Messages in this thread | | | Date | Tue, 6 Mar 2012 13:37:00 +1100 | From | David Gibson <> | Subject | Re: [PATCH 2/2] hugepages: Fix use after free bug in "quota" handling |
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On Thu, Feb 16, 2012 at 08:33:51PM +0800, Hillf Danton wrote: > On Thu, Feb 16, 2012 at 12:24 PM, David Gibson > <david@gibson.dropbear.id.au> wrote: > > @@ -1046,12 +1124,12 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma, > > if (!page) { > > page = alloc_buddy_huge_page(h, NUMA_NO_NODE); > > if (!page) { > > - hugetlb_put_quota(inode->i_mapping, chg); > > + hugepage_subpool_put_pages(spool, chg); > > return ERR_PTR(-VM_FAULT_SIGBUS); > > } > > } > > > > - set_page_private(page, (unsigned long) mapping); > > + set_page_private(page, (unsigned long)spool);
Sorry for the very delayed reply. Somehow I never spotted this when it first came. I think I must have acidentally deleted it when cleaning out automated messages and spam.
> Page mapping is used in unmap_ref_private(), and I am > wondering it no longer works:-(
Good point. But unmap_ref_private() does take the vma, so it should be able to get to the mapping from there. I'll respin doing that, instead of using page_private().
> > @@ -2392,7 +2471,8 @@ retry_avoidcopy: > > > > /* Drop page_table_lock as buddy allocator may be called */ > > spin_unlock(&mm->page_table_lock); > > - new_page = alloc_huge_page(vma, address, outside_reserve); > > + new_page = alloc_huge_page(vma, address, outside_reserve, > > + subpool_vma(vma)); > > Change in the number of parameters of alloc_huge_page() > looks unnecessary.
Because alloc_huge_page() also takes vma. Yeah, fair enough. I'll change that in the respin too.
-- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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