From patchwork Wed Mar 30 08:16:59 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Zhengyu X-Patchwork-Id: 12795578 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 A1293C433F5 for ; Wed, 30 Mar 2022 08:20:12 +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=B+opzSn62u08oSn+utmYGRa9rXN1RC/ydHsX3tNiIYs=; b=PCfCt8vs6UUhFA pTXCnpcZn7sw5LB5yCfUv1UXFEVPa13nrR3JCkTCtZxLstV0F6zvYhNdkKjnYNkb40eqwO/7VjAmh tHmjrEs5WgwrRl2Og8k+XZeWY7UltFPjVGZvnquUYmHLWxiG0wqaVVNJ12lHTZ4PXJr7MQxceAUoj HMCleMThm1jVt2F2MFpE/Qq14n0v1myUyYcb9h38VRQ9j2Z/glzNB7Da+7Cmm2MPECRLr8I+nU8mH Zo0x4EMTwUVNOOyPW38qgX9hbIw/4zzAtoAjcvaVCk5Zi2EkV28cxyOLcl9Y3YzaIXnXHWQawdR13 vXzrtuUjQrtdIck28ZOw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nZTYh-00Em7K-Va; Wed, 30 Mar 2022 08:20:04 +0000 Received: from szxga02-in.huawei.com ([45.249.212.188]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nZTWZ-00Ekkv-GV; Wed, 30 Mar 2022 08:17:54 +0000 Received: from kwepemi500014.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4KSzl824KVzDq5r; Wed, 30 Mar 2022 16:15:32 +0800 (CST) Received: from huawei.com (10.67.174.157) by kwepemi500014.china.huawei.com (7.221.188.232) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Wed, 30 Mar 2022 16:17:44 +0800 From: Li Zhengyu To: CC: , , , , , , , , , , , , , , , Subject: [PATCH v2 -next 4/6] RISC-V: Support for kexec_file on panic Date: Wed, 30 Mar 2022 16:16:59 +0800 Message-ID: <20220330081701.177026-5-lizhengyu3@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220330081701.177026-1-lizhengyu3@huawei.com> References: <20220330081701.177026-1-lizhengyu3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.174.157] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemi500014.china.huawei.com (7.221.188.232) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220330_011751_955517_723D7871 X-CRM114-Status: GOOD ( 16.51 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org This patch adds support for loading a kexec on panic (kdump) kernel. It has been tested with vmcore-dmesg on riscv64 QEMU on both an smp and a non-smp system. Signed-off-by: Li Zhengyu --- arch/riscv/kernel/elf_kexec.c | 119 +++++++++++++++++++++++++++++++++- 1 file changed, 118 insertions(+), 1 deletion(-) diff --git a/arch/riscv/kernel/elf_kexec.c b/arch/riscv/kernel/elf_kexec.c index 2d442a849871..911d65d5a123 100644 --- a/arch/riscv/kernel/elf_kexec.c +++ b/arch/riscv/kernel/elf_kexec.c @@ -18,6 +18,8 @@ #include #include #include +#include +#include static int riscv_kexec_elf_load(struct kimage *image, struct elfhdr *ehdr, struct kexec_elf_info *elf_info, unsigned long old_pbase, @@ -97,6 +99,79 @@ static int elf_find_pbase(struct kimage *image, unsigned long kernel_len, return ret; } +static int get_nr_ram_ranges_callback(struct resource *res, void *arg) +{ + unsigned int *nr_ranges = arg; + + (*nr_ranges)++; + return 0; +} + +static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg) +{ + struct crash_mem *cmem = arg; + + cmem->ranges[cmem->nr_ranges].start = res->start; + cmem->ranges[cmem->nr_ranges].end = res->end; + cmem->nr_ranges++; + + return 0; +} + +static int prepare_elf_headers(void **addr, unsigned long *sz) +{ + struct crash_mem *cmem; + unsigned int nr_ranges; + int ret; + + nr_ranges = 1; /* For exclusion