From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 86133C021A0 for ; Wed, 12 Feb 2025 17:42:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:References :In-Reply-To:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=C8p6DqcWVDZkl2upGoqr8pn0vDUxdXkIuXEz98RzcT0=; b=3956bC/8t/tnye OejX7w3qM7WVsxTNl7SZ9G+7205HikiyZ3z/ER7thlw3AK4haCTirzP2BOuyIbA+gOiBVM3h8cD6S A2OZZubXVLGTcTFlokvLUJU7/JoJVj7yRHjWkm9qMRgENqfGsaLYskWYbVlhRQ5qqrpGON3fwcO5m 9Fr8qO1vUPJ9iwchMfcyvKeqUPpsdjVCq7IegecD39Kx9VqKilrgsC8wnxj6NMiJ6M2yz8ptVYXSv LEOOrtoUpXjiw/duzaA/iKSenpqu0KedtJqQsQ1LoSF/QZRGOU+49PNCIYw3Bq1MibTd/Zo3wCPm7 HUrfGf6CRV1bogRrg9BA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tiGkd-00000008MAF-0M8j; Wed, 12 Feb 2025 17:42:19 +0000 Received: from smtp-out1.suse.de ([195.135.223.130]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tfEI9-0000000HWnG-1HEG for linux-riscv@lists.infradead.org; Tue, 04 Feb 2025 08:28:22 +0000 Received: from hawking.nue2.suse.org (unknown [IPv6:2a07:de40:a101:3:92b1:1cff:fe69:ddc]) by smtp-out1.suse.de (Postfix) with ESMTP id AB8C021102; Tue, 4 Feb 2025 08:28:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1738657699; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ueZJENhFmqxCDCfMr0f5hMTIbOvm/X56I5HrFFhEOPQ=; b=dFv7EHfmYh3C3Jea8QMhoMa9cE2WwgDaJWHdZx7304SlbraygrFKWmEP/YY9Qix3hUnL5O UlcH/m6AX4AR2gcxBKuSySQc4ZY8iZ2muni7cYaSeVi+BpxFusNlq70PMcDcIHngGuFNfS iHtUt8QrdHPxmFPKW5EqVPc6isz1eN0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1738657699; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ueZJENhFmqxCDCfMr0f5hMTIbOvm/X56I5HrFFhEOPQ=; b=cDFUmSHWzMp1a5BZmIvBbVG7eAHrS4yWLyk7hogKeROH5sp5sh/oV3DMVnIR44M6lIoTsi aPK8e2iZG/bAQYAQ== Authentication-Results: smtp-out1.suse.de; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=dFv7EHfm; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=cDFUmSHW DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1738657699; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ueZJENhFmqxCDCfMr0f5hMTIbOvm/X56I5HrFFhEOPQ=; b=dFv7EHfmYh3C3Jea8QMhoMa9cE2WwgDaJWHdZx7304SlbraygrFKWmEP/YY9Qix3hUnL5O UlcH/m6AX4AR2gcxBKuSySQc4ZY8iZ2muni7cYaSeVi+BpxFusNlq70PMcDcIHngGuFNfS iHtUt8QrdHPxmFPKW5EqVPc6isz1eN0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1738657699; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ueZJENhFmqxCDCfMr0f5hMTIbOvm/X56I5HrFFhEOPQ=; b=cDFUmSHWzMp1a5BZmIvBbVG7eAHrS4yWLyk7hogKeROH5sp5sh/oV3DMVnIR44M6lIoTsi aPK8e2iZG/bAQYAQ== Received: by hawking.nue2.suse.org (Postfix, from userid 17005) id 927364A0517; Tue, 4 Feb 2025 09:28:19 +0100 (CET) From: Andreas Schwab To: Jessica Clarke Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] riscv/futex: sign extend compare value in atomic cmpxchg In-Reply-To: (Jessica Clarke's message of "Mon, 3 Feb 2025 21:25:00 +0000") References: Date: Tue, 04 Feb 2025 09:28:19 +0100 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 X-Spamd-Result: default: False [14.38 / 50.00]; SPAM_FLAG(5.00)[]; NEURAL_SPAM_LONG(3.50)[1.000]; BAYES_HAM(-3.00)[100.00%]; HFILTER_HOSTNAME_UNKNOWN(2.50)[]; NEURAL_SPAM_SHORT(2.09)[0.696]; RDNS_NONE(2.00)[]; ONCE_RECEIVED(1.20)[]; HFILTER_HELO_IP_A(1.00)[hawking.nue2.suse.org]; HFILTER_HELO_NORES_A_OR_MX(0.30)[hawking.nue2.suse.org]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; MIME_GOOD(-0.10)[text/plain]; RCVD_NO_TLS_LAST(0.10)[]; MX_GOOD(-0.01)[]; FROM_EQ_ENVFROM(0.00)[]; DIRECT_TO_MX(0.00)[Gnus/5.13 (Gnus v5.13)]; ARC_NA(0.00)[]; FROM_HAS_DN(0.00)[]; MIME_TRACE(0.00)[0:+]; FUZZY_BLOCKED(0.00)[rspamd.com]; RCPT_COUNT_THREE(0.00)[3]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DKIM_TRACE(0.00)[suse.de:+]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; RCVD_COUNT_ONE(0.00)[1]; TO_DN_SOME(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:dkim,suse.de:mid,suse.de:email] X-Rspamd-Queue-Id: AB8C021102 X-Rspamd-Action: add header X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Spamd-Bar: ++++++++++++++ X-Spam: Yes X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250204_002821_489501_0EAE7546 X-CRM114-Status: UNSURE ( 7.48 ) X-CRM114-Notice: Please train this message. X-Mailman-Approved-At: Wed, 12 Feb 2025 09:27:38 -0800 X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Feb 03 2025, Jessica Clarke wrote: > On 3 Feb 2025, at 10:06, Andreas Schwab wrote: >> >> Make sure the compare value in the lr/sc loop is sign extended to match >> what lr.w does. Fortunately, due to the compiler keeping the register >> contents sign extended anyway the lack of the explicit extension didn't >> result in wrong code so far, but this cannot be relied upon. > > GCC may guarantee this today, It doesn't, that's the point! -- Andreas Schwab, SUSE Labs, schwab@suse.de GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7 "And now for something completely different." _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv