From 9ec4ecef0af7790551109283ca039a7c52de343c Mon Sep 17 00:00:00 2001 From: AKASHI Takahiro Date: Fri, 13 Apr 2018 15:35:49 -0700 Subject: kexec_file,x86,powerpc: factor out kexec_file_ops functions As arch_kexec_kernel_image_{probe,load}(), arch_kimage_file_post_load_cleanup() and arch_kexec_kernel_verify_sig() are almost duplicated among architectures, they can be commonalized with an architecture-defined kexec_file_ops array. So let's factor them out. Link: http://lkml.kernel.org/r/20180306102303.9063-3-takahiro.akashi@linaro.org Signed-off-by: AKASHI Takahiro Acked-by: Dave Young Tested-by: Dave Young Cc: Vivek Goyal Cc: Baoquan He Cc: Michael Ellerman Cc: Thiago Jung Bauermann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kexec.h | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'include') diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 0ebcbeb21056..102c725421a1 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -135,6 +135,11 @@ struct kexec_file_ops { #endif }; +extern const struct kexec_file_ops * const kexec_file_loaders[]; + +int kexec_image_probe_default(struct kimage *image, void *buf, + unsigned long buf_len); + /** * struct kexec_buf - parameters for finding a place for a buffer in memory * @image: kexec image in which memory to search. @@ -209,7 +214,7 @@ struct kimage { unsigned long cmdline_buf_len; /* File operations provided by image loader */ - struct kexec_file_ops *fops; + const struct kexec_file_ops *fops; /* Image loader handling the kernel can store a pointer here */ void *image_loader_data; @@ -273,12 +278,6 @@ int crash_shrink_memory(unsigned long new_size); size_t crash_get_memory_size(void); void crash_free_reserved_phys_range(unsigned long begin, unsigned long end); -int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf, - unsigned long buf_len); -void * __weak arch_kexec_kernel_image_load(struct kimage *image); -int __weak arch_kimage_file_post_load_cleanup(struct kimage *image); -int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, - unsigned long buf_len); int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, unsigned int relsec); int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, -- cgit v1.2.3 From babac4a84a88842bec477a5bdada1460f3bc374c Mon Sep 17 00:00:00 2001 From: AKASHI Takahiro Date: Fri, 13 Apr 2018 15:36:06 -0700 Subject: kexec_file, x86: move re-factored code to generic side In the previous patches, commonly-used routines, exclude_mem_range() and prepare_elf64_headers(), were carved out. Now place them in kexec common code. A prefix "crash_" is given to each of their names to avoid possible name collisions. Link: http://lkml.kernel.org/r/20180306102303.9063-8-takahiro.akashi@linaro.org Signed-off-by: AKASHI Takahiro Acked-by: Dave Young Tested-by: Dave Young Cc: Vivek Goyal Cc: Baoquan He Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kexec.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'include') diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 102c725421a1..68865fd51aad 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -168,6 +168,25 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf, int (*func)(struct resource *, void *)); extern int kexec_add_buffer(struct kexec_buf *kbuf); int kexec_locate_mem_hole(struct kexec_buf *kbuf); + +/* Alignment required for elf header segment */ +#define ELF_CORE_HEADER_ALIGN 4096 + +struct crash_mem_range { + u64 start, end; +}; + +struct crash_mem { + unsigned int max_nr_ranges; + unsigned int nr_ranges; + struct crash_mem_range ranges[0]; +}; + +extern int crash_exclude_mem_range(struct crash_mem *mem, + unsigned long long mstart, + unsigned long long mend); +extern int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map, + void **addr, unsigned long *sz); #endif /* CONFIG_KEXEC_FILE */ struct kimage { -- cgit v1.2.3 From ee6ebeda8ddc350700168f2c8052a97bd9c11e5b Mon Sep 17 00:00:00 2001 From: Philipp Rudo Date: Fri, 13 Apr 2018 15:36:10 -0700 Subject: include/linux/kexec.h: silence compile warnings Patch series "kexec_file: Clean up purgatory load", v2. Following the discussion with Dave and AKASHI, here are the common code patches extracted from my recent patch set (Add kexec_file_load support to s390) [1]. The patches were extracted to allow upstream integration together with AKASHI's common code patches before the arch code gets adjusted to the new base. The reason for this series is to prepare common code for adding kexec_file_load to s390 as well as cleaning up the mis-use of the sh_offset field during purgatory load. In detail this series contains: Patch #1&2: Minor cleanups/fixes. Patch #3-9: Clean up the purgatory load/relocation code. Especially remove the mis-use of the purgatory_info->sechdrs->sh_offset field, currently holding a pointer into either kexec_purgatory (ro) or purgatory_buf (rw) depending on the section. With these patches the section address will be calculated verbosely and sh_offset will contain the offset of the section in the stripped purgatory binary (purgatory_buf). Patch #10: Allows architectures to set the purgatory load address. This patch is important for s390 as the kernel and purgatory have to be loaded to fixed addresses. In current code this is impossible as the purgatory load is opaque to the architecture. Patch #11: Moves x86 purgatories sha implementation to common lib/ directory to allow reuse in other architectures. This patch (of 11) When building the kernel with CONFIG_KEXEC_FILE enabled gcc prints a compile warning multiple times. In file included from /linux/init/initramfs.c:526:0: /include/linux/kexec.h:120:9: warning: `struct kimage' declared inside parameter list [enabled by default] unsigned long cmdline_len); ^ This is because the typedefs for kexec_file_load uses struct kimage before it is declared. Fix this by simply forward declaring struct kimage. Link: http://lkml.kernel.org/r/20180321112751.22196-2-prudo@linux.vnet.ibm.com Signed-off-by: Philipp Rudo Acked-by: Dave Young Cc: Eric Biederman Cc: Vivek Goyal Cc: Michael Ellerman Cc: Thiago Jung Bauermann Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: AKASHI Takahiro Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kexec.