of crashkernel region */ + walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback); + + cmem = kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL); + if (!cmem) + return -ENOMEM; + + cmem->max_nr_ranges = nr_ranges; + cmem->nr_ranges = 0; + ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback); + if (ret) + goto out; + + /* Exclude crashkernel region */ + ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end); + if (!ret) + ret = crash_prepare_elf64_headers(cmem, true, addr, sz); + +out: + kfree(cmem); + return ret; +} + +static char *setup_kdump_cmdline(struct kimage *image, char *cmdline, + unsigned long cmdline_len) +{ + int elfcorehdr_strlen; + char *cmdline_ptr; + + cmdline_ptr = kzalloc(COMMAND_LINE_SIZE, GFP_KERNEL); + if (!cmdline_ptr) + return NULL; + + elfcorehdr_strlen = sprintf(cmdline_ptr, "elfcorehdr=0x%lx ", + image->elf_load_addr); + + if (elfcorehdr_strlen + cmdline_len > COMMAND_LINE_SIZE) { + pr_err("Appending elfcorehdr= exceeds cmdline size\n"); + kfree(cmdline_ptr); + return NULL; + } + + memcpy(cmdline_ptr + elfcorehdr_strlen, cmdline, cmdline_len); + /* Ensure it's nul terminated */ + cmdline_ptr[COMMAND_LINE_SIZE - 1] = '\0'; + return cmdline_ptr; +} + static void *elf_kexec_load(struct kimage *image, char *kernel_buf, unsigned long kernel_len, char *initrd, unsigned long initrd_len, char *cmdline, @@ -106,10 +181,12 @@ static void *elf_kexec_load(struct kimage *image, char *kernel_buf, unsigned long old_kernel_pbase = ULONG_MAX; unsigned long new_kernel_pbase = 0UL; unsigned long initrd_pbase = 0UL; - void *fdt; + unsigned long headers_sz; + void *fdt, *headers; struct elfhdr ehdr; struct kexec_buf kbuf; struct kexec_elf_info elf_info; + char *modified_cmdline = NULL; ret = kexec_build_elf_info(kernel_buf, kernel_len, &ehdr, &elf_info); if (ret) @@ -130,6 +207,45 @@ static void *elf_kexec_load(struct kimage *image, char *kernel_buf, kbuf.image = image; kbuf.buf_min = new_kernel_pbase + kernel_len; kbuf.buf_max = ULONG_MAX; + + /* Add elfcorehdr */ + if (image->type == KEXEC_TYPE_CRASH) { + ret = prepare_elf_headers(&headers, &headers_sz); + if (ret) { + pr_err("Preparing elf core header failed\n"); + goto out; + } + + kbuf.buffer = headers; + kbuf.bufsz = headers_sz; + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; + kbuf.memsz = headers_sz; + kbuf.buf_align = ELF_CORE_HEADER_ALIGN; + kbuf.top_down = true; + + ret = kexec_add_buffer(&kbuf); + if (ret) { + vfree(headers); + goto out; + } + image->elf_headers = headers; + image->elf_load_addr = kbuf.mem; + image->elf_headers_sz = headers_sz; + + pr_debug("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n", + image->elf_load_addr, kbuf.bufsz, kbuf.memsz); + + /* Setup cmdline for kdump kernel case */ + modified_cmdline = setup_kdump_cmdline(image, cmdline, + cmdline_len); + if (!modified_cmdline) { + pr_err("Setting up cmdline for kdump kernel failed\n"); + ret = -EINVAL; + goto out; + } + cmdline = modified_cmdline; + } + /* Add the initrd to the image */ if (initrd != NULL) { kbuf.buffer = initrd; @@ -170,6 +286,7 @@ static void *elf_kexec_load(struct kimage *image, char *kernel_buf, out_free_fdt: kvfree(fdt); out: + kfree(modified_cmdline); kexec_free_elf_info(&elf_info); return ret ? ERR_PTR(ret) : NULL; }