mm && current->mm->context.alloc_pgste) {
		/*
		* alloc_pgste indicates, that any NEW context will be created
		* with extended page tables. The old context is unchanged. The