diff options
| author | Li Zhong <zhong@linux.vnet.ibm.com> | 2014-08-06 16:07:56 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-09-17 09:21:54 -0700 |
| commit | da574914df05176343a1f610c9edf30cd70dec0e (patch) | |
| tree | 87c10c61493f37d432de577eb1eb19e0272d9cfd /mm | |
| parent | b39ff9dfd3ba34f08f4cfa8aaf1872aa2d0099d6 (diff) | |
mm: fix potential infinite loop in dissolve_free_huge_pages()
commit d0177639310d23c7739500df3c6ce6fdfe34acec upstream.
It is possible for some platforms, such as powerpc to set HPAGE_SHIFT to
0 to indicate huge pages not supported.
When this is the case, hugetlbfs could be disabled during boot time:
hugetlbfs: disabling because there are no supported hugepage sizes
Then in dissolve_free_huge_pages(), order is kept maximum (64 for
64bits), and the for loop below won't end: for (pfn = start_pfn; pfn <
end_pfn; pfn += 1 << order)
As suggested by Naoya, below fix checks hugepages_supported() before
calling dissolve_free_huge_pages().
[rientjes@google.com: no legitimate reason to call dissolve_free_huge_pages() when !hugepages_supported()]
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/hugetlb.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 7a0a73d2fcff..7ae54449f252 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1089,6 +1089,9 @@ void dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) unsigned long pfn; struct hstate *h; + if (!hugepages_supported()) + return; + /* Set scan step to minimum hugepage size */ for_each_hstate(h) if (order > huge_page_order(h)) |