From nobody Mon May 25 00:10:14 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 E62743ACF14; Wed, 20 May 2026 08:28:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779265701; cv=none; b=mqYdCZSYdfLVX71xK15xliWjkfQUNpIcg1/BUIEZoFiOrTmgfUndTEGfbR6RD9tx0wbu28DbGP+r8zl69+Z5LdOfwDbDayBWXmkusp2CBoHd+NnY4SzRALZ5oHG2/kkgUBzo6uSNF13NvzWGOqAUMHsSjTuq+g+yQfMFknJCsuc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779265701; c=relaxed/simple; bh=8Q5QyemmTUMjbiINWr69WfXntSAsST0nWimvUhXQUYM=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=cj66p8eKMkhpf8/yXc8uJmz06GUs0gxDXZC1V/DM9meVmR4q6P+sqCw8ZOmrKrfd2anyqC6bhel1UBvQ92RyVJ+3rpD5UPsjgkMPiLtoflryEZl9QozB4gT+kxOSJLD8b1p68Rt8TzBFNmjP4jlstkz9SJTaPogM3EFtSBy9vIs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=Hy7EaORv; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=66wmyhly; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Hy7EaORv"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="66wmyhly" Date: Wed, 20 May 2026 08:28:07 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1779265689; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dhZwxOPjBFo/Y/qPot9l1e0ZQneC/2lViVOUoQXrT5g=; b=Hy7EaORv9mycDhZ7zRZ2pCjVG0gfKxvcm6rRWq5BFG7tZN9cMXRjXgWPQw+iVVMUxEb1Ci zOPTO2pQO1pko2XiULYdGvk3oec7629NoR0jJ3BUf1Fj+nNVSQ++5TUkis21Y9DjB7kewQ wndOb6FbYqxfzx48iQvlnZZ55Suu3jx76daHS5aGOGfloHorjz+EDH8nSv1T8xuxXTVbko skwSRxYtg1ALcUzcTMR1p/Vl96CmwDsXTqrH1AXgDc3JQ4CzM3Hu4ukOQSycgkfkHnCW8g ZZbegPlo3RVx4uGF8xXe/sMe8yltyiXtE+Uy+GM5+cnaF/OB5IgBpNOCab+XsA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1779265689; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dhZwxOPjBFo/Y/qPot9l1e0ZQneC/2lViVOUoQXrT5g=; b=66wmyhly4iBEHfP8fpuc5NHbPIQr8m/XzWWcONOOx6RCCcuwvUyRCe3Ueul5Rcox7gGtLf j0WLf9iNd4ixobCQ== From: "tip-bot2 for Heiko Carstens" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: locking/core] seqlock: Allow UBSAN_ALIGNMENT to fail optimizing Cc: Arnd Bergmann , Heiko Carstens , "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20260519110315.1385307-1-hca@linux.ibm.com> References: <20260519110315.1385307-1-hca@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <177926568726.711.8535042934240313341.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the locking/core branch of tip: Commit-ID: 43a037d4fa6d7e7f9437e069f857a5e06eb2dff7 Gitweb: https://git.kernel.org/tip/43a037d4fa6d7e7f9437e069f857a5e06= eb2dff7 Author: Heiko Carstens AuthorDate: Tue, 19 May 2026 13:03:15 +02:00 Committer: Peter Zijlstra CommitterDate: Tue, 19 May 2026 13:49:01 +02:00 seqlock: Allow UBSAN_ALIGNMENT to fail optimizing With gcc-15 and gcc-16 with UBSAN_ALIGNMENT enabled the compiler fails to inline and optimize __scoped_seqlock_bug() away on s390: s390x-16.1.0-ld: kernel/sched/build_policy.o: in function `__scoped_seqlock= _next': /.../seqlock.h:1286:(.text+0x22030): undefined reference to `__scoped_seqlo= ck_bug' Fix this by adding UBSAN_ALIGNMENT to the list of config options where a not inlined empty __scoped_seqlock_bug() is allowed. Closes: https://lore.kernel.org/r/20260515092057.810542-1-arnd@kernel.org/ Reported-by: Arnd Bergmann Signed-off-by: Heiko Carstens Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20260519110315.1385307-1-hca@linux.ibm.com --- include/linux/seqlock.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index 5a40252..f865491 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -1259,14 +1259,15 @@ static __always_inline void __scoped_seqlock_cleanu= p(struct ss_tmp *sst) =20 extern void __scoped_seqlock_invalid_target(void); =20 -#if (defined(CONFIG_CC_IS_GCC) && CONFIG_GCC_VERSION < 90000) || defined(C= ONFIG_KASAN) +#if (defined(CONFIG_CC_IS_GCC) && CONFIG_GCC_VERSION < 90000) || \ + defined(CONFIG_KASAN) || defined(CONFIG_UBSAN_ALIGNMENT) /* * For some reason some GCC-8 architectures (nios2, alpha) have trouble * determining that the ss_done state is impossible in __scoped_seqlock_ne= xt() * below. * - * Similarly KASAN is known to confuse compilers enough to break this. But= we - * don't care about code quality for KASAN builds anyway. + * Similarly KASAN and UBSAN_ALIGNMENT are known to confuse compilers enou= gh + * to break this. But we don't care about code quality for such builds any= way. */ static inline void __scoped_seqlock_bug(void) { } #else