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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 7AF3CC7EE2F for ; Sat, 27 May 2023 12:36:07 +0000 (UTC) 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=ikVBRFt+XRr6Xb2MfBlgVjEO6G1a+cU/A3ZZmk4GPhQ=; b=486NKFpFcjTXkj X+YMdp1eJr65e3mmUWy8jvlC/NNAu6GQcN8LBHtFYctYlY2h17nUWlMxo9pMf7ds9TtJ2O23AKNFD F+cm3y6YmwgUfc5bwMaW0h4KIyjhy8KE2GqTfAvE6RVYtesgcHmgi5z6MnWUC7CuWObn9JL8MTBXY 2BBgwks5n9cQVh1EWPkbOprpdprdARZuhUYkNQp4xyWMHGhePwmuo7IUOJkAYawSXFsixAYiNPuQL NiEXPEfzjyuG+x7X9NJc3G9Lz1q9lHhFvYP/VEMLN75JpCV+P/lLEyDON0+JxdI7G1rUcZbEL1lK7 fQcPTtWk9LVNwDMV6oxQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q2t9Q-005io9-2a; Sat, 27 May 2023 12:36:04 +0000 Received: from szxga02-in.huawei.com ([45.249.212.188]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1q2t9K-005ijc-1s for kexec@lists.infradead.org; Sat, 27 May 2023 12:36:00 +0000 Received: from dggpemm500006.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4QT1Qr6x5XzLpvb; Sat, 27 May 2023 20:32:52 +0800 (CST) Received: from thunder-town.china.huawei.com (10.174.178.55) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Sat, 27 May 2023 20:35:50 +0800 From: Zhen Lei To: Eric Biederman , Baoquan He , , CC: Zhen Lei , Michael Holzheu , Andrew Morton , Amerigo Wang Subject: [PATCH 6/6] kexec: enable kexec_crash_size to support two crash kernel regions Date: Sat, 27 May 2023 20:34:39 +0800 Message-ID: <20230527123439.772-7-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.37.3.windows.1 In-Reply-To: <20230527123439.772-1-thunder.leizhen@huawei.com> References: <20230527123439.772-1-thunder.leizhen@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230527_053559_641277_62279C56 X-CRM114-Status: GOOD ( 14.76 ) X-BeenThere: kexec@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: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org The crashk_low_res should be considered by /sys/kernel/kexec_crash_size to support two crash kernel regions. Since crashk_res manages the memory with high address and crashk_low_res manages the memory with low address, crashk_low_res is shrunken only when all crashk_res is shrunken. And because when there is only one crash kernel region, crashk_res is always used. Therefore, if all crashk_res is shrunken and crashk_low_res still exists, swap them. Signed-off-by: Zhen Lei --- kernel/kexec_core.c | 43 ++++++++++++++++++++++++++++++++++++++----- 1 file changed, 38 insertions(+), 5 deletions(-) diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index e82bc6d6634136a..c1d50f6566300d9 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -1091,6 +1091,11 @@ __bpf_kfunc void crash_kexec(struct pt_regs *regs) } } +static inline resource_size_t crash_resource_size(const struct resource *res) +{ + return !res->end ? 0 : resource_size(res); +} + ssize_t crash_get_memory_size(void) { ssize_t size = 0; @@ -1098,8 +1103,8 @@ ssize_t crash_get_memory_size(void) if (!kexec_trylock()) return -EBUSY; - if (crashk_res.end != crashk_res.start) - size = resource_size(&crashk_res); + size += crash_resource_size(&crashk_res); + size += crash_resource_size(&crashk_low_res); kexec_unlock(); return size; @@ -1135,7 +1140,7 @@ int __crash_shrink_memory(struct resource *old_res, unsigned long new_size) int crash_shrink_memory(unsigned long new_size) { int ret = 0; - unsigned long old_size; + unsigned long old_size, low_size; if (!kexec_trylock()) return -EBUSY; @@ -1144,14 +1149,42 @@ int crash_shrink_memory(unsigned long new_size) ret = -ENOENT; goto unlock; } - old_size = !crashk_res.end ? 0 : resource_size(&crashk_res); + + low_size = crash_resource_size(&crashk_low_res); + old_size = crash_resource_size(&crashk_res) + low_size; new_size = roundup(new_size, KEXEC_CRASH_MEM_ALIGN); if (new_size >= old_size) { ret = (new_size == old_size) ? 0 : -EINVAL; goto unlock; } - ret = __crash_shrink_memory(&crashk_res, new_size); + /* + * (low_size > new_size) implies that low_size is greater than zero. + * This also means that if low_size is zero, the else branch is taken. + * + * If low_size is greater than 0, (low_size > new_size) indicates that + * crashk_low_res also needs to be shrunken. Otherwise, only crashk_res + * needs to be shrunken. + */ + if (low_size > new_size) { + ret = __crash_shrink_memory(&crashk_res, 0); + if (ret) + goto unlock; + + ret = __crash_shrink_memory(&crashk_low_res, new_size); + } else { + ret = __crash_shrink_memory(&crashk_res, new_size - low_size); + } + + /* Swap crashk_res and crashk_low_res if needed */ + if (!crashk_res.end && crashk_low_res.end) { + crashk_res.start = crashk_low_res.start; + crashk_res.end = crashk_low_res.end; + release_resource(&crashk_low_res); + crashk_low_res.start = 0; + crashk_low_res.end = 0; + insert_resource(&iomem_resource, &crashk_res); + } unlock: kexec_unlock(); -- 2.25.1 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec