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authorMax Filippov <jcmvbkbc@gmail.com>2013-05-15 19:02:06 +0400
committerChris Zankel <chris@zankel.net>2013-06-05 10:14:19 -0700
commit87962c4db7f594c377d8b0b5a5f563e5f0b5d5d0 (patch)
treeede110ec898b37350d60af1e66c4b0b7ddbe7ce8 /arch/xtensa
parent51fc41a90603eaee7b6d03b6027be8f22fcf8ef9 (diff)
downloadlinux-87962c4db7f594c377d8b0b5a5f563e5f0b5d5d0.tar.gz
xtensa: flush TLB entries for pages of non-current mm correctly
Sometimes under high memory pressure one process gets a page of another process, which manifests itself with an invalid instruction exception. This happens because flush_tlb_page fails to clear TLB entries when called with vma that does not belong to current mm, because it does not set RASID appropriately. When page reclaiming mechanism swaps physical pages out replacing their PTEs with none or swap PTEs, it calls flush_tlb_page. Later physical page may be reused elsewhere, but the stale TLB mapping still refers to it, allowing process that owned the mapping to see the new state of that physical page. Put ASID of the mm that owns vma to the RASID to fix that issue. Also replace otherwise meaningless local_save_flags with local_irq_save. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net>
Diffstat (limited to 'arch/xtensa')
-rw-r--r--arch/xtensa/mm/tlb.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/xtensa/mm/tlb.c b/arch/xtensa/mm/tlb.c
index 5411aa67c68..743346150ee 100644
--- a/arch/xtensa/mm/tlb.c
+++ b/arch/xtensa/mm/tlb.c
@@ -64,7 +64,7 @@ void flush_tlb_mm(struct mm_struct *mm)
{
if (mm == current->active_mm) {
unsigned long flags;
- local_save_flags(flags);
+ local_irq_save(flags);
__get_new_mmu_context(mm);
__load_mmu_context(mm);
local_irq_restore(flags);
@@ -94,7 +94,7 @@ void flush_tlb_range (struct vm_area_struct *vma,
printk("[tlbrange<%02lx,%08lx,%08lx>]\n",
(unsigned long)mm->context, start, end);
#endif
- local_save_flags(flags);
+ local_irq_save(flags);
if (end-start + (PAGE_SIZE-1) <= _TLB_ENTRIES << PAGE_SHIFT) {
int oldpid = get_rasid_register();
@@ -128,9 +128,10 @@ void flush_tlb_page (struct vm_area_struct *vma, unsigned long page)
if(mm->context == NO_CONTEXT)
return;
- local_save_flags(flags);
+ local_irq_save(flags);
oldpid = get_rasid_register();
+ set_rasid_register(ASID_INSERT(mm->context));
if (vma->vm_flags & VM_EXEC)
invalidate_itlb_mapping(page);