From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fhigh-b5-smtp.messagingengine.com (fhigh-b5-smtp.messagingengine.com [202.12.124.156]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D9F2A4CE681; Tue, 15 Sep 2026 20:43:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.12.124.156 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789504999; cv=none; b=LdOTphCUTUuSuDbjnwCH+x5YcphHpCU+sg7LIq2e6c46FH5OgB5Kr76MMPxHRiExbH0/WSjgMFmXPTLXvrw5RvAQdec+BVuZ2PUmvVFa9k9dlTJhexw09HH+vjxX37LnnxGGz887H0G8jrRqn4YstxswvVxQLOJTC/G9rbnwrDA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789504999; c=relaxed/simple; bh=0vIflhtXXxOwOBEDRe71mQNwlgm5iE/KJItxt8teBsE=; h=MIME-Version:Date:From:To:Cc:Message-Id:In-Reply-To:References: Subject:Content-Type; b=u5pkwN216rXtSzmFkwr4gbn589dSD+TZAIhz9YdWnBtwxzgmDB0VwHs7WN31z6Nm77WqgvluAV8fnFCvLAJhZs6Q36zqrPhCVr+o5wJBbpWLZHiWbfw20tGzwqFlFhRU8YyUD8qUGr3Zhm6ifkvPDM0PrsQ37vWLPgIdOfqh12o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arndb.de; spf=pass smtp.mailfrom=arndb.de; dkim=pass (2048-bit key) header.d=arndb.de header.i=@arndb.de header.b=eC43FpzQ; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=mFTfdROm; arc=none smtp.client-ip=202.12.124.156 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arndb.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arndb.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=arndb.de header.i=@arndb.de header.b="eC43FpzQ"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="mFTfdROm" Received: from ams-compute-02.internal (ams-compute-02.internal [10.64.2.62]) by mailfhigh.stl.internal (Postfix) with ESMTP id B34087A0157; Tue, 15 Sep 2026 16:43:13 -0400 (EDT) Received: from ams-imap-03 ([10.64.2.23]) by ams-compute-02.internal (MEProxy); Tue, 15 Sep 2026 16:43:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arndb.de; h=cc :cc:content-transfer-encoding:content-type:content-type:date :date:from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to; s=fm3; t=1789504992; x=1789591392; bh=15pOBlFMsh5jfKoNMrL//3KNxWvcFV8EfGKeQla5sKY=; b= eC43FpzQI3LRK7U5lutYM/Ets47K++Iotu0sPzAGHMZ0XkaYHvZMdYSAsqWuj8YM pS1R3AHUZCdfZROFvkJYYodJkaUspravVBFrIpjnSmJnemrbNdfnuOLO31kyPV/j qwaH6tHxiDxn2arKPZWMeNkIrTATNXyq3mMpO3/VQjBaOlBo1XAQRDJCOu2Y2Fju c3NEFfLw7xHa71qlbJagKAOqroS3Brp04tssU+C7+tagGOQPr3XAqvYVUWpvBWpZ 07bD8yLa40Aa3TGrlw00tHxQhlq2rawDAkH2YzCab88RJn5ANKvZagb1zNk2V55A FXgVveCHm++mZVyNmOm5aQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:content-type:date:date:feedback-id:feedback-id :from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm1; t=1789504992; x= 1789591392; bh=15pOBlFMsh5jfKoNMrL//3KNxWvcFV8EfGKeQla5sKY=; b=m FTfdROmnjRy9O0gkMPdWKSto4yG0z/zWGj1xhW3iBzORXg6+Qtw/Aah98yRHpM6M dGiwSm97Mjas8WylnP3JwnoV2SJ1rOyyWVqJUIBkrLvhXTXtcZckSaY2PsJlN4xz Ci6XM6J+i2QhLeJ094pgUebybULluTIkG0MhYFS42XHdrMCSslc/wPO2rqOZsx2P