From patchwork Tue Aug 30 17:45:02 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thiago Jung Bauermann X-Patchwork-Id: 9305835 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 B4F8D60756 for ; Tue, 30 Aug 2016 17:48:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A6EA728CE9 for ; Tue, 30 Aug 2016 17:48:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9A18228CEB; Tue, 30 Aug 2016 17:48:43 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CE77228CE9 for ; Tue, 30 Aug 2016 17:48:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933526AbcH3RsC (ORCPT ); Tue, 30 Aug 2016 13:48:02 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:35688 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933613AbcH3RpV (ORCPT ); Tue, 30 Aug 2016 13:45:21 -0400 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u7UHhfYE095972 for ; Tue, 30 Aug 2016 13:45:20 -0400 Received: from e24smtp03.br.ibm.com (e24smtp03.br.ibm.com [32.104.18.24]) by mx0a-001b2d01.pphosted.com with ESMTP id 255363t00k-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 30 Aug 2016 13:45:20 -0400 Received: from localhost by e24smtp03.br.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Tue, 30 Aug 2016 14:45:16 -0300 X-IBM-Helo: d24dlp01.br.ibm.com X-IBM-MailFrom: bauerman@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org; linux-security-module@vger.kernel.org Received: from d24relay01.br.ibm.com (d24relay01.br.ibm.com [9.8.31.16]) by d24dlp01.br.ibm.com (Postfix) with ESMTP id 316B53520072; Tue, 30 Aug 2016 13:44:54 -0400 (EDT) Received: from d24av05.br.ibm.com (d24av05.br.ibm.com [9.18.232.44]) by d24relay01.br.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u7UHjGKM5062908; Tue, 30 Aug 2016 14:45:16 -0300 Received: from d24av05.br.ibm.com (localhost [127.0.0.1]) by d24av05.br.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u7UHjENK015679; Tue, 30 Aug 2016 14:45:16 -0300 Received: from hactar.ibm.com (lcfurno.br.ibm.com [9.18.203.1] (may be forged)) by d24av05.br.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u7UHjAVZ015449; Tue, 30 Aug 2016 14:45:13 -0300 From: Thiago Jung Bauermann To: kexec@lists.infradead.org Cc: linux-security-module@vger.kernel.org, linux-ima-devel@lists.sourceforge.net, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Eric Biederman , Dave Young , Vivek Goyal , Baoquan He , Michael Ellerman , Stewart Smith , Mimi Zohar , Eric Richter , Andrew Morton , Balbir Singh , Thiago Jung Bauermann Subject: [PATCH v4 2/5] powerpc: kexec_file: Add buffer hand-over support for the next kernel Date: Tue, 30 Aug 2016 14:45:02 -0300 X-Mailer: git-send-email 1.9.1 In-Reply-To: <1472579105-26296-1-git-send-email-bauerman@linux.vnet.ibm.com> References: <1472579105-26296-1-git-send-email-bauerman@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16083017-0024-0000-0000-000000F92D08 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16083017-0025-0000-0000-00001589E72F Message-Id: <1472579105-26296-3-git-send-email-bauerman@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2016-08-30_07:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=3 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1608300169 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP The buffer hand-over mechanism allows the currently running kernel to pass data to kernel that will be kexec'd via a kexec segment. The second kernel can check whether the previous kernel sent data and retrieve it. This is the architecture-specific part. Signed-off-by: Thiago Jung Bauermann --- arch/powerpc/include/asm/kexec.h | 12 +- arch/powerpc/kernel/kexec_elf_64.c | 2 +- arch/powerpc/kernel/machine_kexec_64.c | 274 +++++++++++++++++++++++++++------ 3 files changed, 240 insertions(+), 48 deletions(-) diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h index 73f88b5f9bd1..b8e32194ce63 100644 --- a/arch/powerpc/include/asm/kexec.h +++ b/arch/powerpc/include/asm/kexec.h @@ -92,12 +92,20 @@ static inline bool kdump_in_progress(void) } #ifdef CONFIG_KEXEC_FILE +#define ARCH_HAS_KIMAGE_ARCH + +struct kimage_arch { + phys_addr_t handover_buffer_addr; + unsigned long handover_buffer_size; +}; + int setup_purgatory(struct kimage *image, const void *slave_code, const void *fdt, unsigned long kernel_load_addr, unsigned long fdt_load_addr, unsigned long stack_top, int debug); -int setup_new_fdt(void *fdt, unsigned long initrd_load_addr, - unsigned long initrd_len, const char *cmdline); +int setup_new_fdt(const struct kimage *image, void *fdt, + unsigned long initrd_load_addr, unsigned long initrd_len, + const char *cmdline); bool find_debug_console(const void *fdt); #endif /* CONFIG_KEXEC_FILE */ diff --git a/arch/powerpc/kernel/kexec_elf_64.c b/arch/powerpc/kernel/kexec_elf_64.c index 3cc8ebce1a86..0c576e300384 100644 --- a/arch/powerpc/kernel/kexec_elf_64.c +++ b/arch/powerpc/kernel/kexec_elf_64.c @@ -208,7 +208,7 @@ void *elf64_load(struct kimage *image, char *kernel_buf, goto out; } - ret = setup_new_fdt(fdt, initrd_load_addr, initrd_len, cmdline); + ret = setup_new_fdt(image, fdt, initrd_load_addr, initrd_len, cmdline); if (ret) goto out; diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c index 3879b6d91c0b..d6077898200a 100644 --- a/arch/powerpc/kernel/machine_kexec_64.c +++ b/arch/powerpc/kernel/machine_kexec_64.c @@ -489,6 +489,77 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image) return image->fops->cleanup(image->image_loader_data); } +bool kexec_can_hand_over_buffer(void) +{ + return true; +} + +int arch_kexec_add_handover_buffer(struct kimage *image, + unsigned long load_addr, unsigned long size) +{ + image->arch.handover_buffer_addr = load_addr; + image->arch.handover_buffer_size = size; + + return 0; +} + +int kexec_get_handover_buffer(void **addr, unsigned long *size) +{ + int ret; + u64 start_addr, end_addr; + + ret = of_property_read_u64(of_chosen, + "linux,kexec-handover-buffer-start", + &start_addr); + if (ret == -EINVAL) + return -ENOENT; + else if (ret) + return -EINVAL; + + ret = of_property_read_u64(of_chosen, "linux,kexec-handover-buffer-end", + &end_addr); + if (ret == -EINVAL) + return -ENOENT; + else if (ret) + return -EINVAL; + + *addr = __va(start_addr); + /* -end is the first address after the buffer. */ + *size = end_addr - start_addr; + + return 0; +} + +int kexec_free_handover_buffer(void) +{ + int ret; + void *addr; + unsigned long size; + struct property *prop; + + ret = kexec_get_handover_buffer(&addr, &size); + if (ret) + return ret; + + ret = memblock_free(__pa(addr), size); + if (ret) + return ret; + + prop = of_find_property(of_chosen, "linux,kexec-handover-buffer-start", + NULL); + ret = of_remove_property(of_chosen, prop); + if (ret) + return ret; + + prop = of_find_property(of_chosen, "linux,kexec-handover-buffer-end", + NULL); + ret = of_remove_property(of_chosen, prop); + if (ret) + return ret; + + return 0; +} + /** * arch_kexec_walk_mem() - call func(data) for each unreserved memory block * @kbuf: Context info for the search. Also passed to @func. @@ -686,26 +757,16 @@ int setup_purgatory(struct kimage *image, const void *slave_code, return 0; } -/* - * setup_new_fdt() - modify /chosen and memory reservation for the next kernel - * @fdt: - * @initrd_load_addr: