• Heiko Carstens's avatar
    s390/mm: fix flush_tlb_kernel_range() · f6a70a07
    Heiko Carstens authored
    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.
    
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
    Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
    f6a70a07
tlbflush.h 3.25 KB