XWu4eRjHjmASZNklEgEUqZ/lr/WGkGb7J26xKfaE9Jt8gjDUlQVSJkP0qv0+JF2m IBEIOfP/rr2/6NkX0EQxBMJcu8CyXt2aHJUFUJlrfUY9u248WUL8ZrZ6Mb/gwcvX EIDwOH362F/89RqSw3W2Q== X-ME-Sender: X-ME-Proxy-Cause: dmFkZTFxMghYPF+YRfPPYYPknJQjcOeaaG4ChTx7OF/GTfAYXJumfELWaQ15UOtE3kfYWX cIqMqfXou/29BjJi0QYlY8BSoFAC8C3IaaWm2k5SFlzaEKb6BFCNfrZsEMX/6xPjYRIkVo +cSQrDFEVqhjIy41EMuR3Oz+CdEOytfazJHWjbwS9Lh2vvwfE56Xv4zmeCy95DhOeNu6Vw 33WWzcasVwmRS0e1edFWMe+sSOVZQeGSxcrHdLKVRk+MQb/pkVlSCb2NWEOZtLD7mindfG jDQLMsaNC6yKsX2CO4LhzGT8leLk7jvTkKaVgpq2tb6UeqMQulMYTgNMALz1QKs8EAhII+ G124qdDtSxYVnZ1oKNMa2/Pgdh2CWaPLegLLLigIdgAd2WJLn0HvemwQD2rJoor9s8HpZW BMlPLTeOyxuHHk9Rk4yPh/69lKdsBXehZqg2cqnwLNG56gYuutUNilLDwH9IAB1PnDvZ29 BMavl7wuqWq6SIgV8oNvtncJBTdrg0JdsiGXW0huKuhyPCCkPs8bvh32ucltPwYWMhvl0V RmiKl86883a9/HOGgTBITMq6gxgAKiS5wEpxOYjUE3ZGWMCvW61DqWTEVxiQTN8kSc4uxN hjIUybdKGYU+M5cW0LQ6LtVOVBQyyLvzmi1HhSH1GD/PuVonS0e8hOJtR1Fw X-ME-Proxy: Feedback-ID: i56a14606:Fastmail Received: by mailuser.ams.internal (Postfix, from userid 501) id 2BEB732A0081; Tue, 15 Sep 2026 16:43:10 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ThreadId: AJz9fPW9cgrZ Date: Tue, 15 Sep 2026 22:42:49 +0200 From: "Arnd Bergmann" To: "Paul Moore" , "Arnd Bergmann" Cc: "Stephen Smalley" , =?UTF-8?Q?Ondrej_Mosn=C3=A1=C4=8Dek?= , selinux@vger.kernel.org, linux-kernel@vger.kernel.org Message-Id: <5a285431-9b60-4d87-87c4-a5b52021ea65@app.fastmail.com> In-Reply-To: References: <20260915195728.3519469-1-arnd@kernel.org> Subject: Re: [PATCH] selinux: use explicit 64-bit division Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On Tue, Sep 15, 2026, at 22:36, Paul Moore wrote: > On Tue, Sep 15, 2026 at 3:57=E2=80=AFPM Arnd Bergmann wrote: >> >> From: Arnd Bergmann >> >> On 32-bit targets, the division of a 64-bit integer by 33 causes a >> function call: >> >> arm-linux-gnueabi-ld: security/selinux/selinuxfs.o: in function `sel_= read_class': >> selinuxfs.c:(.text+0xdcc): undefined reference to `__aeabi_uldivmod' >> arm-linux-gnueabi-ld: security/selinux/selinuxfs.o: in function `sel_= read_perm': >> selinuxfs.c:(.text+0xed0): undefined reference to `__aeabi_uldivmod' >> >> Replace this with an explicit call to div_u64() and div_u64_rem() to >> annotate that these are potentially very slow. >> >> Fixes: fc68b6a45f16 ("selinux: convert selinuxfs inode numbers from u= nsigned long to u64") >> Signed-off-by: Arnd Bergmann >> --- >> security/selinux/selinuxfs.c | 8 ++++++-- >> 1 file changed, 6 insertions(+), 2 deletions(-) > > Thanks Arnd. > > As sashiko pointed out[1], since we don't really use the full 64-bit > inode space, what do you think about the following fix instead? Ah right, I hadn't checked the actual value of SEL_INO_MASK, and the description of your patch made it sound like the 64-bit space was actually required. Your patch is better then, you can treat my mail as Reported-by. Arnd