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 EECBC8BFF; Mon, 9 Jun 2025 08:27:48 +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=1749457669; cv=none; b=qlJuSazGmuC0Y2VWGRFn/NYYfzBqVIoGxsMKXBQTqlH6/3Cd8KVjkoIswH5JksGvzehZXVDde6hoRK96h+Jp55Hj+zImikpnErouNVO2xl9iSoaHA159nB1H8eWOdh6kafxcegbie5UzDbsTQbem8LK+AnFG6NW3pze5Nn/4OoU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749457669; c=relaxed/simple; bh=4sH/XwtN6/zyhtM9A103j8Ru62ZnMr73mTEUim9z6dI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PH+WrJuZ06UP7/kN9MZplCOsdUhe6VhrYO6oDfbSBVQzSp35C7zU9RqtDovEjLN60XR6QZhOrIeLs1y0hq6h6YteiXVbSik3nFsKD9U78+GLHwS+bhwnKRfKyCjG3kanhv1HvjZKqHeOBbPXOrMO93e+ReV2qhLMB+IyMl+RiaQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=T3tPh7Dj; 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="T3tPh7Dj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9984AC4CEEB; Mon, 9 Jun 2025 08:27:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749457668; bh=4sH/XwtN6/zyhtM9A103j8Ru62ZnMr73mTEUim9z6dI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=T3tPh7DjASMZscBcYz4H0Lo96hbRJ6mqF6+RNvufiWIhZpMYHOFvA4Pt/wJGsmWcq xqFTu4AHz+6jrjtrYVJBz+kZpDRyNUeefpyg2ptq8ltNILiO0ZEijWRJpabk7zGkso gSvNZM0Ng2mdGcNMmO94Wfxa275qZDAUzoDionR/902lFFga6Pxr2qa5J1cE+Cvp/I lourn3ffAxnLYhjx+n4F8FvRyk/tN8myutkBveTQC8KzZOtVLGHRZoHBXfDIBcj7Xi wrDnAQG4pkoEn37ITsMqzAN1tkSS/gs7zC3vFLJHtZeEM8J7qdHMGw4zzmWPd9H0WG ZJixSbJlAbHIQ== Date: Mon, 9 Jun 2025 10:27:44 +0200 From: Ingo Molnar To: Heiko Carstens Cc: linux-kernel@vger.kernel.org, Linus Torvalds , Peter Zijlstra , linux-arch@vger.kernel.org, Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , linux-s390@vger.kernel.org Subject: [PATCH 16/15] bugs/s390: Use in 'cond_str' to __EMIT_BUG() Message-ID: References: <20250515124644.2958810-1-mingo@kernel.org> <20250515124644.2958810-11-mingo@kernel.org> <20250520133927.7932C19-hca@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-arch@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: <20250520133927.7932C19-hca@linux.ibm.com> * Heiko Carstens wrote: > On Thu, May 15, 2025 at 02:46:39PM +0200, Ingo Molnar wrote: > > Pass in the condition string from __WARN_FLAGS(), but do not > > concatenate it with __FILE__, because the __bug_table is > > apparently indexed by 16 bits and increasing string size > > overflows it on defconfig builds. > > Could you provide your change which didn't work? > > I cannot see how anything would overflow. Trying the below on top of > your series seems to work like expected. > > In order to keep things easy this drops the mergeable section trick > and results in a small increase of the rodata section, but I doubt > that would explain what you have seen. > > Also allyesconfig builds without errors. > > diff --git a/arch/s390/include/asm/bug.h b/arch/s390/include/asm/bug.h > index 30f8785a01f5..837bfbde0c51 100644 > --- a/arch/s390/include/asm/bug.h > +++ b/arch/s390/include/asm/bug.h > @@ -11,16 +11,14 @@ > #define __EMIT_BUG(cond_str, x) do { \ > asm_inline volatile( \ > "0: mc 0,0\n" \ > - ".section .rodata.str,\"aMS\",@progbits,1\n" \ > - "1: .asciz \""__FILE__"\"\n" \ > - ".previous\n" \ > ".section __bug_table,\"aw\"\n" \ > - "2: .long 0b-.\n" \ > - " .long 1b-.\n" \ > - " .short %0,%1\n" \ > - " .org 2b+%2\n" \ > + "1: .long 0b-.\n" \ > + " .long %0-.\n" \ > + " .short %1,%2\n" \ > + " .org 1b+%3\n" \ > ".previous\n" \ > - : : "i" (__LINE__), \ > + : : "i" (WARN_CONDITION_STR(cond_str) __FILE__),\ > + "i" (__LINE__), \ > "i" (x), \ > "i" (sizeof(struct bug_entry))); \ > } while (0) So I'm not sure what happened: I tried to reproduce what I did originally, but my naive patch ran into assembler build errors when a WARN_ON() macro tried to use the '%' C operator, such as fs/crypto/crypto.c:123: include/linux/compiler_types.h:497:20: error: invalid 'asm': invalid %-code arch/s390/include/asm/bug.h:12:2: note: in expansion of macro 'asm_inline' arch/s390/include/asm/bug.h:50:2: note: in expansion of macro '__EMIT_BUG' include/asm-generic/bug.h:119:3: note: in expansion of macro '__WARN_FLAGS' fs/crypto/crypto.c:123:6: note: in expansion of macro 'WARN_ON_ONCE' Which corresponds to: if (WARN_ON_ONCE(len % FSCRYPT_CONTENTS_ALIGNMENT != 0)) return -EINVAL; I'm quite sure I never saw these build errors - I saw linker errors related to the u16 overflow I documented in the changelog. (Note to self: copy & paste more of the build error context next time around.) Your version doesn't have that build problem, so I picked it up with the changelog below and your Signed-off-by. Does that look good to you? Thanks, Ingo ===================================> >From 7128294ca8b997efb1d85c7405c8c6e9af1a170d Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 20 May 2025 15:39:27 +0200 Subject: [PATCH] bugs/s390: Use 'cond_str' in __EMIT_BUG() In order to keep things easy this drops the mergeable section trick and results in a small increase of the rodata section. Signed-off-by: Heiko Carstens Signed-off-by: Ingo Molnar Cc: Linus Torvalds Cc: Peter Zijlstra Cc: linux-arch@vger.kernel.org Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Cc: linux-s390@vger.kernel.org Link: https://lore.kernel.org/r/20250520133927.7932C19-hca@linux.ibm.com --- arch/s390/include/asm/bug.h | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/arch/s390/include/asm/bug.h b/arch/s390/include/asm/bug.h index 30f8785a01f5..837bfbde0c51 100644 --- a/arch/s390/include/asm/bug.h +++ b/arch/s390/include/asm/bug.h @@ -11,16 +11,14 @@ #define __EMIT_BUG(cond_str, x) do { \ asm_inline volatile( \ "0: mc 0,0\n" \ - ".section .rodata.str,\"aMS\",@progbits,1\n" \ - "1: .asciz \""__FILE__"\"\n" \ - ".previous\n" \ ".section __bug_table,\"aw\"\n" \ - "2: .long 0b-.\n" \ - " .long 1b-.\n" \ - " .short %0,%1\n" \ - " .org 2b+%2\n" \ + "1: .long 0b-.\n" \ + " .long %0-.\n" \ + " .short %1,%2\n" \ + " .org 1b+%3\n" \ ".previous\n" \ - : : "i" (__LINE__), \ + : : "i" (WARN_CONDITION_STR(cond_str) __FILE__),\ + "i" (__LINE__), \ "i" (x), \ "i" (sizeof(struct bug_entry))); \ } while (0)