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[2001:1868:205::9]) by mx.google.com with ESMTPS id h187si489783pgc.329.2016.11.01.21.48.44 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 01 Nov 2016 21:48:44 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) client-ip=2001:1868:205::9; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@linaro.org; spf=pass (google.com: best guess record for domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) smtp.mailfrom=linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org; dmarc=fail (p=NONE dis=NONE) header.from=linaro.org Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1c1nSG-0005mJ-VA; Wed, 02 Nov 2016 04:47:16 +0000 Received: from mail-pf0-x236.google.com ([2607:f8b0:400e:c00::236]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1c1nQd-0003mT-TE for linux-arm-kernel@lists.infradead.org; Wed, 02 Nov 2016 04:45:44 +0000 Received: by mail-pf0-x236.google.com with SMTP id 189so4232129pfz.3 for ; Tue, 01 Nov 2016 21:45:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=kWDJlDsE8rpPHiUdY8M6hBxUTYXsnovuXOtrRUqVChQ=; b=McS2/W8PQKDCmQuqhPyAUqAGW2SeoWU5YByuA1BymjNMQ8/eR1DA6lLaXlSjazpDsn sqztXzKO0rFvqWkfa/Lr+fe7+gjpylDTerap/lYEMCYt0wQRMOluGEfXl8ZPSJGkcQMa snuvVIl9zpKb7Q1GsLjaUi2QZDR7yOoFLSeEw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=kWDJlDsE8rpPHiUdY8M6hBxUTYXsnovuXOtrRUqVChQ=; b=hQ8PmSOZSjxBwRMizsnsYl6cx7EtRDadV0spNrYSRXVVtK3KaLriQDvcEemmliAJm/ G17f/VACDVNqtZmdLP8zdO1BUx7v4UsKYR3iYbD6XgNg2bZGIfvIl+0BG5Tv8a6ttPpL e5Z8bfQoCsCSM1OE5OitQEVvx8RBCkjmSeY91eP+wpNTo9ufn88sv3bQhXX2aGoXClgA vazPRjvWEfrkaUAtVf04l6bZFjFwNyHFAGU2ugsSFbNlq5vz0FV9ThfpNd7eOybNNw5N Lo7jZcuT2OhUGPNCqrux8NwTzgMPRUpNd7oHzByr4W8ImU+YoSdNKIGyODJN0LRwnYBI 0XTg== X-Gm-Message-State: ABUngvc6e0NoW+i2hWPwd03y5Cgm0F2eezZJd2MaEQNHAy0aRppUh8RkS2Zk6wZMyU8afT+y X-Received: by 10.98.100.215 with SMTP id y206mr3209492pfb.49.1478061914771; Tue, 01 Nov 2016 21:45:14 -0700 (PDT) Received: from linaro.org ([121.95.100.191]) by smtp.googlemail.com with ESMTPSA id j192sm474007pfc.60.2016.11.01.21.45.14 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 01 Nov 2016 21:45:14 -0700 (PDT) From: AKASHI Takahiro To: catalin.marinas@arm.com, will.deacon@arm.com Subject: [PATCH v27 6/9] arm64: kdump: provide /proc/vmcore file Date: Wed, 2 Nov 2016 13:52:47 +0900 Message-Id: <20161102045249.12058-5-takahiro.akashi@linaro.org> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20161102044959.11954-1-takahiro.akashi@linaro.org> References: <20161102044959.11954-1-takahiro.akashi@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20161101_214536_457718_87171980 X-CRM114-Status: GOOD ( 25.84 ) X-Spam-Score: -2.7 (--) X-Spam-Report: SpamAssassin version 3.4.0 on bombadil.infradead.org summary: Content analysis details: (-2.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [2607:f8b0:400e:c00:0:0:0:236 listed in] [list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, geoff@infradead.org, kexec@lists.infradead.org, AKASHI Takahiro , james.morse@arm.com, bauerman@linux.vnet.ibm.com, dyoung@redhat.com, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org Add arch-specific functions to provide a dump file, /proc/vmcore. This file is in ELF format and its ELF header needs to be prepared by userspace tools, like kexec-tools, in adance. The primary kernel is responsible to allocate the region with reserve_elfcorehdr() at boot time and advertize its location to crash dump kernel via a new device-tree property, "linux,elfcorehdr". Then crash dump kernel will access the primary kernel's memory with copy_oldmem_page(), which feeds the data page-by-page by ioremap'ing it since it does not reside in linear mapping on crash dump kernel. We also need our own elfcorehdr_read() here since the header is placed within crash dump kernel's usable memory. Signed-off-by: AKASHI Takahiro Reviewed-by: James Morse --- arch/arm64/Kconfig | 11 +++++++ arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/crash_dump.c | 71 ++++++++++++++++++++++++++++++++++++++++++ arch/arm64/mm/init.c | 54 ++++++++++++++++++++++++++++++++ 4 files changed, 137 insertions(+) create mode 100644 arch/arm64/kernel/crash_dump.c -- 2.10.