From patchwork Mon Feb 26 11:17:18 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Philipp Rudo X-Patchwork-Id: 10242061 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C0122602DC for ; Mon, 26 Feb 2018 11:17:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B195729EFA for ; Mon, 26 Feb 2018 11:17:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A67DE29F4D; Mon, 26 Feb 2018 11:17:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 23B9329EFA for ; Mon, 26 Feb 2018 11:17:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Message-Id:MIME-Version:References: In-Reply-To:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=hBgyGMyJV7hbOqtbcc/gzAghCD+KUDci2ReRr4laGZ0=; b=YqZLN2LWqgWOtP OO0l+Y8Y1nsTb2iI0STLN9H36FIKKNn9DtiD7t4iM/ZtW/kkUzr36UpG8wwcxwgCSc8IMZhZOIXcv 0al42p5oEhf/FxoWD4gWzT1VAXx0buvJARAPOicFJqUiac8xsA8J44jBAfV4FcJ3z/Yl58dpVYN9m pblF1vUszTt6mJcDOQPs0HsSSZi1e1QyEKyG33auZFn/L45aIPDjzUed+vmEHA6+YbXSnD9QbrQ3c P5cwiZyEFg1czNU6QKSNji9lP6TOoyDktEH3jiIieyQYPXomv/Jopcl4OZ2wmpSOzbhQhqW7YJ8xB HmehJ9I4IRZaBAVSMNdQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.89 #1 (Red Hat Linux)) id 1eqGmz-00030G-O2; Mon, 26 Feb 2018 11:17:49 +0000 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5] helo=mx0a-001b2d01.pphosted.com) by bombadil.infradead.org with esmtps (Exim 4.89 #1 (Red Hat Linux)) id 1eqGms-0002wH-Vm for linux-arm-kernel@lists.infradead.org; Mon, 26 Feb 2018 11:17:45 +0000 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w1QBEAYN076266 for ; Mon, 26 Feb 2018 06:17:32 -0500 Received: from e06smtp11.uk.ibm.com (e06smtp11.uk.ibm.com [195.75.94.107]) by mx0b-001b2d01.pphosted.com with ESMTP id 2gcg9jtfnr-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 26 Feb 2018 06:17:31 -0500 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 26 Feb 2018 11:17:21 -0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w1QBHKZd47841378; Mon, 26 Feb 2018 11:17:20 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0EDEBA4053; Mon, 26 Feb 2018 11:10:26 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5DA34A4040; Mon, 26 Feb 2018 11:10:25 +0000 (GMT) Received: from ThinkPad (unknown [9.152.212.63]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 26 Feb 2018 11:10:25 +0000 (GMT) Date: Mon, 26 Feb 2018 12:17:18 +0100 From: Philipp Rudo To: AKASHI Takahiro Subject: Re: [PATCH v8 03/13] kexec_file, x86, powerpc: factor out kexec_file_ops functions In-Reply-To: <20180222111732.23051-4-takahiro.akashi@linaro.org> References: <20180222111732.23051-1-takahiro.akashi@linaro.org> <20180222111732.23051-4-takahiro.akashi@linaro.org> Organization: IBM X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 18022611-0040-0000-0000-00000437E848 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18022611-0041-0000-0000-000020DA0F03 Message-Id: <20180226121718.3432bbd6@ThinkPad> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2018-02-26_03:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1802260153 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180226_031743_144915_188DD361 X-CRM114-Status: GOOD ( 34.07 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: herbert@gondor.apana.org.au, bhe@redhat.com, ard.biesheuvel@linaro.org, catalin.marinas@arm.com, julien.thierry@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, dhowells@redhat.com, arnd@arndb.de, linux-arm-kernel@lists.infradead.org, mpe@ellerman.id.au, bauerman@linux.vnet.ibm.com, akpm@linux-foundation.org, dyoung@redhat.com, davem@davemloft.net, vgoyal@redhat.