The patch titled
Subject: mm: WARN_ON_ONCE if f_op->mmap() change vma's start address
has been added to the -mm tree. Its filename is
mm-warn_on_once-if-f_op-mmap-change-vmas-start-address.patch
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From: Joonsoo Kim <js1304@xxxxxxxxx>
Subject: mm: WARN_ON_ONCE if f_op->mmap() change vma's start address
During reviewing the source code, I found a comment which mention that
after f_op->mmap(), vma's start address can be changed. I didn't verify
that it is really possible, because there are so many f_op->mmap()
implementation. But if there are some mmap() which change vma's start
address, it is possible error situation, because we already prepare prev
vma, rb_link and rb_parent and these are related to original address.
So add WARN_ON_ONCE for finding that this situtation really happens.
Signed-off-by: Joonsoo Kim <js1304@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 4 ++++
1 file changed, 4 insertions(+)
diff -puN mm/mmap.c~mm-warn_on_once-if-f_op-mmap-change-vmas-start-address mm/mmap.c
--- a/mm/mmap.c~mm-warn_on_once-if-f_op-mmap-change-vmas-start-address
+++ a/mm/mmap.c
@@ -1488,7 +1488,11 @@ munmap_back:
*
* Answer: Yes, several device drivers can do it in their
* f_op->mmap method. -DaveM
+ * Bug: If addr is changed, prev, rb_link, rb_parent should
+ * be updated for vma_link()
*/
+ WARN_ON_ONCE(addr != vma->vm_start);
+
addr = vma->vm_start;
pgoff = vma->vm_pgoff;
vm_flags = vma->vm_flags;
_
Patches currently in -mm which might be from js1304@xxxxxxxxx are
linux-next.patch
mm-highmem-use-pkmap_nr-to-calculate-an-index-of-pkmap.patch
mm-highmem-remove-useless-pool_lock.patch
mm-highmem-remove-page_address_pool-list.patch
mm-highmem-remove-page_address_pool-list-v2.patch
mm-highmem-makes-flush_all_zero_pkmaps-return-index-of-last-flushed-entry.patch
mm-highmem-makes-flush_all_zero_pkmaps-return-index-of-last-flushed-entry-v2.patch
mm-highmem-get-virtual-address-of-the-page-using-pkmap_addr.patch
memcg-make-it-possible-to-use-the-stock-for-more-than-one-page.patch
memcg-reclaim-when-more-than-one-page-needed.patch
memcg-change-defines-to-an-enum.patch
memcg-kmem-accounting-basic-infrastructure.patch
mm-add-a-__gfp_kmemcg-flag.patch
memcg-kmem-controller-infrastructure.patch
mm-allocate-kernel-pages-to-the-right-memcg.patch
res_counter-return-amount-of-charges-after-res_counter_uncharge.patch
memcg-kmem-accounting-lifecycle-management.patch
memcg-use-static-branches-when-code-not-in-use.patch
memcg-allow-a-memcg-with-kmem-charges-to-be-destructed.patch
memcg-execute-the-whole-memcg-freeing-in-free_worker.patch
fork-protect-architectures-where-thread_size-=-page_size-against-fork-bombs.patch
memcg-add-documentation-about-the-kmem-controller.patch
slab-slub-struct-memcg_params.patch
slab-annotate-on-slab-caches-nodelist-locks.patch
slab-slub-consider-a-memcg-parameter-in-kmem_create_cache.patch
memcg-allocate-memory-for-memcg-caches-whenever-a-new-memcg-appears.patch
memcg-infrastructure-to-match-an-allocation-to-the-right-cache.patch
memcg-skip-memcg-kmem-allocations-in-specified-code-regions.patch
slb-always-get-the-cache-from-its-page-in-kmem_cache_free.patch
slb-allocate-objects-from-memcg-cache.patch
memcg-destroy-memcg-caches.patch
memcg-slb-track-all-the-memcg-children-of-a-kmem_cache.patch
memcg-slb-shrink-dead-caches.patch
memcg-aggregate-memcg-cache-values-in-slabinfo.patch
slab-propagate-tunable-values.patch
slub-slub-specific-propagation-changes.patch
slub-slub-specific-propagation-changes-fix.patch
kmem-add-slab-specific-documentation-about-the-kmem-controller.patch
bootmem-remove-not-implemented-function-call-bootmem_arch_preferred_node.patch
avr32-kconfig-remove-have_arch_bootmem.patch
bootmem-remove-alloc_arch_preferred_bootmem.patch
bootmem-fix-wrong-call-parameter-for-free_bootmem.patch
bootmem-fix-wrong-call-parameter-for-free_bootmem-fix.patch
mm-warn_on_once-if-f_op-mmap-change-vmas-start-address.patch
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