From patchwork Fri Aug 23 19:49:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sven Schnelle X-Patchwork-Id: 1152426 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 46FYJR52F9z9sMr for ; Sat, 24 Aug 2019 06:43:19 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=stackframe.org Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=duncanthrax.net header.i=@duncanthrax.net header.b="qVd313TF"; dkim-atps=neutral Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46FYJQ61FZzDt65 for ; Sat, 24 Aug 2019 06:43:18 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=none (mailfrom) smtp.mailfrom=stackframe.org (client-ip=2001:470:70c5:1111::170; helo=smtp.duncanthrax.net; envelope-from=svens@stackframe.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=stackframe.org Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=duncanthrax.net header.i=@duncanthrax.net header.b="qVd313TF"; dkim-atps=neutral Received: from smtp.duncanthrax.net (smtp.duncanthrax.net [IPv6:2001:470:70c5:1111::170]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46FYCb2PHGzDqFG for ; Sat, 24 Aug 2019 06:39:05 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=duncanthrax.net; s=dkim; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From; bh=4ycuEiJW2KQk6v53YOEHwKrz1iP9SW/WQAEgMYW2YZ4=; b=qVd313TFfzbDY1YUzLFjvOaY1q tUyIM3JWkAj3nxWeNC45Abt1VvB0S8Hy08v0BRnO2gIYgCcCREAUvp80KZmOh3T2KCA5DiE1KNFNK 6RUSvCp1VqEDv8j9Y/vjGFgETc+9+8poepKwImVNatplOk10bAqTCXqKaEbtj2hsUQ6U=; Received: from [134.3.44.134] (helo=x280.stackframe.org) by smtp.eurescom.eu with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1i1FZ2-00071n-6M; Fri, 23 Aug 2019 21:49:36 +0200 From: Sven Schnelle To: kexec@lists.infradead.org Subject: [PATCH v5 1/7] kexec: add KEXEC_ELF Date: Fri, 23 Aug 2019 21:49:13 +0200 Message-Id: <20190823194919.30916-2-svens@stackframe.org> X-Mailer: git-send-email 2.23.0.rc1 In-Reply-To: <20190823194919.30916-1-svens@stackframe.org> References: <20190823194919.30916-1-svens@stackframe.org> MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sven Schnelle , Helge Deller , linuxppc-dev@lists.ozlabs.org, Thiago Jung Bauermann Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Right now powerpc provides an implementation to read elf files with the kexec_file_load() syscall. Make that available as a public kexec interface so it can be re-used on other architectures. Signed-off-by: Sven Schnelle --- arch/Kconfig | 3 + arch/powerpc/Kconfig | 1 + arch/powerpc/kernel/kexec_elf_64.c | 545 +----------------- include/linux/kexec.h | 24 + kernel/Makefile | 1 + .../kexec_elf_64.c => kernel/kexec_elf.c | 183 ++---- 6 files changed, 70 insertions(+), 687 deletions(-) copy arch/powerpc/kernel/kexec_elf_64.c => kernel/kexec_elf.c (75%) diff --git a/arch/Kconfig b/arch/Kconfig index a7b57dd42c26..01244412f393 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -18,6 +18,9 @@ config KEXEC_CORE select CRASH_CORE bool +config KEXEC_ELF + bool + config HAVE_IMA_KEXEC bool diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 7cb51bba4985..fbb0b305e1be 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -511,6 +511,7 @@ config KEXEC_FILE select KEXEC_CORE select HAVE_IMA_KEXEC select BUILD_BIN2C + select KEXEC_ELF depends on PPC64 depends on CRYPTO=y depends on CRYPTO_SHA256=y diff --git a/arch/powerpc/kernel/kexec_elf_64.c b/arch/powerpc/kernel/kexec_elf_64.c index 83cf7b852876..3072fd6dbe94 100644 --- a/arch/powerpc/kernel/kexec_elf_64.c +++ b/arch/powerpc/kernel/kexec_elf_64.c @@ -23,541 +23,6 @@ #include #include -#define PURGATORY_STACK_SIZE (16 * 1024) - -#define elf_addr_to_cpu elf64_to_cpu - -#ifndef Elf_Rel -#define Elf_Rel Elf64_Rel -#endif /* Elf_Rel */ - -struct elf_info { - /* - * Where the ELF binary contents are kept. - * Memory managed by the user of the struct. - */ - const char *buffer; - - const struct elfhdr *ehdr; - const struct elf_phdr *proghdrs; - struct elf_shdr *sechdrs; -}; - -static inline bool elf_is_elf_file(const struct elfhdr *ehdr) -{ - return memcmp(ehdr->e_ident, ELFMAG, SELFMAG) == 0; -} - -static uint64_t elf64_to_cpu(const struct elfhdr *ehdr, uint64_t value) -{ - if (ehdr->e_ident[EI_DATA] == ELFDATA2LSB) - value = le64_to_cpu(value); - else if (ehdr->e_ident[EI_DATA] == ELFDATA2MSB) - value = be64_to_cpu(value); - - return value; -} - -static uint16_t elf16_to_cpu(const struct elfhdr *ehdr, uint16_t value) -{ - if (ehdr->e_ident[EI_DATA] == ELFDATA2LSB) - value = le16_to_cpu(value); - else if (ehdr->e_ident[EI_DATA] == ELFDATA2MSB) - value = be16_to_cpu(value); - - return value; -} - -static uint32_t elf32_to_cpu(const struct elfhdr *ehdr, uint32_t value) -{ - if (ehdr->e_ident[EI_DATA] == ELFDATA2LSB) - value = le32_to_cpu(value); - else if (ehdr->e_ident[EI_DATA] == ELFDATA2MSB) - value = be32_to_cpu(value); - - return value; -} - -/** - * elf_is_ehdr_sane - check that it is safe to use the ELF header - * @buf_len: size of the buffer in which the ELF file is loaded. - */ -static bool elf_is_ehdr_sane(const struct elfhdr *ehdr, size_t buf_len) -{ - if (ehdr->e_phnum > 0 && ehdr->e_phentsize != sizeof(struct elf_phdr)) { - pr_debug("Bad program header size.\n"); - return false; - } else if (ehdr->e_shnum > 0 && - ehdr->e_shentsize != sizeof(struct elf_shdr)) { - pr_debug("Bad section header size.\n"); - return false; - } else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT || - ehdr->e_version != EV_CURRENT) { - pr_debug("Unknown ELF version.\n"); - return false; - } - - if (ehdr->e_phoff > 0 && ehdr->e_phnum > 0) { - size_t phdr_size; - - /* - * e_phnum is at most 65535 so calculating the size of the - * program header cannot overflow. - */ - phdr_size = sizeof(struct elf_phdr) * ehdr->e_phnum; - - /* Sanity check the program header table location. */ - if (ehdr->e_phoff + phdr_size < ehdr->e_phoff) { - pr_debug("Program headers at invalid location.\n"); - return false; - } else if (ehdr->e_phoff + phdr_size > buf_len) { - pr_debug("Program headers truncated.\n"); - return false; - } - } - - if (ehdr->e_shoff > 0 && ehdr->e_shnum > 0) { - size_t shdr_size; - - /* - * e_shnum is at most 65536 so calculating - * the size of the section header cannot overflow. - */ - shdr_size = sizeof(struct elf_shdr) * ehdr->e_shnum; - - /* Sanity check the section header table location. */ - if (ehdr->e_shoff + shdr_size < ehdr->e_shoff) { - pr_debug("Section headers at invalid location.\n"); - return false; - } else if (ehdr->e_shoff + shdr_size > buf_len) { - pr_debug("Section headers truncated.\n"); - return false; - } - } - - return true; -} - -static int elf_read_ehdr(const char *buf, size_t len, struct elfhdr *ehdr) -{ - struct elfhdr *buf_ehdr; - - if (len < sizeof(*buf_ehdr)) { - pr_debug("Buffer is too small to hold ELF header.\n"); - return -ENOEXEC; - } - - memset(ehdr, 0, sizeof(*ehdr)); - memcpy(ehdr->e_ident, buf, sizeof(ehdr->e_ident)); - if (!elf_is_elf_file(ehdr)) { - pr_debug("No ELF header magic.\n"); - return -ENOEXEC; - } - - if (ehdr->e_ident[EI_CLASS] != ELF_CLASS) { - pr_debug("Not a supported ELF class.\n"); - return -ENOEXEC; - } else if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB && - ehdr->e_ident[EI_DATA] != ELFDATA2MSB) { - pr_debug("Not a supported ELF data format.\n"); - return -ENOEXEC; - } - - buf_ehdr = (struct elfhdr *) buf; - if (elf16_to_cpu(ehdr, buf_ehdr->e_ehsize) != sizeof(*buf_ehdr)) { - pr_debug("Bad ELF header size.\n"); - return -ENOEXEC; - } - - ehdr->e_type = elf16_to_cpu(ehdr, buf_ehdr->e_type); - ehdr->e_machine = elf16_to_cpu(ehdr, buf_ehdr->e_machine); - ehdr->e_version = elf32_to_cpu(ehdr, buf_ehdr->e_version); - ehdr->e_entry = elf_addr_to_cpu(ehdr, buf_ehdr->e_entry); - ehdr->e_phoff = elf_addr_to_cpu(ehdr, buf_ehdr->e_phoff); - ehdr->e_shoff = elf_addr_to_cpu(ehdr, buf_ehdr->e_shoff); - ehdr->e_flags = elf32_to_cpu(ehdr, buf_ehdr->e_flags); - ehdr->e_phentsize = elf16_to_cpu(ehdr, buf_ehdr->e_phentsize); - ehdr->e_phnum = elf16_to_cpu(ehdr, buf_ehdr->e_phnum); - ehdr->e_shentsize = elf16_to_cpu(ehdr, buf_ehdr->e_shentsize); - ehdr->e_shnum = elf16_to_cpu(ehdr, buf_ehdr->e_shnum); - ehdr->e_shstrndx = elf16_to_cpu(ehdr, buf_ehdr->e_shstrndx); - - return elf_is_ehdr_sane(ehdr, len) ? 0 : -ENOEXEC; -} - -/** - * elf_is_phdr_sane - check that it is safe to use the program header - * @buf_len: size of the buffer in which the ELF file is loaded. - */ -static bool elf_is_phdr_sane(const struct elf_phdr *phdr, size_t buf_len) -{ - - if (phdr->p_offset + phdr->p_filesz < phdr->p_offset) { - pr_debug("ELF segment location wraps around.\n"); - return false; - } else if (phdr->p_offset + phdr->p_filesz > buf_len) { - pr_debug("ELF segment not in file.\n"); - return false; - } else if (phdr->p_paddr + phdr->p_memsz < phdr->p_paddr) { - pr_debug("ELF segment address wraps around.\n"); - return false; - } - - return true; -} - -static int elf_read_phdr(const char *buf, size_t len, struct elf_info *elf_info, - int idx) -{ - /* Override the const in proghdrs, we are the ones doing the loading. */ - struct elf_phdr *phdr = (struct elf_phdr *) &elf_info->proghdrs[idx]; - const char *pbuf; - struct elf_phdr *buf_phdr; - - pbuf = buf + elf_info->ehdr->e_phoff + (idx * sizeof(*buf_phdr)); - buf_phdr = (struct elf_phdr *) pbuf; - - phdr->p_type = elf32_to_cpu(elf_info->ehdr, buf_phdr->p_type); - phdr->p_offset = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_offset); - phdr->p_paddr = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_paddr); - phdr->p_vaddr = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_vaddr); - phdr->p_flags = elf32_to_cpu(elf_info->ehdr, buf_phdr->p_flags); - - /* - * The following fields have a type equivalent to Elf_Addr - * both in 32 bit and 64 bit ELF. - */ - phdr->p_filesz = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_filesz); - phdr->p_memsz = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_memsz); - phdr->p_align = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_align); - - return elf_is_phdr_sane(phdr, len) ? 0 : -ENOEXEC; -} - -/** - * elf_read_phdrs - read the program headers from the buffer - * - * This function assumes that the program header table was checked for sanity. - * Use elf_is_ehdr_sane() if it wasn't. - */ -static int elf_read_phdrs(const char *buf, size_t len, - struct elf_info *elf_info) -{ - size_t phdr_size, i; - const struct elfhdr *ehdr = elf_info->ehdr; - - /* - * e_phnum is at most 65535 so calculating the size of the - * program header cannot overflow. - */ - phdr_size = sizeof(struct elf_phdr) * ehdr->e_phnum; - - elf_info->proghdrs = kzalloc(phdr_size, GFP_KERNEL); - if (!elf_info->proghdrs) - return -ENOMEM; - - for (i = 0; i < ehdr->e_phnum; i++) { - int ret; - - ret = elf_read_phdr(buf, len, elf_info, i); - if (ret) { - kfree(elf_info->proghdrs); - elf_info->proghdrs = NULL; - return ret; - } - } - - return 0; -} - -/** - * elf_is_shdr_sane - check that it is safe to use the section header - * @buf_len: size of the buffer in which the ELF file is loaded. - */ -static bool elf_is_shdr_sane(const struct elf_shdr *shdr, size_t buf_len) -{ - bool size_ok; - - /* SHT_NULL headers have undefined values, so we can't check them. */ - if (shdr->sh_type == SHT_NULL) - return true; - - /* Now verify sh_entsize */ - switch (shdr->sh_type) { - case SHT_SYMTAB: - size_ok = shdr->sh_entsize == sizeof(Elf_Sym); - break; - case SHT_RELA: - size_ok = shdr->sh_entsize == sizeof(Elf_Rela); - break; - case SHT_DYNAMIC: - size_ok = shdr->sh_entsize == sizeof(Elf_Dyn); - break; - case SHT_REL: - size_ok = shdr->sh_entsize == sizeof(Elf_Rel); - break; - case SHT_NOTE: - case SHT_PROGBITS: - case SHT_HASH: - case SHT_NOBITS: - default: - /* - * This is a section whose entsize requirements - * I don't care about. If I don't know about - * the section I can't care about it's entsize - * requirements. - */ - size_ok = true; - break; - } - - if (!size_ok) { - pr_debug("ELF section with wrong entry size.\n"); - return false; - } else if (shdr->sh_addr + shdr->sh_size < shdr->sh_addr) { - pr_debug("ELF section address wraps around.\n"); - return false; - } - - if (shdr->sh_type != SHT_NOBITS) { - if (shdr->sh_offset + shdr->sh_size < shdr->sh_offset) { - pr_debug("ELF section location wraps around.\n"); - return false; - } else if (shdr->sh_offset + shdr->sh_size > buf_len) { - pr_debug("ELF section not in file.\n"); - return false; - } - } - - return true; -} - -static int elf_read_shdr(const char *buf, size_t len, struct elf_info *elf_info, - int idx) -{ - struct elf_shdr *shdr = &elf_info->sechdrs[idx]; - const struct elfhdr *ehdr = elf_info->ehdr; - const char *sbuf; - struct elf_shdr *buf_shdr; - - sbuf = buf + ehdr->e_shoff + idx * sizeof(*buf_shdr); - buf_shdr = (struct elf_shdr *) sbuf; - - shdr->sh_name = elf32_to_cpu(ehdr, buf_shdr->sh_name); - shdr->sh_type = elf32_to_cpu(ehdr, buf_shdr->sh_type); - shdr->sh_addr = elf_addr_to_cpu(ehdr, buf_shdr->sh_addr); - shdr->sh_offset = elf_addr_to_cpu(ehdr, buf_shdr->sh_offset); - shdr->sh_link = elf32_to_cpu(ehdr, buf_shdr->sh_link); - shdr->sh_info = elf32_to_cpu(ehdr, buf_shdr->sh_info); - - /* - * The following fields have a type equivalent to Elf_Addr - * both in 32 bit and 64 bit ELF. - */ - shdr->sh_flags = elf_addr_to_cpu(ehdr, buf_shdr->sh_flags); - shdr->sh_size = elf_addr_to_cpu(ehdr, buf_shdr->sh_size); - shdr->sh_addralign = elf_addr_to_cpu(ehdr, buf_shdr->sh_addralign); - shdr->sh_entsize = elf_addr_to_cpu(ehdr, buf_shdr->sh_entsize); - - return elf_is_shdr_sane(shdr, len) ? 0 : -ENOEXEC; -} - -/** - * elf_read_shdrs - read the section headers from the buffer - * - * This function assumes that the section header table was checked for sanity. - * Use elf_is_ehdr_sane() if it wasn't. - */ -static int elf_read_shdrs(const char *buf, size_t len, - struct elf_info *elf_info) -{ - size_t shdr_size, i; - - /* - * e_shnum is at most 65536 so calculating - * the size of the section header cannot overflow. - */ - shdr_size = sizeof(struct elf_shdr) * elf_info->ehdr->e_shnum; - - elf_info->sechdrs = kzalloc(shdr_size, GFP_KERNEL); - if (!elf_info->sechdrs) - return -ENOMEM; - - for (i = 0; i < elf_info->ehdr->e_shnum; i++) { - int ret; - - ret = elf_read_shdr(buf, len, elf_info, i); - if (ret) { - kfree(elf_info->sechdrs); - elf_info->sechdrs = NULL; - return ret; - } - } - - return 0; -} - -/** - * elf_read_from_buffer - read ELF file and sets up ELF header and ELF info - * @buf: Buffer to read ELF file from. - * @len: Size of @buf. - * @ehdr: Pointer to existing struct which will be populated. - * @elf_info: Pointer to existing struct which will be populated. - * - * This function allows reading ELF files with different byte order than - * the kernel, byte-swapping the fields as needed. - * - * Return: - * On success returns 0, and the caller should call elf_free_info(elf_info) to - * free the memory allocated for the section and program headers. - */ -int elf_read_from_buffer(const char *buf, size_t len, struct elfhdr *ehdr, - struct elf_info *elf_info) -{ - int ret; - - ret = elf_read_ehdr(buf, len, ehdr); - if (ret) - return ret; - - elf_info->buffer = buf; - elf_info->ehdr = ehdr; - if (ehdr->e_phoff > 0 && ehdr->e_phnum > 0) { - ret = elf_read_phdrs(buf, len, elf_info); - if (ret) - return ret; - } - if (ehdr->e_shoff > 0 && ehdr->e_shnum > 0) { - ret = elf_read_shdrs(buf, len, elf_info); - if (ret) { - kfree(elf_info->proghdrs); - return ret; - } - } - - return 0; -} - -/** - * elf_free_info - free memory allocated by elf_read_from_buffer - */ -void elf_free_info(struct elf_info *elf_info) -{ - kfree(elf_info->proghdrs); - kfree(elf_info->sechdrs); - memset(elf_info, 0, sizeof(*elf_info)); -} -/** - * build_elf_exec_info - read ELF executable and check that we can use it - */ -static int build_elf_exec_info(const char *buf, size_t len, struct elfhdr *ehdr, - struct elf_info *elf_info) -{ - int i; - int ret; - - ret = elf_read_from_buffer(buf, len, ehdr, elf_info); - if (ret) - return ret; - - /* Big endian vmlinux has type ET_DYN. */ - if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) { - pr_err("Not an ELF executable.\n"); - goto error; - } else if (!elf_info->proghdrs) { - pr_err("No ELF program header.\n"); - goto error; - } - - for (i = 0; i < ehdr->e_phnum; i++) { - /* - * Kexec does not support loading interpreters. - * In addition this check keeps us from attempting - * to kexec ordinay executables. - */ - if (elf_info->proghdrs[i].p_type == PT_INTERP) { - pr_err("Requires an ELF interpreter.\n"); - goto error; - } - } - - return 0; -error: - elf_free_info(elf_info); - return -ENOEXEC; -} - -static int elf64_probe(const char *buf, unsigned long len) -{ - struct elfhdr ehdr; - struct elf_info elf_info; - int ret; - - ret = build_elf_exec_info(buf, len, &ehdr, &elf_info); - if (ret) - return ret; - - elf_free_info(&elf_info); - - return elf_check_arch(&ehdr) ? 0 : -ENOEXEC; -} - -/** - * elf_exec_load - load ELF executable image - * @lowest_load_addr: On return, will be the address where the first PT_LOAD - * section will be loaded in memory. - * - * Return: - * 0 on success, negative value on failure. - */ -static int elf_exec_load(struct kimage *image, struct elfhdr *ehdr, - struct elf_info *elf_info, - unsigned long *lowest_load_addr) -{ - unsigned long base = 0, lowest_addr = UINT_MAX; - int ret; - size_t i; - struct kexec_buf kbuf = { .image = image, .buf_max = ppc64_rma_size, - .top_down = false }; - - /* Read in the PT_LOAD segments. */ - for (i = 0; i < ehdr->e_phnum; i++) { - unsigned long load_addr; - size_t size; - const struct elf_phdr *phdr; - - phdr = &elf_info->proghdrs[i]; - if (phdr->p_type != PT_LOAD) - continue; - - size = phdr->p_filesz; - if (size > phdr->p_memsz) - size = phdr->p_memsz; - - kbuf.buffer = (void *) elf_info->buffer + phdr->p_offset; - kbuf.bufsz = size; - kbuf.memsz = phdr->p_memsz; - kbuf.buf_align = phdr->p_align; - kbuf.buf_min = phdr->p_paddr + base; - kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; - ret = kexec_add_buffer(&kbuf); - if (ret) - goto out; - load_addr = kbuf.mem; - - if (load_addr < lowest_addr) - lowest_addr = load_addr; - } - - /* Update entry point to reflect new load address. */ - ehdr->e_entry += base; - - *lowest_load_addr = lowest_addr; - ret = 0; - out: - return ret; -} - static void *elf64_load(struct kimage *image, char *kernel_buf, unsigned