From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Tue, 28 Oct 2025 10:42:56 +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 1vDgEC-00Cdtt-1U for lore@lore.pengutronix.de; Tue, 28 Oct 2025 10:42:56 +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 1vDgEB-0005oe-SI for lore@pengutronix.de; Tue, 28 Oct 2025 10:42:56 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=U2v9MF053OeMDOztz7wHl2TCS1u720Kc5WpxU0lSwUg=; b=ooyTO3xIzYwx/IIEPMPWd7l6W4 JcZSNVbtp6VZWGgvnos5mk5VQd+oh7m2oC/kweg1KWYQ+82+aNbNRh6OyFPc8NDh0d1l9wXlepy3K L6NMBHfQ4BI6MNqsLIonNPhkg06pHObibcqsZpJ2BoOsKciqlNsOavLjgiZiG72kBfLzMG6MZfkJg zQtQSru3C/EhKXVMCN+enRXuIl1UQWJ6Tm2+t6vCffXJHEdd8zuGX1bhVJMsiZ3rWHloXYeUYSR9f yVnzTeL2vQsOsujH5WagFWv7BZNm8uDugcmF/h+gkC3Lu7TWidYPxiQjvNBpZGICzxFeHF97LBADB wU06psPQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vDgDc-0000000Ferb-0Bzi; Tue, 28 Oct 2025 09:42:20 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vDgDZ-0000000FerB-2whG for barebox@lists.infradead.org; Tue, 28 Oct 2025 09:42:19 +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 1vDgDX-0005gU-RV; Tue, 28 Oct 2025 10:42:15 +0100 Received: from pty.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::c5]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1vDgDX-005qvM-2A; Tue, 28 Oct 2025 10:42:15 +0100 Received: from sha by pty.whiteo.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1vDgDX-005141-1s; Tue, 28 Oct 2025 10:42:15 +0100 Date: Tue, 28 Oct 2025 10:42:15 +0100 From: Sascha Hauer To: Ahmad Fatoum Cc: barebox@lists.infradead.org Message-ID: References: <20251027075438.2480311-1-a.fatoum@barebox.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251027075438.2480311-1-a.fatoum@barebox.org> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251028_024217_743183_0B1A4F86 X-CRM114-Status: GOOD ( 19.42 ) 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: , 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=-4.1 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH RFC 1/3] lib: add talloc for overlaying a tree onto allocations 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) On Mon, Oct 27, 2025 at 08:54:32AM +0100, Ahmad Fatoum wrote: > +#ifndef __TALLOC_H__ > +#define __TALLOC_H__ > + > +#include > + > +struct talloc { > + struct talloc *child; > + struct talloc *next; > + union { > + struct talloc *prev; > + struct talloc *parent; /* Valid only when is_first(mem) */ > + }; > +}; Currently tlsf allocations are 8 byte aligned. On 32bit architectures struct talloc will be 12 bytes, so talloc allocations will only have 4 byte alignment. > +static void *talloc_ctx_init(struct talloc *hdr, const void *parent) > +{ > + void *mem; > + > + if (!hdr) > + return NULL; > + > + memset(hdr, 0, sizeof(*hdr)); > + > + mem = hdr2mem(hdr); > + talloc_steal(parent, mem); > + return mem; > +} > + > +/** > + * talloc_usable_size() - Report the size of the talloation s/talloation/tallocation/ > + * > + * @mem: pointer to previously talloc'ed memory chunk. > + * > + * Return: size of tallocation > + */ > +size_t talloc_usable_size(void *mem) > +{ > + return malloc_usable_size(mem) - sizeof(struct talloc); > +} > +EXPORT_SYMBOL(talloc_usable_size); This function is unused. Do we need it? > +/** > + * talloc_free() - Deallocate a talloc'ed memory chunk and all the chunks depending on it. > + * > + * @mem: pointer to previously talloc'ed memory chunk. > + */ > +void talloc_free(void *mem) > +{ > + struct talloc *hdr = mem2hdr(mem); > + > + if (ZERO_OR_NULL_PTR(hdr)) > + return; For correctness I believe you have to check mem here, not hdr. (Although the above works as long as sizeof(struct talloc) <= ZERO_SIZE_PTR) Sascha -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |