From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751849AbeBZQIp (ORCPT ); Mon, 26 Feb 2018 11:08:45 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:34174 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751707AbeBZQIo (ORCPT ); Mon, 26 Feb 2018 11:08:44 -0500 From: Philipp Rudo To: kexec@lists.infradead.org, linux-s390@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Eric Biederman , Vivek Goyal , Michael Ellerman , Thiago Jung Bauermann , Martin Schwidefsky , Heiko Carstens , Andrew Morton , x86@kernel.org, Dave Young , AKASHI Takahiro Subject: [PATCH 10/11] kexec_file: Allow archs to set purgatory load address Date: Mon, 26 Feb 2018 16:16:19 +0100 X-Mailer: git-send-email 2.13.5 In-Reply-To: <20180226151620.20970-1-prudo@linux.vnet.ibm.com> References: <20180226151620.20970-1-prudo@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18022615-0040-0000-0000-00000438008C X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18022615-0041-0000-0000-000020DA2865 Message-Id: <20180226151620.20970-11-prudo@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-02-26_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1802260202 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For s390 new kernels are loaded to fixed addresses in memory before they are booted. With the current code this is a problem as it assumes the kernel will be loaded to an 'arbitrary' address. In particular, kexec_locate_mem_hole searches for a large enough memory region and sets the load address (kexec_bufer->mem) to it. Luckily there is a simple workaround for this problem. By returning 1 in arch_kexec_walk_mem, kexec_locate_mem_hole is turned off. This allows the architecture to set kbuf->mem by hand. While the trick works fine for the kernel it does not for the purgatory as here the architectures don't have access to its kexec_buffer. Give architectures access to the purgatories kexec_buffer by changing kexec_load_purgatory to take a pointer to it. With this change architectures have access to the buffer and can edit it as they need. A nice side effect of this change is that we can get rid of the purgatory_info->purgatory_load_address field. As now the information stored there can directly be accessed from kbuf->mem. Signed-off-by: Philipp Rudo Reviewed-by: Martin Schwidefsky --- arch/powerpc/kernel/kexec_elf_64.c | 9 +++++---- arch/x86/kernel/kexec-bzimage64.c | 8 ++++---- include/linux/kexec.h | 7 +------ kernel/kexec_file.c | 29 ++++++++++++++++------------- 4 files changed, 26 insertions(+), 27 deletions(-) diff --git a/arch/powerpc/kernel/kexec_elf_64.c b/arch/powerpc/kernel/kexec_elf_64.c index 9a42309b091a..82448c03502d 100644 --- a/arch/powerpc/kernel/kexec_elf_64.c +++ b/arch/powerpc/kernel/kexec_elf_64.c @@ -572,7 +572,7 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, { int ret; unsigned int fdt_size; - unsigned long kernel_load_addr, purgatory_load_addr; + unsigned long kernel_load_addr; unsigned long initrd_load_addr = 0, fdt_load_addr; void *fdt; const void *slave_code; @@ -580,6 +580,8 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, struct elf_info elf_info; struct kexec_buf kbuf = { .image = image, .buf_min = 0, .buf_max = ppc64_rma_size }; + struct kexec_buf pbuf = { .image = image, .buf_min = 0, + .buf_max = ppc64_rma_size, .top_down = true }; ret = build_elf_exec_info(kernel_buf, kernel_len, &ehdr, &elf_info); if (ret) @@ -591,14 +593,13 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, pr_debug("Loaded the kernel at 0x%lx\n", kernel_load_addr); - ret = kexec_load_purgatory(image, 0, ppc64_rma_size, true, - &purgatory_load_addr); + ret = kexec_load_purgatory(image, &pbuf); if (ret) { pr_err("Loading purgatory failed.