long kernel_len, char *initrd, unsigned long initrd_len, char *cmdline, @@ -570,18 +35,18 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, void *fdt; const void *slave_code; struct elfhdr ehdr; - struct elf_info elf_info; + struct kexec_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, .mem = KEXEC_BUF_MEM_UNKNOWN }; - ret = build_elf_exec_info(kernel_buf, kernel_len, &ehdr, &elf_info); + ret = kexec_build_elf_info(kernel_buf, kernel_len, &ehdr, &elf_info); if (ret) goto out; - ret = elf_exec_load(image, &ehdr, &elf_info, &kernel_load_addr); + ret = kexec_elf_load(image, &ehdr, &elf_info, &kbuf, &kernel_load_addr); if (ret) goto out; @@ -648,13 +113,13 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, pr_err("Error setting up the purgatory.\n"); out: - elf_free_info(&elf_info); + kexec_free_elf_info(&elf_info); /* Make kimage_file_post_load_cleanup free the fdt buffer for us. */ return ret ? ERR_PTR(ret) : fdt; } const struct kexec_file_ops kexec_elf64_ops = { - .probe = elf64_probe, + .probe = kexec_elf_probe, .load = elf64_load, }; diff --git a/include/linux/kexec.h b/include/linux/kexec.h index b9b1bc5f9669..da2a6b1d69e7 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -216,6 +216,30 @@ extern int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map, void **addr, unsigned long *sz); #endif /* CONFIG_KEXEC_FILE */ +#ifdef CONFIG_KEXEC_ELF +struct kexec_elf_info { + /* + * Where the ELF binary contents are kept. + * Memory managed by the user of the struct. + */ + const char *buffer; + + const struct elfhdr *ehdr; + const struct elf_phdr *proghdrs; + struct elf_shdr *sechdrs; +}; + +int kexec_build_elf_info(const char *buf, size_t len, struct elfhdr *ehdr, + struct kexec_elf_info *elf_info); + +int kexec_elf_load(struct kimage *image, struct elfhdr *ehdr, + struct kexec_elf_info *elf_info, + struct kexec_buf *kbuf, + unsigned long *lowest_load_addr); + +void kexec_free_elf_info(struct kexec_elf_info *elf_info); +int kexec_elf_probe(const char *buf, unsigned long len); +#endif struct kimage { kimage_entry_t head; kimage_entry_t *entry; diff --git a/kernel/Makefile b/kernel/Makefile index ef0d95a190b4..48c5376d290a 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -64,6 +64,7 @@ obj-$(CONFIG_CRASH_CORE) += crash_core.o obj-$(CONFIG_KEXEC_CORE) += kexec_core.o obj-$(CONFIG_KEXEC) += kexec.o obj-$(CONFIG_KEXEC_FILE) += kexec_file.o +obj-$(CONFIG_KEXEC_ELF) += kexec_elf.o obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o obj-$(CONFIG_COMPAT) += compat.o obj-$(CONFIG_CGROUPS) += cgroup/ diff --git a/arch/powerpc/kernel/kexec_elf_64.c b/kernel/kexec_elf.c similarity index 75% copy from arch/powerpc/kernel/kexec_elf_64.c copy to kernel/kexec_elf.c index 83cf7b852876..26c6310167a0 100644 --- a/arch/powerpc/kernel/kexec_elf_64.c +++ b/kernel/kexec_elf.c @@ -17,9 +17,7 @@ #include #include -#include #include -#include #include #include @@ -31,21 +29,9 @@ #define Elf_Rel Elf64_Rel #endif /* Elf_Rel */ -struct elf_info { - /* - * Where the ELF binary contents are kept. - * Memory managed by the user of the struct. - */ - const char *buffer; - - const struct elfhdr *ehdr; - const struct elf_phdr *proghdrs; - struct elf_shdr *sechdrs; -}; - static inline bool elf_is_elf_file(const struct elfhdr *ehdr) { - return memcmp(ehdr->e_ident, ELFMAG, SELFMAG) == 0; + return memcmp(ehdr->e_ident, ELFMAG, SELFMAG) == 0; } static uint64_t elf64_to_cpu(const struct elfhdr *ehdr, uint64_t value) @@ -206,7 +192,8 @@ static bool elf_is_phdr_sane(const struct elf_phdr *phdr, size_t buf_len) return true; } -static int elf_read_phdr(const char *buf, size_t len, struct elf_info *elf_info, +static int elf_read_phdr(const char *buf, size_t len, + struct kexec_elf_info *elf_info, int idx) { /* Override the const in proghdrs, we are the ones doing the loading. */ @@ -241,7 +228,7 @@ static int elf_read_phdr(const char *buf, size_t len, struct elf_info *elf_info, * Use elf_is_ehdr_sane() if it wasn't. */ static int elf_read_phdrs(const char *buf, size_t len, - struct elf_info *elf_info) + struct kexec_elf_info *elf_info) { size_t phdr_size, i; const struct elfhdr *ehdr = elf_info->ehdr; @@ -332,7 +319,8 @@ static bool elf_is_shdr_sane(const struct elf_shdr *shdr, size_t buf_len) return true; } -static int elf_read_shdr(const char *buf, size_t len, struct elf_info *elf_info, +static int elf_read_shdr(const char *buf, size_t len, + struct kexec_elf_info *elf_info, int idx) { struct elf_shdr *shdr = &elf_info->sechdrs[idx]; @@ -369,7 +357,7 @@ static int elf_read_shdr(const char *buf, size_t len, struct elf_info *elf_info, * Use elf_is_ehdr_sane() if it wasn't. */ static int elf_read_shdrs(const char *buf, size_t len, - struct elf_info *elf_info) + struct kexec_elf_info *elf_info) { size_t shdr_size, i; @@ -408,11 +396,13 @@ static int elf_read_shdrs(const char *buf, size_t len, * the kernel, byte-swapping the fields as needed. * * Return: - * On success returns 0, and the caller should call elf_free_info(elf_info) to - * free the memory allocated for the section and program headers. + * On success returns 0, and the caller should call + * kexec_free_elf_info(elf_info) to free the memory allocated for the section + * and program headers. */ -int elf_read_from_buffer(const char *buf, size_t len, struct elfhdr *ehdr, - struct elf_info *elf_info) +static int elf_read_from_buffer(const char *buf, size_t len, + struct elfhdr *ehdr, + struct kexec_elf_info *elf_info) { int ret; @@ -439,19 +429,19 @@ int elf_read_from_buffer(const char *buf, size_t len, struct elfhdr *ehdr, } /** - * elf_free_info - free memory allocated by elf_read_from_buffer + * kexec_free_elf_info - free memory allocated by elf_read_from_buffer */ -void elf_free_info(struct elf_info *elf_info) +void kexec_free_elf_info(struct kexec_elf_info *elf_info) { kfree(elf_info->proghdrs); kfree(elf_info->sechdrs); memset(elf_info, 0, sizeof(*elf_info)); } /** - * build_elf_exec_info - read ELF executable and check that we can use it + * kexec_build_elf_info - read ELF executable and check that we can use it */ -static int build_elf_exec_info(const char *buf, size_t len, struct elfhdr *ehdr, - struct elf_info *elf_info) +int kexec_build_elf_info(const char *buf, size_t len, struct elfhdr *ehdr, + struct kexec_elf_info *elf_info) { int i; int ret; @@ -483,42 +473,42 @@ static int build_elf_exec_info(const char *buf, size_t len, struct elfhdr *ehdr, return 0; error: - elf_free_info(elf_info); + kexec_free_elf_info(elf_info); return -ENOEXEC; } -static int elf64_probe(const char *buf, unsigned long len) + +int kexec_elf_probe(const char *buf, unsigned long len) { struct elfhdr ehdr; - struct elf_info elf_info; + struct kexec_elf_info elf_info; int ret; - ret = build_elf_exec_info(buf, len, &ehdr, &elf_info); + ret = kexec_build_elf_info(buf, len, &ehdr, &elf_info); if (ret) return ret; - elf_free_info(&elf_info); + kexec_free_elf_info(&elf_info); return elf_check_arch(&ehdr) ? 