From mboxrd@z Thu Jan 1 00:00:00 1970 From: Suren Baghdasaryan Subject: [PATCH 11/40] mm: prevent slabobj_ext allocations for slabobj_ext and kmem_cache objects Date: Mon, 1 May 2023 09:54:21 -0700 Message-ID: <20230501165450.15352-12-surenb@google.com> References: <20230501165450.15352-1-surenb@google.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1682960133; x=1685552133; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=AxHF9zQp9trScXtaAl0tt4NG3XQrBAxJQ/ayq1tkXak=; b=tJm7WR8AdSF6O5qWHaKU1D/ysKeRzFc3FiZT54ezTvTsHezyhXNB2hdIvEgmyHbI2P coE7FK11G2KLLdp82iDrBRtaK1XJdqiYBBu7Bzgc0CjbScOB1xMrdceY1iUR8li4Lunu QxqPry7kkIxD8xjnoCiSp2i1c6RgrlFShVMk73jBCUlai0Pj6tzx2wQKCiGt42ycRlUY Q6iiOWoraxytw320styP6cKZ8CPR54fhZHUXwBTe18PxhhkTB2K2EgrVvGyA9dqorw8v 3z+UXLp0f4HuyIt3egDvW6I8g1tJRbXw06CphA32uVzlUNPHB3VM7B/5KkyjlKHh6bO/ vApw== In-Reply-To: <20230501165450.15352-1-surenb@google.com> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: akpm@linux-foundation.org Cc: kent.overstreet@linux.dev, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, roman.gushchin@linux.dev, mgorman@suse.de, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, corbet@lwn.net, void@manifault.com, peterz@infradead.org, juri.lelli@redhat.com, ldufour@linux.ibm.com, catalin.marinas@arm.com, will@kernel.org, arnd@arndb.de, tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, x86@kernel.org, peterx@redhat.com, david@redhat.com, axboe@kernel.dk, mcgrof@kernel.org, masahiroy@kernel.org, nathan@kernel.org, dennis@kernel.org, tj@kernel.org, muchun.song@linux.dev, rppt@kernel.org, paulmck@kernel.org, pasha.tatashin@soleen.com, yosryahmed@google.com, yuzhao@google.com, dhowells@redhat.com, hughd@google.com, andreyknvl@gmail.com, keescook@chromium.org Use __GFP_NO_OBJ_EXT to prevent recursions when allocating slabobj_ext objects. Also prevent slabobj_ext allocations for kmem_cache objects. Signed-off-by: Suren Baghdasaryan --- mm/slab.h | 6 ++++++ mm/slab_common.c | 2 ++ 2 files changed, 8 insertions(+) diff --git a/mm/slab.h b/mm/slab.h index 25d14b3a7280..b1c22dc87047 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -450,6 +450,12 @@ prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p) if (!need_slab_obj_ext()) return NULL; + if (s->flags & SLAB_NO_OBJ_EXT) + return NULL; + + if (flags & __GFP_NO_OBJ_EXT) + return NULL; + slab = virt_to_slab(p); if (!slab_obj_exts(slab) && WARN(alloc_slab_obj_exts(slab, s, flags, false), diff --git a/mm/slab_common.c b/mm/slab_common.c index f11cc072b01e..42777d66d0e3 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -220,6 +220,8 @@ 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) -- 2.40.1.495.gc816e09b53d-goog