From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (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 EECA12FD7C7 for ; Tue, 21 Oct 2025 08:18:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.156.1 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761034734; cv=none; b=dgdJAHqFUKKO81IaHRXoI28CAX1cP19fM7EQTnSqbIJcd5IqCvP3oPpSBvTiLKtiS6K/1cbriXjbmA3/8ckaOrn6ZlwQnno1sQNGbaCklwctdLERh8y2TGM7jgC0cidmmgVWxj/5vg/YoKW1xrs2fvbs051nDr9JQUO14oAL/+Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761034734; c=relaxed/simple; bh=zoeqtV3NnoVo3PA6cGT6899ushddTj4EG2RgqFSrRLg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ZA3hN+QocveHRVt7mLMnFvxvL9YuCMz5hI6LDHzi5vTmSPsRCajjMWwwM9nzd4wCT0YWduaUHBarecjR6OD1OXb194sZNx/0D3r5q/Uakwxm12S6KdnkxeltV76FcwSBrisxMas1maZ+HwxOnFvhU9tUs52he7+fI0Q9N4Op3GQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=P1qcbKaQ; arc=none smtp.client-ip=148.163.156.1 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="P1qcbKaQ" Received: from pps.filterd (m0353729.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 59L0bOeV001179; Tue, 21 Oct 2025 08:18:41 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=pp1; bh=L9fBm/ Whek+136auQz9DyT244vveoKj6ZQ7dh5ArAbg=; b=P1qcbKaQ8uXHTxSPk5ISZ5 4zlMXuZkCNkBMa/lfDrCZi7wwseJyzambA/shqMej2li3c7tfhGc3G0VIY4kK9SE uL/TK8Uab+6nLbQ+8DWGLSvdacU1Kpc8a2nZ0lfpxBYx1ZOtFv9LwxWblxDQCUbj ZPtzMND51yL/kQshJmQGZOe5jZEy47lUzQtKzzvlC2QdPRLZcLjO05Ygs0km51Aw Z0tL5G8y3A9LFQCHIXwZT5dqbZMv9+vZuV+pS5TkZYcTo6sC8i2JOweT/31skrM7 Tq38csvhH1QcXE6Epi6yBKoF6r9kQkN7IvXeKBtaGrHDl+YUoGAgiUNsSvwZ5dgw == Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 49v33f5urg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 21 Oct 2025 08:18:40 +0000 (GMT) Received: from m0353729.ppops.net (m0353729.ppops.net [127.0.0.1]) by pps.reinject (8.18.1.12/8.18.0.8) with ESMTP id 59L8HP4m000378; Tue, 21 Oct 2025 08:18:40 GMT Received: from ppma23.wdc07v.mail.ibm.com (5d.69.3da9.ip4.static.sl-reverse.com [169.61.105.93]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 49v33f5ur9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 21 Oct 2025 08:18:40 +0000 (GMT) Received: from pps.filterd (ppma23.wdc07v.mail.ibm.com [127.0.0.1]) by ppma23.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 59L88ZDa024953; Tue, 21 Oct 2025 08:18:39 GMT Received: from smtprelay02.fra02v.mail.ibm.com ([9.218.2.226]) by ppma23.wdc07v.mail.ibm.com (PPS) with ESMTPS id 49vpqjspwj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 21 Oct 2025 08:18:38 +0000 Received: from smtpav03.fra02v.mail.ibm.com (smtpav03.fra02v.mail.ibm.com [10.20.54.102]) by smtprelay02.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 59L8Ib1x49873330 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 21 Oct 2025 08:18:37 GMT Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0353820043; Tue, 21 Oct 2025 08:18:37 +0000 (GMT) Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4D11520040; Tue, 21 Oct 2025 08:18:34 +0000 (GMT) Received: from linux.ibm.com (unknown [9.39.24.196]) by smtpav03.fra02v.mail.ibm.com (Postfix) with ESMTPS; Tue, 21 Oct 2025 08:18:34 +0000 (GMT) Date: Tue, 21 Oct 2025 13:48:31 +0530 From: Vishal Chourasia To: Nathan Chancellor Cc: Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Nick Desaulniers , Bill Wendling , Justin Stitt , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH] powerpc/vmlinux.lds: Drop .interp description Message-ID: References: <20251018-ppc-fix-lld-interp-v1-1-a083de6dccc9@kernel.org> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20251018-ppc-fix-lld-interp-v1-1-a083de6dccc9@kernel.org> X-TM-AS-GCONF: 00 X-Authority-Analysis: v=2.4 cv=FMYWBuos c=1 sm=1 tr=0 ts=68f741e0 cx=c_pps