[PATCH v5 07/37] mm: introduce __GFP_NO_OBJ_EXT flag to selectively prevent slabobj_ext creation
From: Suren Baghdasaryan <surenb@google.com>
Date: 2024-03-06 18:25:00
Also in:
cgroups, linux-arch, linux-doc, linux-fsdevel, linux-iommu, linux-mm, lkml
Subsystem:
memory management, memory management - core, slab allocator, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Vlastimil Babka, Harry Yoo, Linus Torvalds
Introduce __GFP_NO_OBJ_EXT flag in order to prevent recursive allocations when allocating slabobj_ext on a slab. Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Kees Cook <redacted> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Vlastimil Babka <redacted> --- include/linux/gfp_types.h | 11 +++++++++++ mm/slub.c | 2 ++ 2 files changed, 13 insertions(+)
diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h
index 868c8fb1bbc1..e36e168d8cfd 100644
--- a/include/linux/gfp_types.h
+++ b/include/linux/gfp_types.h@@ -52,6 +52,9 @@ enum { #endif #ifdef CONFIG_LOCKDEP ___GFP_NOLOCKDEP_BIT, +#endif +#ifdef CONFIG_SLAB_OBJ_EXT + ___GFP_NO_OBJ_EXT_BIT, #endif ___GFP_LAST_BIT };
@@ -93,6 +96,11 @@ enum { #else #define ___GFP_NOLOCKDEP 0 #endif +#ifdef CONFIG_SLAB_OBJ_EXT +#define ___GFP_NO_OBJ_EXT BIT(___GFP_NO_OBJ_EXT_BIT) +#else +#define ___GFP_NO_OBJ_EXT 0 +#endif /* * Physical address zone modifiers (see linux/mmzone.h - low four bits)
@@ -133,12 +141,15 @@ enum { * node with no fallbacks or placement policy enforcements. * * %__GFP_ACCOUNT causes the allocation to be accounted to kmemcg. + * + * %__GFP_NO_OBJ_EXT causes slab allocation to have no object extension. */ #define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE) #define __GFP_WRITE ((__force gfp_t)___GFP_WRITE) #define __GFP_HARDWALL ((__force gfp_t)___GFP_HARDWALL) #define __GFP_THISNODE ((__force gfp_t)___GFP_THISNODE) #define __GFP_ACCOUNT ((__force gfp_t)___GFP_ACCOUNT) +#define __GFP_NO_OBJ_EXT ((__force gfp_t)___GFP_NO_OBJ_EXT) /** * DOC: Watermark modifiers
diff --git a/mm/slub.c b/mm/slub.c
index 6ab9f8f38ac5..2ba5d7b2711d 100644
--- a/mm/slub.c
+++ b/mm/slub.c@@ -1899,6 +1899,8 @@ static int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, void *vec; gfp &= ~OBJCGS_CLEAR_MASK; + /* Prevent recursive extension vector allocation */ + gfp |= __GFP_NO_OBJ_EXT; vec = kcalloc_node(objects, sizeof(struct slabobj_ext), gfp, slab_nid(slab)); if (!vec)
--
2.44.0.278.ge034bb2e1d-goog