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| author | Liam Howlett <liam.howlett@oracle.com> | 2022-10-18 21:17:12 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-10-21 06:27:23 +0200 |
| commit | a57b70519d1f7c53be98478623652738e5ac70d5 (patch) | |
| tree | 625e504bf350f9a976ed21978855ca851cb349ff /mm/hugetlb.c | |
| parent | mm/mmap.c: __vma_adjust(): suppress uninitialized var warning (diff) | |
| download | linux-a57b70519d1f7c53be98478623652738e5ac70d5.tar.xz linux-a57b70519d1f7c53be98478623652738e5ac70d5.zip | |
mm/mmap: fix MAP_FIXED address return on VMA merge
mmap should return the start address of newly mapped area when successful.
On a successful merge of a VMA, the return address was changed and thus
was violating that expectation from userspace.
This is a restoration of functionality provided by 309d08d9b3a3
(mm/mmap.c: fix mmap return value when vma is merged after call_mmap()).
For completeness of fixing MAP_FIXED, implement the comments from the
previous discussion to never update the address and fail if the address
changes. Leaving the error as a WARN_ON() to avoid crashing the kernel.
Link: https://lkml.kernel.org/r/20221018191613.4133459-1-Liam.Howlett@oracle.com
Link: https://lore.kernel.org/all/Y06yk66SKxlrwwfb@lakrids/
Link: https://lore.kernel.org/all/20201203085350.22624-1-liuzixian4@huawei.com/
Fixes: 4dd1b84140c1 ("mm/mmap: use advanced maple tree API for mmap_region()")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Cc: Liu Zixian <liuzixian4@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/hugetlb.c')
0 files changed, 0 insertions, 0 deletions