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authorDavid Gibson <david@gibson.dropbear.id.au>2007-10-28 22:20:34 +0100
committerAdrian Bunk <bunk@kernel.org>2007-10-28 22:20:34 +0100
commit6a93b22bc8569315b2e0ce07297b73673882925a (patch)
treecfa0678e8456c404f5107730c9520f5622fdca2f
parent42ea9d4b9da1bb26d519f91c9464fd093c7a56a2 (diff)
hugetlb: check for brk() entering a hugepage region
Unlike mmap(), the codepath for brk() creates a vma without first checking that it doesn't touch a region exclusively reserved for hugepages. On powerpc, this can allow it to create a normal page vma in a hugepage region, causing oopses and other badness. Add a test to prevent this. With this patch, brk() will simply fail if it attempts to move the break into a hugepage reserved region. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Adrian Bunk <bunk@kernel.org>
-rw-r--r--mm/mmap.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index f2ac461a357e..a04576de3254 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1870,6 +1870,10 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
if ((addr + len) > TASK_SIZE || (addr + len) < addr)
return -EINVAL;
+ error = is_hugepage_only_range(current->mm, addr, len);
+ if (error)
+ return error;
+
flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
error = arch_mmap_check(addr, len, flags);