Messages in this thread Patch in this message | | | Date | Mon, 22 Nov 2004 03:17:09 -0800 | From | William Lee Irwin III <> | Subject | [bugfix] fix do_wp_page_mk_pte_writable() in 2.6.10-rc2-mm3 |
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On Sun, Nov 21, 2004 at 10:39:29PM -0800, Andrew Morton wrote: > 4level-core-patch.patch > 4level core patch
vma->vm_ops->page_mkwrite() is supposed to be able to sleep, but this function doesn't unmap the pte across the call and worse yet, reuses the pte across a drop and reacquisition of ->page_table_lock.
Index: mm3-2.6.10-rc2/mm/memory.c =================================================================== --- mm3-2.6.10-rc2.orig/mm/memory.c 2004-11-22 02:54:12.815541779 -0800 +++ mm3-2.6.10-rc2/mm/memory.c 2004-11-22 02:57:22.095766811 -0800 @@ -1268,6 +1268,7 @@ static inline int do_wp_page_mk_pte_writable(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, + pmd_t *pmd, pte_t *page_table, struct page *old_page, pte_t pte) @@ -1279,6 +1280,7 @@ if (vma->vm_ops && vma->vm_ops->page_mkwrite) { /* Notify the page owner without the lock held so they can * sleep if they want to */ + pte_unmap(page_table); spin_unlock(&mm->page_table_lock); if (vma->vm_ops->page_mkwrite(vma, old_page) < 0) @@ -1291,6 +1293,7 @@ * return, as we can count on the MMU to tell us if they didn't * also make it writable */ + page_table = pte_offset_map(pmd, address); if (!pte_same(*page_table, pte)) goto minor_fault; } @@ -1352,7 +1355,7 @@ unlock_page(old_page); if (reuse) /* We can just make the PTE writable */ - return do_wp_page_mk_pte_writable(mm, vma, address, + return do_wp_page_mk_pte_writable(mm, vma, address, pmd, page_table, old_page, pte); } - 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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