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authorSuren Baghdasaryan <surenb@google.com>2024-03-21 09:36:29 -0700
committerAndrew Morton <akpm@linux-foundation.org>2024-04-25 20:55:51 -0700
commit768c33be1b3166791bd554abd105154719eba43d (patch)
treeed312c4d1be53d846a88be6f26010ab78d9d7893
parent21c690a349baab895dc68ab70d291e1598d7109d (diff)
mm: introduce __GFP_NO_OBJ_EXT flag to selectively prevent slabobj_ext creation
Introduce __GFP_NO_OBJ_EXT flag in order to prevent recursive allocations when allocating slabobj_ext on a slab. Link: https://lkml.kernel.org/r/20240321163705.3067592-8-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andreas Hindborg <a.hindborg@samsung.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Gary Guo <gary@garyguo.net> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--include/linux/gfp_types.h11
-rw-r--r--mm/slub.c2
2 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h
index 13becafe41df..313be4ad79fd 100644
--- a/include/linux/gfp_types.h
+++ b/include/linux/gfp_types.h
@@ -55,6 +55,9 @@ enum {
#ifdef CONFIG_LOCKDEP
___GFP_NOLOCKDEP_BIT,
#endif
+#ifdef CONFIG_SLAB_OBJ_EXT
+ ___GFP_NO_OBJ_EXT_BIT,
+#endif
___GFP_LAST_BIT
};
@@ -95,6 +98,11 @@ 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)
@@ -135,12 +143,15 @@ 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 5c896c76812d..2cb53642a091 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1889,6 +1889,8 @@ 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)