The patch titled Subject: vmalloc: fix accounting with i915 has been added to the -mm mm-hotfixes-unstable branch. Its filename is vmalloc-fix-accounting-with-i915.patch
This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...
This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------ From: "Matthew Wilcox (Oracle)" willy@infradead.org Subject: vmalloc: fix accounting with i915 Date: Wed, 11 Dec 2024 20:25:37 +0000
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 Cc: Christoph Hellwig hch@lst.de Cc: Michal Hocko mhocko@kernel.org 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 ---
mm/vmalloc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/mm/vmalloc.c~vmalloc-fix-accounting-with-i915 +++ a/mm/vmalloc.c @@ -3374,7 +3374,8 @@ void vfree(const void *addr) struct page *page = vm->pages[i];
BUG_ON(!page); - mod_memcg_page_state(page, MEMCG_VMALLOC, -1); + if (!(vm->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 @@ -3382,7 +3383,8 @@ void vfree(const void *addr) __free_page(page); cond_resched(); } - atomic_long_sub(vm->nr_pages, &nr_vmalloc_pages); + if (!(vm->flags & VM_MAP_PUT_PAGES)) + atomic_long_sub(vm->nr_pages, &nr_vmalloc_pages); kvfree(vm->pages); kfree(vm); } _
Patches currently in -mm which might be from willy@infradead.org are
vmalloc-fix-accounting-with-i915.patch mm-page_alloc-cache-page_zone-result-in-free_unref_page.patch mm-make-alloc_pages_mpol-static.patch mm-page_alloc-export-free_frozen_pages-instead-of-free_unref_page.patch mm-page_alloc-move-set_page_refcounted-to-callers-of-post_alloc_hook.patch mm-page_alloc-move-set_page_refcounted-to-callers-of-prep_new_page.patch mm-page_alloc-move-set_page_refcounted-to-callers-of-get_page_from_freelist.patch mm-page_alloc-move-set_page_refcounted-to-callers-of-__alloc_pages_cpuset_fallback.patch mm-page_alloc-move-set_page_refcounted-to-callers-of-__alloc_pages_may_oom.patch mm-page_alloc-move-set_page_refcounted-to-callers-of-__alloc_pages_direct_compact.patch mm-page_alloc-move-set_page_refcounted-to-callers-of-__alloc_pages_direct_reclaim.patch mm-page_alloc-move-set_page_refcounted-to-callers-of-__alloc_pages_slowpath.patch mm-page_alloc-move-set_page_refcounted-to-end-of-__alloc_pages.patch mm-page_alloc-add-__alloc_frozen_pages.patch mm-mempolicy-add-alloc_frozen_pages.patch slab-allocate-frozen-pages.patch