Address where the next initrd will be loaded. - * @initrd_len: Size of the next initrd, or 0 if there will be none. - * @cmdline: Command line for the next kernel, or NULL if there will - * be none. +/** + * delete_fdt_mem_rsv() - delete memory reservation with given address and size * * Return: 0 on success, or negative errno on error. */ -int setup_new_fdt(void *fdt, unsigned long initrd_load_addr, - unsigned long initrd_len, const char *cmdline) +static int delete_fdt_mem_rsv(void *fdt, uint64_t start, uint64_t size) { - uint64_t oldfdt_addr; - int i, ret, chosen_node; - const void *prop; + int i, ret, num_rsvs = fdt_num_mem_rsv(fdt); - /* Remove memory reservation for the current device tree. */ - oldfdt_addr = __pa(initial_boot_params); - for (i = 0; i < fdt_num_mem_rsv(fdt); i++) { + for (i = 0; i < num_rsvs; i++) { uint64_t rsv_start, rsv_size; ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size); @@ -714,19 +775,152 @@ int setup_new_fdt(void *fdt, unsigned long initrd_load_addr, return -EINVAL; } - if (rsv_start == oldfdt_addr && - rsv_size == fdt_totalsize(initial_boot_params)) { + if (rsv_start == start && rsv_size == size) { ret = fdt_del_mem_rsv(fdt, i); if (ret) { - pr_err("Error deleting fdt reservation.\n"); + pr_err("Error deleting device tree reservation.\n"); return -EINVAL; } - pr_debug("Removed old device tree reservation.\n"); - break; + return 0; } } + return -ENOENT; +} + +/** + * setup_handover_buffer() - add handover buffer information to the fdt + * @image: kexec image being loaded. + * @fdt: Flattened device tree for the next kernel. + * @chosen_node: Offset to the chosen node. + * + * Return: 0 on success, or negative errno on error. + */ +static int setup_handover_buffer(const struct kimage *image, void *fdt, + int chosen_node) +{ + int ret; + const void *prop; + + /* Did we receive a buffer from the previous kernel? */ + prop = fdt_getprop(fdt, chosen_node, + "linux,kexec-handover-buffer-start", NULL); + if (prop) { + u64 orig_start, orig_end; + unsigned long size; + void *addr; + + orig_start = fdt64_to_cpu(*((const fdt64_t *) prop)); + + prop = fdt_getprop(fdt, chosen_node, + "linux,kexec-handover-buffer-end", NULL); + if (!prop) { + pr_err("Malformed device tree.\n"); + return -EINVAL; + } + orig_end = fdt64_to_cpu(*((const fdt64_t *) prop)); + + /* Did we free the hand-over buffer from the previous kernel? */ + ret = kexec_get_handover_buffer(&addr, &size); + if (ret == -ENOENT) + addr = NULL; + else if (ret) + return ret; + + /* + * If we received a buffer from the previous kernel but deleted + * it from the live DT, or if we have a new buffer for the next + * kernel then we should remove the memory reservation from + * the FDT. + */ + if (addr == NULL || image->arch.handover_buffer_addr != 0) { + ret = delete_fdt_mem_rsv(fdt, orig_start, + orig_end - orig_start); + if (ret == 0) + pr_debug("Removed old hand-over buffer reservation.\n"); + else if (ret != -ENOENT) + return ret; + } + + /* + * If we received a buffer from the previous kernel but deleted + * it from the live DT and we have no buffer for the next kernel + * then we should remove the hand-over buffer properties from + * the FDT. + */ + if (addr == NULL && image->arch.handover_buffer_addr == 0) { + ret = fdt_delprop(fdt, chosen_node, + "linux,kexec-handover-buffer-start"); + if (ret) { + pr_err("Error setting up the new device tree.\n"); + return -EINVAL; + } + + ret = fdt_delprop(fdt, chosen_node, + "linux,kexec-handover-buffer-end"); + if (ret) { + pr_err("Error setting up the new device tree.