From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Tue, 14 Nov 2023 09:17:54 +0100 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1r2ocM-00B5w8-0q for lore@lore.pengutronix.de; Tue, 14 Nov 2023 09:17:54 +0100 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1r2ocM-0001Z5-AB for lore@pengutronix.de; Tue, 14 Nov 2023 09:17:54 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: Content-Transfer-Encoding:MIME-Version:Message-Id:Date:Subject:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=Lwq1WZLQZhxXip/JSUukVNhf+prsEpfqnAIjtUP6/zw=; b=sG/a9S0/1wDWg+ ImJKVJ5NbxkRP2or7v1ZwPiUN8NLHUrP0CcPklW+5FttqyNGyY+LiWHRtm65PS61QWPZZE+YmfDAL ZPi5rlo73grcVt237wR4GlbvuaOwR+zfTJg9jz9s4dEOVk/Dw6WSG/VFgtzkgnG6zYlMMYMLDl0uW jRrnS91b3LY1DFG8zUjLaFze+nRBjnVsh+4va/VJE0cuyWCy6zjOJTnxgZp8D9wIXVzT/2h4qd6MG YyJEGuYWKLZXvuZJSi4SPWNmt8yiEkeJxUY6lZLCLJ2HEmoGD8UZppqzd/AZ8+9r74EbNk3YoYeC5 P/qKWMCGVEjNrFpKCWHg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r2oak-00FN37-1C; Tue, 14 Nov 2023 08:16:14 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1r2oaf-00FN2M-2t for barebox@lists.infradead.org; Tue, 14 Nov 2023 08:16:12 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1r2oaY-0001OL-5J; Tue, 14 Nov 2023 09:16:02 +0100 Received: from [2a0a:edc0:0:1101:1d::28] (helo=dude02.red.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1r2oaX-008wvi-PC; Tue, 14 Nov 2023 09:16:01 +0100 Received: from sha by dude02.red.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1r2oaX-003dhI-2K; Tue, 14 Nov 2023 09:16:01 +0100 From: Sascha Hauer To: Barebox List Date: Tue, 14 Nov 2023 09:16:00 +0100 Message-Id: <20231114081600.867531-1-s.hauer@pengutronix.de> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231114_001609_968775_A5DAE624 X-CRM114-Status: GOOD ( 11.82 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: afa@pengutronix.de Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-4.9 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE, T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH] dlmalloc: hide out of bounds accesses from compiler X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) Once we add __alloc_size attributes to allocations, GCC will complain about violation of memory safety in dlmalloc.c. dlmalloc uses this macro to convert a pointer returned by malloc() to its own data structures: #define mem2chunk(mem) ((mchunkptr)((char*)(mem) - 2*SIZE_SZ)) As dlmalloc internally uses malloc itself and uses mem2chunk afterwards on this pointer gcc rightfully complains about illegal accesses. Silence these warnings by converting mem2chunk to a static inline function. I would have expected that we need a OPTIMIZER_HIDE_VAR() in mem2chunk(), but that doesn't seem to be necessary right now. Maybe it will in later gcc versions. Signed-off-by: Sascha Hauer --- common/dlmalloc.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/common/dlmalloc.c b/common/dlmalloc.c index 16ea3cafb6..d420e8bd9d 100644 --- a/common/dlmalloc.c +++ b/common/dlmalloc.c @@ -628,7 +628,11 @@ nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /* conversion from malloc headers to user pointers, and back */ #define chunk2mem(p) ((void*)((char*)(p) + 2*SIZE_SZ)) -#define mem2chunk(mem) ((mchunkptr)((char*)(mem) - 2*SIZE_SZ)) + +static inline mchunkptr mem2chunk(void *mem) +{ + return mem - 2 * SIZE_SZ; +} /* pad request bytes into a usable size */ @@ -1683,8 +1687,8 @@ void *memalign(size_t alignment, size_t bytes) this is always possible. */ - brk = (char*) mem2chunk(((unsigned long) (m + alignment - 1)) & - -((signed) alignment)); + brk = (char*) mem2chunk((void *)(((unsigned long) (m + alignment - 1)) & + -((signed) alignment))); if ((long)(brk - (char*)(p)) < MINSIZE) brk = brk + alignment; -- 2.39.2