From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 E55BB347B4; Mon, 16 Dec 2024 09:32:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734341540; cv=none; b=XWpksws1fbkrgNzvVRI7q0sefdAfjutXN/5DveId610xADAi0g4yTrZDzoj4An0gb3rytj3BfejnLlXx0SJDNwYTqVpUVNgaF6inYqJcLFLHisLoj64QwTzv7H6XocXfzgYP5EcJTn+G6PHyjTxCUuDSP8FEOc85NoqEz8/U1Kc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734341540; c=relaxed/simple; bh=eHDuhJrDWtNoQCCRmpWOIBKF9ykyUy/44poicFT/LXc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=m/MG4AXjdq/JSRXSrfNZ+BpAaV+a2RkmEJNuDxCRrFIVvTszybQu1DN7ClxdjTP2B6d1MvtPXABQh6U94xY/JalvdLmqIqDXZO52pyGk9OW60l9nDyTtENASLNWKqtUyQ8Jm7oUvzd8C93wlwAJSORSQVW3CVQA2pIQj73OhflY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=bmD8o+gm; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="bmD8o+gm" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=wiPCFq4dyWxF7N4NTpB9RFuzOSDApJ/3JrMLkOH2sr8=; b=bmD8o+gmWCbOSBYlB6WtQp4UWo 1npSSqhWJepe6bfloesgdRn8NkbFagRiEcu90hPuuC8LvN+8lYnjGvwgPgr7z5bRVrcIIX3p8NouY zQF56QscRFtlpNFsvS1TWtsHzfAcehJJRo1h3ecZvOFr0pHdITqka842AWcGq0K2CvWFxEcbPEFX2 hKC7NCAy6+01br1h2sgTir8WPAqxgVc+IpN3hWGcgQwSriWB7iQmXMk0KnEQ0uAUrFsrZbtcMQVW5 d3beOVgNwSod7XsKSp7OTeipuvrbJibRyFaKc+ZTuVU+voN3PcXURf03wmmhi49ELmEuFv2SCAuHl Wgf01HvA==; Received: from 77-249-17-89.cable.dynamic.v4.ziggo.nl ([77.249.17.89] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tN7Sa-0000000F7p6-3pxz; Mon, 16 Dec 2024 09:32:17 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id E898730031E; Mon, 16 Dec 2024 10:32:15 +0100 (CET) Date: Mon, 16 Dec 2024 10:32:15 +0100 From: Peter Zijlstra To: linux-kernel@vger.kernel.org Cc: linux-tip-commits@vger.kernel.org, Josh Poimboeuf , x86@kernel.org Subject: Re: [tip: objtool/core] x86: Convert unreachable() to BUG() Message-ID: <20241216093215.GD12338@noisy.programming.kicks-ass.net> References: <20241128094312.028316261@infradead.org> <173313812188.412.17754446990942244796.tip-bot2@tip-bot2> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <173313812188.412.17754446990942244796.tip-bot2@tip-bot2> On Mon, Dec 02, 2024 at 11:15:21AM -0000, tip-bot2 for Peter Zijlstra wrote: > The following commit has been merged into the objtool/core branch of tip: > > Commit-ID: 2190966fbc14ca2cd4ea76eefeb96a47d8e390df > Gitweb: https://git.kernel.org/tip/2190966fbc14ca2cd4ea76eefeb96a47d8e390df > Author: Peter Zijlstra > AuthorDate: Thu, 28 Nov 2024 10:39:02 +01:00 > Committer: Peter Zijlstra > CommitterDate: Mon, 02 Dec 2024 12:01:43 +01:00 > > x86: Convert unreachable() to BUG() > > Avoid unreachable() as it can (and will in the absence of UBSAN) > generate fallthrough code. Use BUG() so we get a UD2 trap (with > unreachable annotation). > > Signed-off-by: Peter Zijlstra (Intel) > Acked-by: Josh Poimboeuf > Link: https://lore.kernel.org/r/20241128094312.028316261@infradead.org Urgh, one got lost: vmlinux.o: warning: objtool: page_fault_oops() falls through to next function is_prefetch() --- arch/x86/mm/fault.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index e6c469b323cc..ac52255fab01 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -678,7 +678,7 @@ page_fault_oops(struct pt_regs *regs, unsigned long error_code, ASM_CALL_ARG3, , [arg1] "r" (regs), [arg2] "r" (address), [arg3] "r" (&info)); - unreachable(); + BUG(); } #endif