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| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2024-12-23 20:18:00 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-02-01 18:22:30 +0100 |
| commit | 461091c27f55bda99d05d30f7dc920302bf8b7a1 (patch) | |
| tree | 7e3328124dac87f807d0e08a0ecf1cf66e4ebddc /mm | |
| parent | e8d3c53c6f1cccea9c03113f06dd39521c228831 (diff) | |
| download | linux-461091c27f55bda99d05d30f7dc920302bf8b7a1.tar.gz linux-461091c27f55bda99d05d30f7dc920302bf8b7a1.tar.bz2 linux-461091c27f55bda99d05d30f7dc920302bf8b7a1.zip | |
vmalloc: fix accounting with i915
[ Upstream commit a2e740e216f5bf49ccb83b6d490c72a340558a43 ]
If the caller of vmap() specifies VM_MAP_PUT_PAGES (currently only the
i915 driver), we will decrement nr_vmalloc_pages and MEMCG_VMALLOC in
vfree(). These counters are incremented by vmalloc() but not by vmap() so
this will cause an underflow. Check the VM_MAP_PUT_PAGES flag before
decrementing either counter.
Link: https://lkml.kernel.org/r/20241211202538.168311-1-willy@infradead.org
Fixes: b944afc9d64d ("mm: add a VM_MAP_PUT_PAGES flag for vmap")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Balbir Singh <balbirs@nvidia.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/vmalloc.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index d6a4794fa8ca..fd1c8f51aa53 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2269,7 +2269,8 @@ static void __vunmap(const void *addr, int deallocate_pages) BUG_ON(!page); __free_pages(page, 0); } - atomic_long_sub(area->nr_pages, &nr_vmalloc_pages); + if (!(area->flags & VM_MAP_PUT_PAGES)) + atomic_long_sub(area->nr_pages, &nr_vmalloc_pages); kvfree(area->pages); } |