From: Heiko Carstens Date: Mon, 4 Mar 2013 13:14:11 +0000 (+0100) Subject: s390/mm: fix flush_tlb_kernel_range() X-Git-Tag: v3.8.4~30 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=38130595db91b30c5ff7965e393b3754077703f2;p=karo-tx-linux.git s390/mm: fix flush_tlb_kernel_range() commit f6a70a07079518280022286a1dceb797d12e1edf upstream. Our flush_tlb_kernel_range() implementation calls __tlb_flush_mm() with &init_mm as argument. __tlb_flush_mm() however will only flush tlbs for the passed in mm if its mm_cpumask is not empty. For the init_mm however its mm_cpumask has never any bits set. Which in turn means that our flush_tlb_kernel_range() implementation doesn't work at all. This can be easily verified with a vmalloc/vfree loop which allocates a page, writes to it and then frees the page again. A crash will follow almost instantly. To fix this remove the cpumask_empty() check in __tlb_flush_mm() since there shouldn't be too many mms with a zero mm_cpumask, besides the init_mm of course. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/s390/include/asm/tlbflush.h b/arch/s390/include/asm/tlbflush.h index 1d8fe2b17ef6..6b32af30878c 100644 --- a/arch/s390/include/asm/tlbflush.h +++ b/arch/s390/include/asm/tlbflush.h @@ -74,8 +74,6 @@ static inline void __tlb_flush_idte(unsigned long asce) static inline void __tlb_flush_mm(struct mm_struct * mm) { - if (unlikely(cpumask_empty(mm_cpumask(mm)))) - return; /* * If the machine has IDTE we prefer to do a per mm flush * on all cpus instead of doing a local flush if the mm