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 C28FF1519A3; Fri, 7 Mar 2025 21:26:30 +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=1741382790; cv=none; b=KxbNjFDO9N/aAU5eZMH9Plf9JjF/LmqWpX97svc0o5wZ+23RjfMx1Ldiq9/Fa8bTPzLNw8v9r5JxK7QNY55T+KHwi8rsAXI/O6qWcltF0Qjz9bsn7wN0XYEIx/xlPEN0UaSI2jira4YG4kYMc5zlrwBBziBthlR4z2fseJQSi60= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741382790; c=relaxed/simple; bh=AghlRP1hPF0PIFr70gnDNCaE0UGvZVqXErTE3N+ofkc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=chCLQWMMp6h5ZoXyOr/SenX2eL7Eomx0npJOYcyLPulZfYs9eQpvbHDO1k8lgTUcF9UUW45uOmrnTWDi9UE74/bhmun+RZGpCEv5hMsDKbuwgso3HReUatd6yc98X6maqJdWY/xrVbq8PWDE4I1AblXEQ3XRNqILCbG4BUVZtuo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UyGoDuq7; 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="UyGoDuq7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5FF3C4CED1; Fri, 7 Mar 2025 21:26:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741382790; bh=AghlRP1hPF0PIFr70gnDNCaE0UGvZVqXErTE3N+ofkc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=UyGoDuq7blr4CbjrzwcocsNg3cbCgzPe/h6/sWLQBBwHg5hb/klDiJPG2/DYYULBt M8M3Yee7g6NdfMHXaUFFe/WIL/FXeVS+zsoiSUZhJ2zQ9grcoQJCMlelKtNb5y+N5j GYrkWaduYOTKEFLVUYYVDACzHkp/I3Yg/QefBNxjrvGQQLdwGzF0doArDgb+EXdfrx 070m0iCwdrRG47ZWvcYKyCmGH71Fsl4ieo6o65qeMVGSDvorF5vpdERsB/lKs6oH1/ wGSUlkvw14FrRsjT2s+ip82aHV+YyfhZxAs6s2urhZqL0SqsamOD5tjPKa7vS9tI0N P0TQnUOID1m1w== Date: Fri, 7 Mar 2025 22:26:25 +0100 From: Nathan Chancellor To: Greg Kroah-Hartman Cc: stable@vger.kernel.org, patches@lists.linux.dev, "Peter Zijlstra (Intel)" , Josh Poimboeuf , Sasha Levin Subject: Re: [PATCH 6.13 070/157] objtool: Remove annotate_{,un}reachable() Message-ID: <20250307212625.GA2700602@ax162> References: <20250305174505.268725418@linuxfoundation.org> <20250305174508.115393593@linuxfoundation.org> Precedence: bulk X-Mailing-List: stable@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: <20250305174508.115393593@linuxfoundation.org> On Wed, Mar 05, 2025 at 06:48:26PM +0100, Greg Kroah-Hartman wrote: > 6.13-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Peter Zijlstra > > [ Upstream commit 06e24745985c8dd0da18337503afcf2f2fdbdff1 ] > > There are no users of annotate_reachable() left. This is not true in 6.13.y because it was taken without upstream commit 624bde3465f6 ("loongarch: Use ASM_REACHABLE"), resulting in: In file included from include/linux/bug.h:5, from include/linux/thread_info.h:13, from include/asm-generic/current.h:6, from ./arch/loongarch/include/generated/asm/current.h:1, from include/linux/sched.h:12, from arch/loongarch/kernel/asm-offsets.c:8: include/linux/thread_info.h: In function 'check_copy_size': arch/loongarch/include/asm/bug.h:47:9: error: implicit declaration of function 'annotate_reachable' [-Wimplicit-function-declaration] 47 | annotate_reachable(); \ | ^~~~~~~~~~~~~~~~~~ include/asm-generic/bug.h:113:17: note: in expansion of macro '__WARN_FLAGS' 113 | __WARN_FLAGS(BUGFLAG_ONCE | \ | ^~~~~~~~~~~~ include/linux/thread_info.h:262:13: note: in expansion of macro 'WARN_ON_ONCE' 262 | if (WARN_ON_ONCE(bytes > INT_MAX)) | ^~~~~~~~~~~~ when trying to build ARCH=loongarch now. That applies cleanly and resolves the build failure. > And the annotate_unreachable() usage in unreachable() is plain wrong; > it will hide dangerous fall-through code-gen. This may be reason enough to take this patch into stable... (but then why wasn't it Cc'd in the first place, the tip folks are usually good about that?) > Remove both. > > Signed-off-by: Peter Zijlstra (Intel) > Acked-by: Josh Poimboeuf > Link: https://lore.kernel.org/r/20241128094312.235637588@infradead.org > Stable-dep-of: 73cfc53cc3b6 ("objtool: Fix C jump table annotations for Clang") But I do not think avoiding the conflict generated by this patch is... With the "diff3" merge.conflictstyle setting in git, I only see this conflict in that change: /* Annotate a C jump table to allow objtool to follow the code flow */ <<<<<<< HEAD #define __annotate_jump_table __section(".rodata..c_jump_table,\"a\",@progbits #") ||||||| parent of 73cfc53cc3b6 (objtool: Fix C jump table annotations for Clang) #define __annotate_jump_table __section(".rodata..c_jump_table,\"a\",@progbits #") ======= #define __annotate_jump_table __section(".data.rel.ro.c_jump_table") >>>>>>> 73cfc53cc3b6 (objtool: Fix C jump table annotations for Clang) which seems incredibly simple to resolve without dragging in two extra patches. If we do want to keep this change in 6.13.y, maybe it would be worth dragging in 2190966fbc14 ("x86: Convert unreachable() to BUG()") 41a1e976623e ("x86/mm: Convert unreachable() to BUG()") as well? Cheers, Nathan