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Tue, 11 Jul 2023 13:46:35 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id iPqDAztdrWTSYwAAMHmgww (envelope-from ); Tue, 11 Jul 2023 13:46:35 +0000 From: Vlastimil Babka To: Christoph Lameter , David Rientjes , Pekka Enberg , Joonsoo Kim Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>, Roman Gushchin , linux-mm@kvack.org, patches@lists.linux.dev, linux-kernel@vger.kernel.org, Matteo Rizzo , Jann Horn , Andrey Konovalov , Marco Elver , Alexander Potapenko , kasan-dev@googlegroups.com, Kees Cook , linux-hardening@vger.kernel.org, Vlastimil Babka Subject: [PATCH 2/2] mm/slub: remove freelist_dereference() Date: Tue, 11 Jul 2023 15:46:25 +0200 Message-ID: <20230711134623.12695-4-vbabka@suse.cz> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230711134623.12695-3-vbabka@suse.cz> References: <20230711134623.12695-3-vbabka@suse.cz> MIME-Version: 1.0 X-Rspamd-Queue-Id: E0BD1C0025 X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: wir9s8yf1ayioittor76kip36qp1wxty X-HE-Tag: 1689083196-268556 X-HE-Meta: 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 FbHgFwfm 0ooChBtb8Hxaf1pGe1A2P2uoytHHXs3wrfeXWGUS6lVlS6EDqWmWHWCsKYXgmIuR0lxtkWwM+vbjG5W6V6mvNtqppqn3JfIlmgXGll11NIoD67KVxI4b35G4/whZQ5OOfBLJAWYclX3eXshLWGb34GFsncgdQC2NhUd9YPxSi+OUUPkSDkj02FLD2144EEGgt4dG0a7x5IODLyrnpKML5HTRMB6l9awSLH5CUiP/TXEHjhICoOw+A4KQTFXSHDPKHE7eVlshAfCJeXMSva2PxPfI9UXg/HsGfyjaNwYnK7CasgjrNd4aq+I6eYw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: freelist_dereference() is a one-liner only used from get_freepointer(). Remove it and make get_freepointer() call freelist_ptr_decode() directly to make the code easier to follow. Signed-off-by: Vlastimil Babka Acked-by: Kees Cook --- mm/slub.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 07edad305512..c4556a5dab4b 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -397,18 +397,14 @@ static inline void *freelist_ptr_decode(const struct kmem_cache *s, return decoded; } -/* Returns the freelist pointer recorded at location ptr_addr. */ -static inline void *freelist_dereference(const struct kmem_cache *s, - void *ptr_addr) -{ - return freelist_ptr_decode(s, *(freeptr_t *)(ptr_addr), - (unsigned long)ptr_addr); -} - static inline void *get_freepointer(struct kmem_cache *s, void *object) { - object = kasan_reset_tag(object); - return freelist_dereference(s, (freeptr_t *)(object + s->offset)); + unsigned long ptr_addr; + freeptr_t p; + + ptr_addr = ((unsigned long)kasan_reset_tag(object)) + s->offset; + p = *(freeptr_t *)(ptr_addr); + return freelist_ptr_decode(s, p, ptr_addr); } #ifndef CONFIG_SLUB_TINY