From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 283F7C432BE for ; Tue, 27 Jul 2021 14:52:51 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EFD4661AF7 for ; Tue, 27 Jul 2021 14:52:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org EFD4661AF7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8JkO6ur2yTFAnF8G2ckWcmPcjQoFEMO96oqeeu/fCAo=; b=xUmEhrwv7/IyKC 2m++n+30nlrohI8TXD+JturRkeyNGMDxCl21TEQsYp55CqkywDafGFoJIPjPPwhx0SGmFjbbMfeUF TULBYcVUi5jpK3DltvpgT6Iu8sQJGIeZkti36GJeegegWjFkUZLZa1ITNliDmYBboGblKxVPR5Ms8 07rGt6GzRhIJJtznCQoSd2vEpfCsAmAuCqOwfQaq5vmlbcYPFGd3r8Lp70dccQMTmExLihaahjVfV tan5FrayB7C9m/1obxzQyPYzpUYSVLMDwh07ldZVuneaZ+N6/NHLJb0szz9VwmPUyeE+DmV4mlUS5 p6iBxzyOj3liY6nUY5IA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m8OOn-00F5sI-Gm; Tue, 27 Jul 2021 14:49:37 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m8OOb-00F5pE-TA for linux-arm-kernel@lists.infradead.org; Tue, 27 Jul 2021 14:49:27 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 190B261AFF; Tue, 27 Jul 2021 14:49:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1627397365; bh=czPyPIxu2PTKCugBK9YtQzlToUphKkxEXLs4PNmX7jg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S5U4Sw6RZr+k+Bx+qsSik83rWJ1gJ3J+Xnjocua3sMYzOKHbVYjQfC9+EelM8p+bs 4yYTcFQ7ggj7/9L/nDbgjY7ayt505P/zljlokLVPofqFMQrEvNVfoW9HMuU4TqA0Co TdN+v3mbVV1heJZaRF5cU7QERPA97113HBKPcg2JvNFknquwsyW9tlVacdjnIMqXSX giQafSwRthQmNq0eRh7VJskmn2tjqTQ0Upx5ScJFTxOr6ZLAaYFUTQjrmyn933A70S 74C6f/8vRnm4eN8EXBJeJORsy9hMmPFHVQgiyP9SqQifHV6cf8WoTCKh6RQ+RTwTdh dqfKPOvYSQEWw== From: Arnd Bergmann To: Andrew Morton Cc: Arnd Bergmann , Catalin Marinas , Will Deacon , Thomas Bogendoerfer , "James E.J. Bottomley" , Helge Deller , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , "David S. Miller" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Al Viro , "Eric W. Biederman" , Christoph Hellwig , Feng Tang , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v5 1/6] kexec: move locking into do_kexec_load Date: Tue, 27 Jul 2021 16:48:54 +0200 Message-Id: <20210727144859.4150043-2-arnd@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210727144859.4150043-1-arnd@kernel.org> References: <20210727144859.4150043-1-arnd@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210727_074926_113867_EB72FB7E X-CRM114-Status: GOOD ( 18.82 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Arnd Bergmann The locking is the same between the native and compat version of sys_kexec_load(), so it can be done in the common implementation to reduce duplication. Co-developed-by: Eric Biederman Co-developed-by: Christoph Hellwig Signed-off-by: Arnd Bergmann --- kernel/kexec.c | 44 ++++++++++++++++---------------------------- 1 file changed, 16 insertions(+), 28 deletions(-) diff --git a/kernel/kexec.c b/kernel/kexec.c index c82c6c06f051..9c7aef8f4bb6 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -110,6 +110,17 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments, unsigned long i; int ret; + /* + * Because we write directly to the reserved memory region when loading + * crash kernels we need a mutex here to prevent multiple crash kernels + * from attempting to load simultaneously, and to prevent a crash kernel + * from loading over the top of a in use crash kernel. + * + * KISS: always take the mutex. + */ + if (!mutex_trylock(&kexec_mutex)) + return -EBUSY; + if (flags & KEXEC_ON_CRASH) { dest_image = &kexec_crash_image; if (kexec_crash_image) @@ -121,7 +132,8 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments, if (nr_segments == 0) { /* Uninstall image */ kimage_free(xchg(dest_image, NULL)); - return 0; + ret = 0; + goto out_unlock; } if (flags & KEXEC_ON_CRASH) { /* @@ -134,7 +146,7 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments, ret = kimage_alloc_init(&image, entry, nr_segments, segments, flags); if (ret) - return ret; + goto out_unlock; if (flags & KEXEC_PRESERVE_CONTEXT) image->preserve_context = 1; @@ -171,6 +183,8 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments, arch_kexec_protect_crashkres(); kimage_free(image); +out_unlock: + mutex_unlock(&kexec_mutex); return ret; } @@ -247,21 +261,8 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, ((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT)) return -EINVAL; - /* Because we write directly to the reserved memory - * region when loading crash kernels we need a mutex here to - * prevent multiple crash kernels from attempting to load - * simultaneously, and to prevent a crash kernel from loading - * over the top of a in use crash kernel. - * - * KISS: always take the mutex. - */ - if (!mutex_trylock(&kexec_mutex)) - return -EBUSY; - result = do_kexec_load(entry, nr_segments, segments, flags); - mutex_unlock(&kexec_mutex); - return result; } @@ -301,21 +302,8 @@ COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry, return -EFAULT; } - /* Because we write directly to the reserved memory - * region when loading crash kernels we need a mutex here to - * prevent multiple crash kernels from attempting to load - * simultaneously, and to prevent a crash kernel from loading - * over the top of a in use crash kernel. - * - * KISS: always take the mutex. - */ - if (!mutex_trylock(&kexec_mutex)) - return -EBUSY; - result = do_kexec_load(entry, nr_segments, ksegments, flags); - mutex_unlock(&kexec_mutex); - return result; } #endif -- 2.29.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel