diff options
| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2024-12-23 20:07:29 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-01-02 10:30:53 +0100 |
| commit | 53e049204d291826c76a6eaff521dee65fdc9534 (patch) | |
| tree | 0076435b793bbbe1fd486af9ce67e5f6a719e2ad | |
| parent | 45883477b19e7bc90b72265e413d46fab895f2ae (diff) | |
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>
| -rw-r--r-- | mm/vmalloc.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index a0b650f50faa..7c6694514606 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2709,7 +2709,8 @@ static void __vunmap(const void *addr, int deallocate_pages) struct page *page = area->pages[i]; BUG_ON(!page); - mod_memcg_page_state(page, MEMCG_VMALLOC, -1); + if (!(area->flags & VM_MAP_PUT_PAGES)) + mod_memcg_page_state(page, MEMCG_VMALLOC, -1); /* * High-order allocs for huge vmallocs are split, so * can be freed as an array of order-0 allocations @@ -2717,7 +2718,8 @@ static void __vunmap(const void *addr, int deallocate_pages) __free_pages(page, 0); cond_resched(); } - 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); } |