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Hi AKASHI On Thu, 22 Feb 2018 20:17:22 +0900 AKASHI Takahiro wrote: [...] > diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c > index 990adae52151..a6d14a768b3e 100644 > --- a/kernel/kexec_file.c > +++ b/kernel/kexec_file.c > @@ -26,34 +26,83 @@ > #include > #include "kexec_internal.h" > > +const __weak struct kexec_file_ops * const kexec_file_loaders[] = {NULL}; > + Having a weak definition of kexec_file_loaders causes trouble on s390 with gcc 4.8 (newer versions seem to work fine). For me it looks like that in this version gcc doesn't recognize __weak but use the default value for optimization. This leads to _kexec_kernel_image_probe to always return ENOEXEC because the for-loop gets optimized out. The problem can easily be worked around by declaring kexec_file_loaders in include/linux/kexec.h and defining it in arch code. In particular doing this A nice side effect of this solution is, that a developer who forgets to define kexec_file_loaders gets a linker error. So he directly knows what's missing instead of first having to find out where/why an error gets returned. Otherwise the series is fine for me. Thanks Philipp > #ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY > static int kexec_calculate_store_digests(struct kimage *image); > #else > static int kexec_calculate_store_digests(struct kimage *image) { return 0; }; > #endif > > +int _kexec_kernel_image_probe(struct kimage *image, void *buf, > + unsigned long buf_len) > +{ > + const struct kexec_file_ops * const *fops; > + int ret = -ENOEXEC; > + > + for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) { > + ret = (*fops)->probe(buf, buf_len); > + if (!ret) { > + image->fops = *fops; > + return ret; > + } > + } > + > + return ret; > +} > + > /* Architectures can provide this probe function */ > int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf, > unsigned long buf_len) > { > - return -ENOEXEC; > + return _kexec_kernel_image_probe(image, buf, buf_len); > +} > + > +void *_kexec_kernel_image_load(struct kimage *image) > +{ > + if (!image->fops || !image->fops->load) > + return ERR_PTR(-ENOEXEC); > + > + return image->fops->load(image, image->kernel_buf, > + image->kernel_buf_len, image->initrd_buf, > + image->initrd_buf_len, image->cmdline_buf, > + image->cmdline_buf_len); > } > > void * __weak arch_kexec_kernel_image_load(struct kimage *image) > { > - return ERR_PTR(-ENOEXEC); > + return _kexec_kernel_image_load(image); > +} > + > +int _kimage_file_post_load_cleanup(struct kimage *image) > +{ > + if (!image->fops || !image->fops->cleanup) > + return 0; > + > + return image->fops->cleanup(image->image_loader_data); > } > > int __weak arch_kimage_file_post_load_cleanup(struct kimage *image) > { > - return -EINVAL; > + return _kimage_file_post_load_cleanup(image); > } > > #ifdef CONFIG_KEXEC_VERIFY_SIG > +int _kexec_kernel_verify_sig(struct kimage *image, void *buf, > + unsigned long buf_len) > +{ > + if (!image->fops || !image->fops->verify_sig) { > + pr_debug("kernel loader does not support signature verification.\n"); > + return -EKEYREJECTED; > + } > + > + return image->fops->verify_sig(buf, buf_len); > +} > + > int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, > unsigned long buf_len) > { > - return -EKEYREJECTED; > + return _kexec_kernel_verify_sig(image, buf, buf_len); > } > #endif > diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 37e9dce518aa..fc0788540d90 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -139,6 +139,8 @@ struct kexec_file_ops { #endif }; +extern const struct kexec_file_ops * const kexec_file_loaders[]; + /** * struct kexec_buf - parameters for finding a place for a buffer in memory * @image: kexec image in which memory to search. diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 17ba407d0e79..4e3d1e4bc7f6 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -31,8 +31,6 @@ #include #include "kexec_internal.h" -const __weak struct kexec_file_ops * const kexec_file_loaders[] = {NULL}; - #ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY static int kexec_calculate_store_digests(struct kimage *image); #else