diff options
| author | David Gibson <david@gibson.dropbear.id.au> | 2007-10-28 22:20:34 +0100 |
|---|---|---|
| committer | Adrian Bunk <bunk@kernel.org> | 2007-10-28 22:20:34 +0100 |
| commit | 6a93b22bc8569315b2e0ce07297b73673882925a (patch) | |
| tree | cfa0678e8456c404f5107730c9520f5622fdca2f | |
| parent | 42ea9d4b9da1bb26d519f91c9464fd093c7a56a2 (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.c | 4 |
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); |