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author | 2015-02-11 15:28:06 -0800 | |
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committer | 2015-02-11 17:06:06 -0800 | |
commit | 48684a65b4e3ff544d62532c1b78962c9677b632 (patch) | |
tree | 884da0dc303b41042c9928b40ef7ae651d34e22d /tools/perf/scripts/python/call-graph-from-postgresql.py | |
parent | mempolicy: apply page table walker on queue_pages_range() (diff) | |
download | wireguard-linux-48684a65b4e3ff544d62532c1b78962c9677b632.tar.xz wireguard-linux-48684a65b4e3ff544d62532c1b78962c9677b632.zip |
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 <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Shiraz Hashim <shashim@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'tools/perf/scripts/python/call-graph-from-postgresql.py')
0 files changed, 0 insertions, 0 deletions