0 : -ENOEXEC; } /** - * elf_exec_load - load ELF executable image + * kexec_elf_load - load ELF executable image * @lowest_load_addr: On return, will be the address where the first PT_LOAD * section will be loaded in memory. * * Return: * 0 on success, negative value on failure. */ -static int elf_exec_load(struct kimage *image, struct elfhdr *ehdr, - struct elf_info *elf_info, +int kexec_elf_load(struct kimage *image, struct elfhdr *ehdr, + struct kexec_elf_info *elf_info, + struct kexec_buf *kbuf, unsigned long *lowest_load_addr) { unsigned long base = 0, lowest_addr = UINT_MAX; int ret; size_t i; - struct kexec_buf kbuf = { .image = image, .buf_max = ppc64_rma_size, - .top_down = false }; /* Read in the PT_LOAD segments. */ for (i = 0; i < ehdr->e_phnum; i++) { @@ -534,16 +524,16 @@ static int elf_exec_load(struct kimage *image, struct elfhdr *ehdr, if (size > phdr->p_memsz) size = phdr->p_memsz; - kbuf.buffer = (void *) elf_info->buffer + phdr->p_offset; - kbuf.bufsz = size; - kbuf.memsz = phdr->p_memsz; - kbuf.buf_align = phdr->p_align; - kbuf.buf_min = phdr->p_paddr + base; - kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; - ret = kexec_add_buffer(&kbuf); + kbuf->buffer = (void *) elf_info->buffer + phdr->p_offset; + kbuf->bufsz = size; + kbuf->memsz = phdr->p_memsz; + kbuf->buf_align = phdr->p_align; + kbuf->buf_min = phdr->p_paddr + base; + kbuf->mem = KEXEC_BUF_MEM_UNKNOWN; + ret = kexec_add_buffer(kbuf); if (ret) goto out; - load_addr = kbuf.mem; + load_addr = kbuf->mem; if (load_addr < lowest_addr) lowest_addr = load_addr; @@ -557,104 +547,3 @@ static int elf_exec_load(struct kimage *image, struct elfhdr *ehdr, out: return ret; } - -static void *elf64_load(struct kimage *image, char *kernel_buf, - unsigned long kernel_len, char *initrd, - unsigned long initrd_len, char *cmdline, - unsigned long cmdline_len) -{ - int ret; - unsigned int fdt_size; - unsigned long kernel_load_addr; - unsigned long initrd_load_addr = 0, fdt_load_addr; - void *fdt; - const void *slave_code; - struct elfhdr ehdr; - 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, - .mem = KEXEC_BUF_MEM_UNKNOWN }; - - ret = build_elf_exec_info(kernel_buf, kernel_len, &ehdr, &elf_info); - if (ret) - goto out; - - ret = elf_exec_load(image, &ehdr, &elf_info, &kernel_load_addr); - if (ret) - goto out; - - pr_debug("Loaded the kernel at 0x%lx\n", kernel_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", pbuf.mem); - - if (initrd != NULL) { - kbuf.buffer = initrd; - kbuf.bufsz = kbuf.memsz = initrd_len; - kbuf.buf_align = PAGE_SIZE; - kbuf.top_down = false; - kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; - ret = kexec_add_buffer(&kbuf); - if (ret) - goto out; - initrd_load_addr = kbuf.mem; - - pr_debug("Loaded initrd at 0x%lx\n", initrd_load_addr); - } - - fdt_size = fdt_totalsize(initial_boot_params) * 2; - fdt = kmalloc(fdt_size, GFP_KERNEL); - if (!fdt) { - pr_err("Not enough memory for the device tree.\n"); - ret = -ENOMEM; - goto out; - } - ret = fdt_open_into(initial_boot_params, fdt, fdt_size); - if (ret < 0) { - pr_err("Error setting up the new device tree.\n"); - ret = -EINVAL; - goto out; - } - - ret = setup_new_fdt(image, fdt, initrd_load_addr, initrd_len, cmdline); - if (ret) - goto out; - - fdt_pack(fdt); - - kbuf.buffer = fdt; - kbuf.bufsz = kbuf.memsz = fdt_size; - kbuf.buf_align = PAGE_SIZE; - kbuf.top_down = true; - kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; - ret = kexec_add_buffer(&kbuf); - if (ret) - goto out; - fdt_load_addr = kbuf.mem; - - pr_debug("Loaded device tree at 0x%lx\n", fdt_load_addr); - - slave_code = elf_info.buffer + elf_info.proghdrs[0].p_offset; - ret = setup_purgatory(image, slave_code, fdt, kernel_load_addr, - fdt_load_addr); - if (ret) - pr_err("Error setting up the purgatory.\n"); - -out: - elf_free_info(&elf_info); - - /* Make kimage_file_post_load_cleanup free the fdt buffer for us. */ - return ret ? ERR_PTR(ret) : fdt; -} - -const struct kexec_file_ops kexec_elf64_ops = { - .probe = elf64_probe, - .load = elf64_load, -};