\n"); goto out; } - pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr); + pr_debug("Loaded purgatory at 0x%lx\n", pbuf.mem); if (initrd != NULL) { kbuf.buffer = initrd; diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c index fb095ba0c02f..df183585928f 100644 --- a/arch/x86/kernel/kexec-bzimage64.c +++ b/arch/x86/kernel/kexec-bzimage64.c @@ -334,7 +334,6 @@ static void *bzImage64_load(struct kimage *image, char *kernel, unsigned long setup_header_size, params_cmdline_sz; struct boot_params *params; unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr; - unsigned long purgatory_load_addr; struct bzimage64_data *ldata; struct kexec_entry64_regs regs64; void *stack; @@ -342,6 +341,8 @@ static void *bzImage64_load(struct kimage *image, char *kernel, unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset; struct kexec_buf kbuf = { .image = image, .buf_max = ULONG_MAX, .top_down = true }; + struct kexec_buf pbuf = { .image = image, .buf_min = MIN_PURGATORY_ADDR, + .buf_max = ULONG_MAX, .top_down = true }; header = (struct setup_header *)(kernel + setup_hdr_offset); setup_sects = header->setup_sects; @@ -379,14 +380,13 @@ static void *bzImage64_load(struct kimage *image, char *kernel, * Load purgatory. For 64bit entry point, purgatory code can be * anywhere. */ - ret = kexec_load_purgatory(image, MIN_PURGATORY_ADDR, ULONG_MAX, 1, - &purgatory_load_addr); + ret = kexec_load_purgatory(image, &pbuf); if (ret) { pr_err("Loading purgatory failed\n"); return ERR_PTR(ret); } - pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr); + pr_debug("Loaded purgatory at 0x%lx\n", pbuf.mem); /* diff --git a/include/linux/kexec.h b/include/linux/kexec.h index f15446be0e25..1cd9c5f49859 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -114,9 +114,6 @@ struct purgatory_info { * relocation. This memory can be freed post image load. */ void *purgatory_buf; - - /* Address where purgatory is finally loaded and is executed from */ - unsigned long purgatory_load_addr; }; struct kimage; @@ -237,9 +234,7 @@ extern asmlinkage long sys_kexec_load(unsigned long entry, extern int kernel_kexec(void); extern struct page *kimage_alloc_control_pages(struct kimage *image, unsigned int order); -extern int kexec_load_purgatory(struct kimage *image, unsigned long min, - unsigned long max, int top_down, - unsigned long *load_addr); +extern int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf); extern int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name, void *buf, unsigned int size, bool get_value); diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 25b44d1a664a..d69d1bf9e7a2 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -669,8 +669,8 @@ static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi, int i, ret; sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff; - bss_align = 1; - bss_sz = 0; + kbuf->buf_align = bss_align = 1; + kbuf->bufsz = bss_sz = 0; for (i = 0; i < pi->ehdr->e_shnum; i++) { if (!(sechdrs[i].sh_flags & SHF_ALLOC)) @@ -702,7 +702,6 @@ static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi, ret = kexec_add_buffer(kbuf); if (ret) goto out; - pi->purgatory_load_addr = kbuf->mem; return 0; out: @@ -836,27 +835,32 @@ static int kexec_apply_relocations(struct kimage *image) return 0; } -/* Load relocatable purgatory object and relocate it appropriately */ -int kexec_load_purgatory(struct kimage *image, unsigned long min, - unsigned long max, int top_down, - unsigned long *load_addr) +/* + * kexec_load_purgatory - Load and relocate the purgatory object. + * @image: Image to add the purgatory to. + * @kbuf: Memory parameters to use. + * + * Allocates the memory needed for image->purgatory_info.sechdrs and + * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible + * to free the memory after use. + * + * Return: 0 on success, negative errno on error. + */ +int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf) { struct purgatory_info *pi = &image->purgatory_info; int ret; - struct kexec_buf kbuf = { .image = image, .bufsz = 0, .buf_align = 1, - .buf_min = min, .buf_max = max, - .top_down = top_down }; if (kexec_purgatory_size <= 0) return -EINVAL; pi->ehdr = (const Elf_Ehdr *)kexec_purgatory; - ret = kexec_purgatory_setup_kbuf(pi, &kbuf); + ret = kexec_purgatory_setup_kbuf(pi, kbuf); if (ret) return ret; - ret = kexec_purgatory_setup_sechdrs(pi, &kbuf); + ret = kexec_purgatory_setup_sechdrs(pi, kbuf); if (ret) goto out_free_kbuf; @@ -864,7 +868,6 @@ int kexec_load_purgatory(struct kimage *image, unsigned long min, if (ret) goto out; - *load_addr = pi->purgatory_load_addr; return 0; out: vfree(pi->sechdrs); -- 2.13.5