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 990F4101EE; Thu, 31 Jul 2025 17:56:59 +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=1753984619; cv=none; b=iVhsA6EHOpnYV5bifQo3mH8wfrFj+KjQxAkTB6JYX17+tSYdwtftR0WKsO9spV+D/g2K8fClgEwzq9gh0xWTe/+R+92byboDg4oyjkjWpvwohUxVGb2/ka8NtoM8eKtxGakp3hlMlE18Q48e4yLsHTAullSMtZnIXUaGHB19A9o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753984619; c=relaxed/simple; bh=UTAAwnNkZ8F8gFc4HNTNbB9l77CKuJmWmx5EcGTJ0SA=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=VTa0DABrZzBH0usONpux6quKm96eXBUDmPcwTjuaHkGnC6DMu0LVWCI4ETLmIg7w0ttOinmjH3GU7b3zFXxHpV37W47FbJN0EKJQZkaUV/16IE7JzONbU2Je6FonHdr7YNf82jOS1QHq8RMHcHuSe45RBulHgiq3g4ovxx0oUSc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=O1U5NX3+; 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="O1U5NX3+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A2E9C4CEEF; Thu, 31 Jul 2025 17:56:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753984619; bh=UTAAwnNkZ8F8gFc4HNTNbB9l77CKuJmWmx5EcGTJ0SA=; h=Date:From:To:Cc:Subject:From; b=O1U5NX3+T768JIi9YNuGY1AHv+77UKb4rM6WeyA7nw28hqUkxIbzsJi5WiPKQ1Y/e 30bRBti4XPZ3sOslwVn5E670UioHqY7DxkpPIRW9CXHU+Nfr5eQjV0+vMT9VsCr8my EvYbKD1n+qEsO/Yr1Khy3nB9r7QdRG+QD9W97HIoI9RWwAK7WYfzRYU07g09uaZq8q u5RuCYztXU+q6z6j+Qew4Q1jCIlEKR63vCI+NmaLQ77vOW86m54uOCLYDDFfam3UbK fIU6nhF88k/l9zUDOdd7Dzfbr+9znN4REj5NFjdtcbPqqvzBsyetQEYuS2TXlmHMZg Bwcfdl7LfqYMA== Date: Thu, 31 Jul 2025 10:56:55 -0700 From: Nathan Chancellor To: Huacai Chen , WANG Xuerui , WANG Rui Cc: loongarch@lists.linux.dev, llvm@lists.linux.dev Subject: objtool warnings "sibling call from callable instruction with modified stack frame" with CONFIG_LTO_CLANG_THIN Message-ID: <20250731175655.GA1455142@ax162> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi LoongArch folks, The kernel test robot recently generated several reports when building with LLVM that appear to be related (the "warning: objtool:" reports): https://lore.kernel.org/all/?q=loongarch-randconfig-002-20250730 This can be easily reproduced by enabling CONFIG_LTO_CLANG_THIN on top of defconfig: $ make -skj"$(nproc)" ARCH=loongarch LLVM=1 clean defconfig $ scripts/config -d LTO_NONE -e LTO_CLANG_THIN $ make -skj"$(nproc)" ARCH=loongarch LLVM=1 olddefconfig all drivers/char/ipmi/ipmi_devintf.o: warning: objtool: ipmi_ioctl+0x7c: sibling call from callable instruction with modified stack frame net/802/garp.o: warning: objtool: garp_pdu_rcv+0x170: sibling call from callable instruction with modified stack frame drivers/rapidio/devices/rio_mport_cdev.o: warning: objtool: mport_cdev_ioctl+0xe4: sibling call from callable instruction with modified stack frame net/802/mrp.o: warning: objtool: mrp_attr_event+0x5c: sibling call from callable instruction with modified stack frame net/netfilter/nfnetlink_osf.o: warning: objtool: nf_osf_match_one+0x1ac: unreachable instruction arch/loongarch/kvm/kvm.o: warning: objtool: kvm_set_memslot+0x22c: sibling call from callable instruction with modified stack frame arch/loongarch/kvm/kvm.o: warning: objtool: kvm_dev_ioctl+0x68: sibling call from callable instruction with modified stack frame arch/loongarch/kvm/kvm.o: warning: objtool: kvm_emu_iocsr+0x74: sibling call from callable instruction with modified stack frame arch/loongarch/kvm/kvm.o: warning: objtool: kvm_emu_mmio_read+0x58: sibling call from callable instruction with modified stack frame arch/loongarch/kvm/kvm.o: warning: objtool: kvm_emu_mmio_write+0x114: sibling call from callable instruction with modified stack frame arch/loongarch/kvm/kvm.o: warning: objtool: kvm_handle_gspr.llvm.8483686505109456213+0x230: sibling call from callable instruction with modified stack frame arch/loongarch/kvm/kvm.o: warning: objtool: kvm_arch_vcpu_ioctl+0x3ac: sibling call from callable instruction with modified stack frame arch/loongarch/kvm/kvm.o: warning: objtool: kvm_arch_vm_ioctl+0xec: sibling call from callable instruction with modified stack frame arch/loongarch/kvm/kvm.o: warning: objtool: kvm_ipi_read+0xe8: sibling call from callable instruction with modified stack frame arch/loongarch/kvm/kvm.o: warning: objtool: kvm_ipi_write+0x12c: sibling call from callable instruction with modified stack frame arch/loongarch/kvm/kvm.o: warning: objtool: kvm_ipi_regs_access+0x84: sibling call from callable instruction with modified stack frame arch/loongarch/kvm/kvm.o: warning: objtool: kvm_eiointc_regs_access+0x50: sibling call from callable instruction with modified stack frame arch/loongarch/kvm/kvm.o: warning: objtool: kvm_pch_pic_regs_access+0x54: sibling call from callable instruction with modified stack frame arch/loongarch/kvm/kvm.o: warning: objtool: kvm_pch_pic_read+0x64: sibling call from callable instruction with modified stack frame arch/loongarch/kvm/kvm.o: warning: objtool: kvm_pch_pic_write+0x7c: sibling call from callable instruction with modified stack frame drivers/char/ipmi/ipmi_si.o: warning: objtool: smi_event_handler+0x120: sibling call from callable instruction with modified stack frame drivers/char/ipmi/ipmi_si.o: warning: objtool: kcs_event.llvm.13474012466233770392+0x140: sibling call from callable instruction with modified stack frame ... x86_64 does not see these objtool warnings when LTO is enabled, is this a backend issue or does objtool need to account for something that LLVM does yet GCC does not? Cheers, Nathan