a=3Bg1Hr4SwmMryq2xdFQyZA==:117 a=3Bg1Hr4SwmMryq2xdFQyZA==:17 a=IkcTkHD0fZMA:10 a=x6icFKpwvdMA:10 a=VkNPw1HP01LnGYTKEx00:22 a=CCpqsmhAAAAA:8 a=NEAV23lmAAAA:8 a=VwQbUJbxAAAA:8 a=VnNF1IyMAAAA:8 a=FAP-1WBkK2k5Bz30Sn0A:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 a=ul9cdbp4aOFLsgKbc677:22 a=cPQSjfK2_nFv0Q5t_7PE:22 X-Proofpoint-GUID: PUznJ_3OC0JPYd9aU5zX_VlguL7hWr96 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUxMDE4MDAyMiBTYWx0ZWRfX2NN4/pHCUp6m IUj9VOSHR3Vs497FgOot7qomd0Pc9yaTtu5BDqpcXPmlitueloi0Cb4zV+60D44yufbgI9uab5O 3wLXQtsBLWzTxNUcY4omsb0HovyW6zNVXSMMCnkTRpEgouETDUb/8iJxpet5xueVCR/VL9BEwcz psb3Pmb2dh32kvIfTGlWacNbJcR5VSAEduCdSfk5RjdwgR4uzDFVfcd9bIO0GRWshIHrYPd6FBK hvyMq/uMscveGxnHOFhwGPi1ekr4kI6WUIrfZ4p/OxfMkcpCDvIrbEtJrJQYsL5dSO68/5xfMEN dYVrR7gz6oarwwfwRncmM8or6mrMbSm8HdRN2q1TrvVtAmpiqPAoGH3O0j3XRst/rlbLZw0vNao 8y3XasGZEPRTVe+vihZzfZysmjVzHQ== X-Proofpoint-ORIG-GUID: 7lS_-1FnU6zD-yPA5X_Ge0v5bGE8S3z- X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.9,FMLib:17.12.80.40 definitions=2025-10-20_07,2025-10-13_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 impostorscore=0 priorityscore=1501 adultscore=0 bulkscore=0 lowpriorityscore=0 suspectscore=0 phishscore=0 spamscore=0 malwarescore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2510020000 definitions=main-2510180022 On Sat, Oct 18, 2025 at 06:52:40PM +0100, Nathan Chancellor wrote: > Commit da30705c4621 ("arch/powerpc: Remove .interp section in vmlinux") > intended to drop the .interp section from vmlinux but even with this > change, relocatable kernels linked with ld.lld contain an empty .interp > section, which ends up causing crashes in GDB [1]. > > $ make -skj"$(nproc)" ARCH=powerpc LLVM=1 clean pseries_le_defconfig vmlinux > > $ llvm-readelf -S vmlinux | grep interp > [44] .interp PROGBITS c0000000021ddb34 21edb34 000000 00 A 0 0 1 > > There appears to be a subtle difference between GNU ld and ld.lld when > it comes to discarding sections that specify load addresses [2]. > > Since '--no-dynamic-linker' prevents emission of the .interp section, > there is no need to describe it in the output sections of the vmlinux > linker script. Drop the .interp section description from vmlinux.lds.S > to avoid this issue altogether. > > Link: https://sourceware.org/bugzilla/show_bug.cgi?id=33481 [1] > Link: https://github.com/ClangBuiltLinux/linux/issues/2137 [2] > Reported-by: Vishal Chourasia > Closes: https://lore.kernel.org/20251013040148.560439-1-vishalc@linux.ibm.com/ > Signed-off-by: Nathan Chancellor > --- > arch/powerpc/kernel/vmlinux.lds.S | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S > index de6ee7d35cff..15850296c0a9 100644 > --- a/arch/powerpc/kernel/vmlinux.lds.S > +++ b/arch/powerpc/kernel/vmlinux.lds.S > @@ -330,7 +330,6 @@ SECTIONS > } > .hash : AT(ADDR(.hash) - LOAD_OFFSET) { *(.hash) } > .gnu.hash : AT(ADDR(.gnu.hash) - LOAD_OFFSET) { *(.gnu.hash) } > - .interp : AT(ADDR(.interp) - LOAD_OFFSET) { *(.interp) } > .rela.dyn : AT(ADDR(.rela.dyn) - LOAD_OFFSET) > { > __rela_dyn_start = .; > > --- > base-commit: 3a8660878839faadb4f1a6dd72c3179c1df56787 > change-id: 20251018-ppc-fix-lld-interp-1a78c361cd42 > With this patch, I don't see .interp section being emitted the final vmlinux binary. ``` (i) ❯ make LLVM=1 vmlinux (i) ❯ llvm-readelf -p .comment vmlinux String dump of section '.comment': [ 1] clang version 22.0.0git (https://github.com/llvm/llvm-project.git 7314565281ec28b745502c3f429fd431e16673eb) [ 6d] Linker: LLD 22.0.0 (https://github.com/llvm/llvm-project.git 7314565281ec28b745502c3f429fd431e16673eb) (i) ❯ llvm-readelf -p .interp vmlinux llvm-readelf: warning: 'vmlinux': could not find section '.interp' ``` Tested-by: Vishal Chourasia