From: Naoya Horiguchi Date: Wed, 11 Feb 2015 23:28:06 +0000 (-0800) Subject: mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP) X-Git-Tag: fixes-v4.0-rc1~131^2~12 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=48684a65b4e;p=pandora-kernel.git mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP) walk_page_range() silently skips vma having VM_PFNMAP set, which leads to undesirable behaviour at client end (who called walk_page_range). For example for pagemap_read(), when no callbacks are called against VM_PFNMAP vma, pagemap_read() may prepare pagemap data for next virtual address range at wrong index. That could confuse and/or break userspace applications. This patch avoid this misbehavior caused by vma(VM_PFNMAP) like follows: - for pagemap_read() which has its own ->pte_hole(), call the ->pte_hole() over vma(VM_PFNMAP), - for clear_refs and queue_pages which have their own ->tests_walk, just return 1 and skip vma(VM_PFNMAP). This is no problem because these are not interested in hole regions, - for other callers, just skip the vma(VM_PFNMAP) as a default behavior. Signed-off-by: Naoya Horiguchi Signed-off-by: Shiraz Hashim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed