From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A84064437 for ; Sun, 21 Apr 2024 05:25:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713677144; cv=none; b=OMi5pJJGOUsZcpq5aCgwYakCokUWGix2rUzDWrfZuUbSNOGng3p51jUHHzquBvzEux6h1wWtGTmCJy1b8NhcoEb8Esl6bfKEjwCpcAhuM15uwLh0tFrO2OosqzMd5FW6MdvkfwscwZHtJJGElSIBZBHEcDffYyJoCp+ZZ9RFEBY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713677144; c=relaxed/simple; bh=8897UkikHcygbe4N3ix+irQK9I4HgjF9WNURVeDcTNs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TEEAioUryZWh8i3QltOgfaV2GFfXR3BHmqZ4JFE4emzLdmkYmoQtANSvLFty4lR12PXlcYm4eBXJ3sfpj9kckxgAPnK4uyUB8KROo89cdNDgoU1GDuSKJIed1+y40HPGoBn/PH+RNKtz9gIcqlmE+IIQNsjSBiZfOJrO7wxRFQE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fdsS0b1W; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fdsS0b1W" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA8FFC2BD10; Sun, 21 Apr 2024 05:25:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713677144; bh=8897UkikHcygbe4N3ix+irQK9I4HgjF9WNURVeDcTNs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fdsS0b1WJV6G/qdyQzYD9Pl8zYlOKJxpZ1Ayb/UU/a5MRpjpBgufPbw+Kt5rO+E7f tcyOGMQaTecPjubm7xtHmXAxRp6G4cj5/or209HBQ7qzrLg6oqboqSYZXsPncT9Wod FEG2cw1WFafbBJsGpc4v0n4MMxWOkqIiGGFv8Dp9Spz1IkJIOHnAKNd8fPmTJI/46j iSjJ8VgoodV2dZAYGY4NtGyudxs+8sIaYEn9QhgPefgYr8f25gbe9R5xxsAP+VdDhz 7Gp+kDNQIj9qzC8jcWBl6T8bxcRu/GzlU+5WEQE/VFajSy1eSyMmcjQ9APrUQFS/uZ ZGF2IgORgQqsw== Date: Sat, 20 Apr 2024 22:25:40 -0700 From: Josh Poimboeuf To: "Paul E. McKenney" Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Linus Torvalds , Daniel Sneddon , Pawan Gupta , Thomas Gleixner , Alexandre Chartre , Konrad Rzeszutek Wilk , Peter Zijlstra , Greg Kroah-Hartman , Sean Christopherson , Andrew Cooper , Dave Hansen , Nikolay Borisov , KP Singh , Waiman Long , Borislav Petkov , Ingo Molnar Subject: Re: [PATCH v4 3/5] x86/syscall: Mark exit[_group] syscall handlers __noreturn Message-ID: <20240421052540.w7gtahoko2qerhqq@treble> References: <3b99cb2919c88ab3d353337423b2f0f1b9173f0a.1713559768.git.jpoimboe@kernel.org> <0c410ba5-0e42-43b6-80b8-a69c5419a97d@paulmck-laptop> 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=utf-8 Content-Disposition: inline In-Reply-To: <0c410ba5-0e42-43b6-80b8-a69c5419a97d@paulmck-laptop> On Sat, Apr 20, 2024 at 06:58:58AM -0700, Paul E. McKenney wrote: > On Fri, Apr 19, 2024 at 02:09:49PM -0700, Josh Poimboeuf wrote: > > The direct-call syscall dispatch functions don't know that the exit() > > and exit_group() syscall handlers don't return. As a result the call > > sites aren't optimized accordingly. > > > > Fix that by marking those exit syscall declarations as __noreturn. > > > > Fixes the following warnings: > > > > vmlinux.o: warning: objtool: x64_sys_call+0x2804: __x64_sys_exit() is missing a __noreturn annotation > > vmlinux.o: warning: objtool: ia32_sys_call+0x29b6: __ia32_sys_exit_group() is missing a __noreturn annotation > > > > Fixes: 7390db8aea0d ("x86/bhi: Add support for clearing branch history at syscall entry") > > Reported-by: "Paul E. McKenney" > > Closes: https://lkml.kernel.org/lkml/6dba9b32-db2c-4e6d-9500-7a08852f17a3@paulmck-laptop > > Signed-off-by: Josh Poimboeuf > > Looks good, but it does not apply on top of current -next and I don't > trust myself to hand-apply it (something about having just got off of > a flight across the big pond). > > Could you please let me know what else do I need to pull in to be able > to cleanly apply this one? This patch has a dependency on an earlier patch in the set: https://lkml.kernel.org/lkml/982d05a2f669140f26500bee643011896d661094.1713559768.git.jpoimboe@kernel.org Though I think it's not a hard dependency and I could reverse the order of the patches if needed. -- Josh