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 969ef88..399f84a 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -688,6 +688,17 @@ config KEXEC but it is independent of the system firmware. And like a reboot you can start any kernel with it, not just Linux. +config CRASH_DUMP + bool "Build kdump crash kernel" + help + Generate crash dump after being started by kexec. This should + be normally only set in special crash dump kernels which are + loaded in the main kernel with kexec-tools into a specially + reserved region and then later executed after a crash by + kdump/kexec. + + For more details see Documentation/kdump/kdump.txt + config XEN_DOM0 def_bool y depends on XEN diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 7d66bba..6a7384e 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -50,6 +50,7 @@ arm64-obj-$(CONFIG_RANDOMIZE_BASE) += kaslr.o arm64-obj-$(CONFIG_HIBERNATION) += hibernate.o hibernate-asm.o arm64-obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o \ cpu-reset.o +arm64-obj-$(CONFIG_CRASH_DUMP) += crash_dump.o obj-y += $(arm64-obj-y) vdso/ probes/ obj-m += $(arm64-obj-m) diff --git a/arch/arm64/kernel/crash_dump.c b/arch/arm64/kernel/crash_dump.c new file mode 100644 index 0000000..c3d5a21 --- /dev/null +++ b/arch/arm64/kernel/crash_dump.c @@ -0,0 +1,71 @@ +/* + * Routines for doing kexec-based kdump + * + * Copyright (C) 2014 Linaro Limited + * Author: AKASHI Takahiro + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include +#include + +/** + * copy_oldmem_page() - copy one page from old kernel memory + * @pfn: page frame number to be copied + * @buf: buffer where the copied page is placed + * @csize: number of bytes to copy + * @offset: offset in bytes into the page + * @userbuf: if set, @buf is in a user address space + * + * This function copies one page from old kernel memory into buffer pointed by + * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes + * copied or negative error in case of failure. + */ +ssize_t copy_oldmem_page(unsigned long pfn, char *buf, + size_t csize, unsigned long offset, + int userbuf) +{ + void *vaddr; + + if (!csize) + return 0; + + vaddr = memremap(__pfn_to_phys(pfn), PAGE_SIZE, MEMREMAP_WB); + if (!vaddr) + return -ENOMEM; + + if (userbuf) { + if (copy_to_user((char __user *)buf, vaddr + offset, csize)) { + memunmap(vaddr); + return -EFAULT; + } + } else { + memcpy(buf, vaddr + offset, csize); + } + + memunmap(vaddr); + + return csize; +} + +/** + * elfcorehdr_read - read from ELF core header + * @buf: buffer where the data is placed + * @csize: number of bytes to read + * @ppos: address in the memory + * + * This function reads @count bytes from elf core header which exists + * on crash dump kernel's memory. + */ +ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos) +{ + memcpy(buf, phys_to_virt((phys_addr_t)*ppos), count); + return count; +} diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 1d62bf7..ef8adfd 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -38,6 +38,7 @@ #include #include #include +#include #include #include @@ -183,6 +184,57 @@ static void __init reserve_crashkernel(void) } #endif /* CONFIG_KEXEC_CORE */ +#ifdef CONFIG_CRASH_DUMP +static int __init early_init_dt_scan_elfcorehdr(unsigned long node, + const char *uname, int depth, void *data) +{ + const __be32 *reg; + int len; + + if (depth != 1 || strcmp(uname, "chosen") != 0) + return 0; + + reg = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len); + if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells))) + return 1; + + elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, ®); + elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, ®); + + return 1; +} + +/* + * reserve_elfcorehdr() - reserves memory for elf core header + * + * This function reserves elf core header given in "elfcorehdr=" kernel + * command line parameter. This region contains all the information about + * primary kernel's core image and is used by a dump capture kernel to + * access the system memory on primary kernel. + */ +static void __init reserve_elfcorehdr(void) +{ + of_scan_flat_dt(early_init_dt_scan_elfcorehdr, NULL); + + if (!elfcorehdr_size) + return; + + if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) { + pr_warn("elfcorehdr is overlapped\n"); + return; + } + + memblock_reserve(elfcorehdr_addr, elfcorehdr_size); + + pr_info("Reserving %lldKB of memory at 0x%llx for elfcorehdr\n", + elfcorehdr_size >> 10, elfcorehdr_addr); +} +#else +static void __init reserve_elfcorehdr(void) +{ + ; +} +#endif /* CONFIG_CRASH_DUMP */ /* * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It * currently assumes that for memory starting above 4G, 32-bit devices will @@ -441,6 +493,8 @@ void __init arm64_memblock_init(void) reserve_crashkernel(); + reserve_elfcorehdr(); + dma_contiguous_reserve(arm64_dma_phys_limit); memblock_allow_resize();