\n"); + return -EINVAL; + } + } + } + + if (image->arch.handover_buffer_addr == 0) + return 0; + + ret = fdt_setprop_u64(fdt, chosen_node, + "linux,kexec-handover-buffer-start", + image->arch.handover_buffer_addr); + if (ret < 0) + return -EINVAL; + + /* -end is the first address after the buffer. */ + ret = fdt_setprop_u64(fdt, chosen_node, + "linux,kexec-handover-buffer-end", + image->arch.handover_buffer_addr + + image->arch.handover_buffer_size); + if (ret < 0) + return -EINVAL; + + ret = fdt_add_mem_rsv(fdt, image->arch.handover_buffer_addr, + image->arch.handover_buffer_size); + if (ret) + return -EINVAL; + + pr_debug("kexec handover buffer at 0x%llx, size = 0x%lx\n", + image->arch.handover_buffer_addr, + image->arch.handover_buffer_size); + + return 0; +} + +/** + * setup_new_fdt() - modify /chosen and memory reservations for the next kernel + * @image: kexec image being loaded. + * @fdt: Flattened device tree for the next kernel. + * @initrd_load_addr: Address where the next initrd will be loaded. + * @initrd_len: Size of the next initrd, or 0 if there will be none. + * @cmdline: Command line for the next kernel, or NULL if there will + * be none. + * + * Return: 0 on success, or negative errno on error. + */ +int setup_new_fdt(const struct kimage *image, void *fdt, + unsigned long initrd_load_addr, unsigned long initrd_len, + const char *cmdline) +{ + int ret, chosen_node; + const void *prop; + + /* Remove memory reservation for the current device tree. */ + ret = delete_fdt_mem_rsv(fdt, __pa(initial_boot_params), + fdt_totalsize(initial_boot_params)); + if (ret == 0) + pr_debug("Removed old device tree reservation.\n"); + else if (ret != -ENOENT) + return ret; + chosen_node = fdt_path_offset(fdt, "/chosen"); if (chosen_node == -FDT_ERR_NOTFOUND) { chosen_node = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"), @@ -743,7 +937,7 @@ int setup_new_fdt(void *fdt, unsigned long initrd_load_addr, /* Did we boot using an initrd? */ prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", NULL); if (prop) { - uint64_t tmp_start, tmp_end, tmp_size, tmp_sizepg; + uint64_t tmp_start, tmp_end, tmp_size; tmp_start = fdt64_to_cpu(*((const fdt64_t *) prop)); @@ -759,30 +953,14 @@ int setup_new_fdt(void *fdt, unsigned long initrd_load_addr, * reserve a multiple of PAGE_SIZE, so check for both. */ tmp_size = tmp_end - tmp_start; - tmp_sizepg = round_up(tmp_size, PAGE_SIZE); - - /* Remove memory reservation for the current initrd. */ - for (i = 0; i < fdt_num_mem_rsv(fdt); i++) { - uint64_t rsv_start, rsv_size; - - ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size); - if (ret) { - pr_err("Malformed device tree.\n"); - return -EINVAL; - } - - if (rsv_start == tmp_start && - (rsv_size == tmp_size || rsv_size == tmp_sizepg)) { - ret = fdt_del_mem_rsv(fdt, i); - if (ret) { - pr_err("Error deleting fdt reservation.\n"); - return -EINVAL; - } - pr_debug("Removed old initrd reservation.\n"); - - break; - } - } + ret = delete_fdt_mem_rsv(fdt, tmp_start, tmp_size); + if (ret == -ENOENT) + ret = delete_fdt_mem_rsv(fdt, tmp_start, + round_up(tmp_size, PAGE_SIZE)); + if (ret == 0) + pr_debug("Removed old initrd reservation.\n"); + else if (ret != -ENOENT) + return ret; /* If there's no new initrd, delete the old initrd's info. */ if (initrd_len == 0) { @@ -840,6 +1018,12 @@ int setup_new_fdt(void *fdt, unsigned long initrd_load_addr, } } + ret = setup_handover_buffer(image, fdt, chosen_node); + if (ret) { + pr_err("Error setting up the new device tree.\n"); + return ret; + } + ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0); if (ret) { pr_err("Error setting up the new device tree.\n");