From: Benjamin LaHaise This patch fixes a fairly serious tlb flushing bug that makes aio use under uml very unreliable -- SEGVs, Oops and panic()s occur as a result of stale tlb entires being used by uml when aio switches mms due to the fact that uml does not implement the activate_mm() hook. This patch introduces a simple but correct approach (read: hammer) for implementing activate_mm() in uml by doing a force_flush_all() if the new mm is different from old. With this patch in place, uml is able to succeed at the aio test case that was randomly faulting for me before. Cc: Jeff Dike Cc: Signed-off-by: Andrew Morton --- include/asm-um/mmu_context.h | 4 ++++ 1 files changed, 4 insertions(+) diff -puN include/asm-um/mmu_context.h~uml-tlb-flushing-fix include/asm-um/mmu_context.h --- 25/include/asm-um/mmu_context.h~uml-tlb-flushing-fix Mon Jul 11 15:01:15 2005 +++ 25-akpm/include/asm-um/mmu_context.h Mon Jul 11 15:01:15 2005 @@ -16,8 +16,12 @@ #define deactivate_mm(tsk,mm) do { } while (0) +extern void force_flush_all(void); + static inline void activate_mm(struct mm_struct *old, struct mm_struct *new) { + if (old != new) + force_flush_all(); } static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, _