| Message ID | 20160129123544.GB146512@black.fi.intel.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Fri, Jan 29, 2016 at 1:35 PM, Kirill A. Shutemov <kirill.shutemov@linux.intel.com> wrote: > From 691a961bb401c5815ed741dac63591efbc6027e3 Mon Sep 17 00:00:00 2001 > From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > Date: Fri, 29 Jan 2016 15:06:17 +0300 > Subject: [PATCH 2/2] mempolicy: do not try to queue pages from > !vma_migratable() > > Maybe I miss some point, but I don't see a reason why we try to queue > pages from non migratable VMAs. > > The only case when we can queue pages from such VMA is MPOL_MF_STRICT > plus MPOL_MF_MOVE or MPOL_MF_MOVE_ALL for VMA which has pages on LRU, > but gfp mask is not sutable for migaration (see mapping_gfp_mask() check > in vma_migratable()). That's looks like a bug to me. > > Let's filter out non-migratable vma at start of queue_pages_test_walk() > and go to queue_pages_pte_range() only if MPOL_MF_MOVE or > MPOL_MF_MOVE_ALL flag is set. I've run the fuzzer with these two patches for the weekend and seen no crashes. I guess we can consider this as fixed. Thanks! > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > --- > mm/mempolicy.c | 14 +++++--------- > 1 file changed, 5 insertions(+), 9 deletions(-) > > diff --git a/mm/mempolicy.c b/mm/mempolicy.c > index 27d135408a22..4c4187c0e1de 100644 > --- a/mm/mempolicy.c > +++ b/mm/mempolicy.c > @@ -548,8 +548,7 @@ retry: > goto retry; > } > > - if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) > - migrate_page_add(page, qp->pagelist, flags); > + migrate_page_add(page, qp->pagelist, flags); > } > pte_unmap_unlock(pte - 1, ptl); > cond_resched(); > @@ -625,7 +624,7 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end, > unsigned long endvma = vma->vm_end; > unsigned long flags = qp->flags; > > - if (vma->vm_flags & VM_PFNMAP) > + if (!vma_migratable(vma)) > return 1; > > if (endvma > end) > @@ -644,16 +643,13 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end, > > if (flags & MPOL_MF_LAZY) { > /* Similar to task_numa_work, skip inaccessible VMAs */ > - if (vma_migratable(vma) && > - vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)) > + if (vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)) > change_prot_numa(vma, start, endvma); > return 1; > } > > - if ((flags & MPOL_MF_STRICT) || > - ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) && > - vma_migratable(vma))) > - /* queue pages from current vma */ > + /* queue pages from current vma */ > + if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) > return 0; > return 1; > } > -- > 2.7.0.rc3 > > -- > You received this message because you are subscribed to the Google Groups "syzkaller" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller+unsubscribe@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 27d135408a22..4c4187c0e1de 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -548,8 +548,7 @@ retry: goto retry; } - if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) - migrate_page_add(page, qp->pagelist, flags); + migrate_page_add(page, qp->pagelist, flags); } pte_unmap_unlock(pte - 1, ptl); cond_resched(); @@ -625,7 +624,7 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end, unsigned long endvma = vma->vm_end; unsigned long flags = qp->flags; - if (vma->vm_flags & VM_PFNMAP) + if (!vma_migratable(vma)) return 1; if (endvma > end) @@ -644,16 +643,13 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end, if (flags & MPOL_MF_LAZY) { /* Similar to task_numa_work, skip inaccessible VMAs */ - if (vma_migratable(vma) && - vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)) + if (vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)) change_prot_numa(vma, start, endvma); return 1; } - if ((flags & MPOL_MF_STRICT) || - ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) && - vma_migratable(vma))) - /* queue pages from current vma */ + /* queue pages from current vma */ + if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) return 0; return 1; }