• Linus Torvalds's avatar
    Merge branch 'tlb-fixes' · 706a1ea6
    Linus Torvalds authored
    Merge fixes for missing TLB shootdowns.
    
    This fixes a couple of cases that involved us possibly freeing page
    table structures before the required TLB shootdown had been done.
    
    There are a few cleanup patches to make the code easier to follow, and
    to avoid some of the more problematic cases entirely when not necessary.
    
    To make this easier for backports, it undoes the recent lazy TLB
    patches, because the cleanups and fixes are more important, and Rik is
    ok with re-doing them later when things have calmed down.
    
    The missing TLB flush was only delayed, and the wrong ordering only
    happened under memory pressure (and in theory under a couple of other
    fairly theoretical situations), so this may have been all very unlikely
    to have hit people in practice.
    
    But getting the TLB shootdown wrong is _so_ hard to debug and see that I
    consider this a crticial fix.
    
    Many thanks to Jann Horn for having debugged this.
    
    * tlb-fixes:
      x86/mm: Only use tlb_remove_table() for paravirt
      mm: mmu_notifier fix for tlb_end_vma
      mm/tlb, x86/mm: Support invalidating TLB caches for RCU_TABLE_FREE
      mm/tlb: Remove tlb_remove_table() non-concurrent condition
      mm: move tlb_table_flush to tlb_flush_mmu_free
      x86/mm/tlb: Revert the recent lazy TLB patches
    706a1ea6
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