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 68865fd51aad..08b8b9d00f97 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -114,6 +114,8 @@ struct purgatory_info { unsigned long purgatory_load_addr; }; +struct kimage; + typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size); typedef void *(kexec_load_t)(struct kimage *image, char *kernel_buf, unsigned long kernel_len, char *initrd, -- cgit v1.2.3 From 65c225d3280542f3ea145e052215ce0538f6bb69 Mon Sep 17 00:00:00 2001 From: Philipp Rudo Date: Fri, 13 Apr 2018 15:36:17 -0700 Subject: kernel/kexec_file.c: make purgatory_info->ehdr const The kexec_purgatory buffer is read-only. Thus all pointers into kexec_purgatory are read-only, too. Point this out by explicitly marking purgatory_info->ehdr as 'const' and update the comments in purgatory_info. Link: http://lkml.kernel.org/r/20180321112751.22196-4-prudo@linux.vnet.ibm.com Signed-off-by: Philipp Rudo Acked-by: Dave Young Cc: AKASHI Takahiro Cc: Eric Biederman Cc: Heiko Carstens Cc: Ingo Molnar Cc: Martin Schwidefsky Cc: Michael Ellerman Cc: Thiago Jung Bauermann Cc: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kexec.h | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'include') diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 08b8b9d00f97..8c5819d1a808 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -99,14 +99,19 @@ struct compat_kexec_segment { #ifdef CONFIG_KEXEC_FILE struct purgatory_info { - /* Pointer to elf header of read only purgatory */ - Elf_Ehdr *ehdr; - - /* Pointer to purgatory sechdrs which are modifiable */ + /* + * Pointer to elf header at the beginning of kexec_purgatory. + * Note: kexec_purgatory is read only + */ + const Elf_Ehdr *ehdr; + /* + * Temporary, modifiable buffer for sechdrs used for relocation. + * This memory can be freed post image load. + */ Elf_Shdr *sechdrs; /* - * Temporary buffer location where purgatory is loaded and relocated - * This memory can be freed post image load + * Temporary, modifiable buffer for stripped purgatory used for + * relocation. This memory can be freed post image load. */ void *purgatory_buf; -- cgit v1.2.3 From 8aec395b8478310521031157ef5d44ef19c2c581 Mon Sep 17 00:00:00 2001 From: Philipp Rudo Date: Fri, 13 Apr 2018 15:36:24 -0700 Subject: kernel/kexec_file.c: use read-only sections in arch_kexec_apply_relocations* When the relocations are applied to the purgatory only the section the relocations are applied to is writable. The other sections, i.e. the symtab and .rel/.rela, are in read-only kexec_purgatory. Highlight this by marking the corresponding variables as 'const'. While at it also change the signatures of arch_kexec_apply_relocations* to take section pointers instead of just the index of the relocation section. This removes the second lookup and sanity check of the sections in arch code. Link: http://lkml.kernel.org/r/20180321112751.22196-6-prudo@linux.vnet.ibm.com Signed-off-by: Philipp Rudo Acked-by: Dave Young Cc: AKASHI Takahiro Cc: Eric Biederman Cc: Heiko Carstens Cc: Ingo Molnar Cc: Martin Schwidefsky Cc: Michael Ellerman Cc: Thiago Jung Bauermann Cc: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kexec.h | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 8c5819d1a808..0e389b9b7722 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -171,6 +171,15 @@ struct kexec_buf { bool top_down; }; +int __weak arch_kexec_apply_relocations_add(struct purgatory_info *pi, + Elf_Shdr *section, + const Elf_Shdr *relsec, + const Elf_Shdr *symtab); +int __weak arch_kexec_apply_relocations(struct purgatory_info *pi, + Elf_Shdr *section, + const Elf_Shdr *relsec, + const Elf_Shdr *symtab); + int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf, int (*func)(struct resource *, void *)); extern int kexec_add_buffer(struct kexec_buf *kbuf); @@ -304,10 +313,6 @@ int crash_shrink_memory(unsigned long new_size); size_t crash_get_memory_size(void); void crash_free_reserved_phys_range(unsigned long begin, unsigned long end); -int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, - Elf_Shdr *sechdrs, unsigned int relsec); -int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, - unsigned int relsec); void arch_kexec_protect_crashkres(void); void arch_kexec_unprotect_crashkres(void); -- cgit v1.2.3 From 3be3f61d25e04ecf90d65d52fad632af5ba8805b Mon Sep 17 00:00:00 2001 From: Philipp Rudo Date: Fri, 13 Apr 2018 15:36:43 -0700 Subject: kernel/kexec_file.c: allow archs to set purgatory load address 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. Link: http://lkml.kernel.org/r/20180321112751.22196-11-prudo@linux.vnet.ibm.com Signed-off-by: Philipp Rudo Reviewed-by: Martin Schwidefsky Acked-by: Dave Young Cc: AKASHI Takahiro Cc: Eric Biederman Cc: Heiko Carstens Cc: Ingo Molnar Cc: Michael Ellerman Cc: Thiago Jung Bauermann Cc: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kexec.h | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) (limited to 'include') diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 0e389b9b7722..9e4e638fb505 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; @@ -171,6 +168,12 @@ struct kexec_buf { bool top_down; }; +int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf); +int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name, + void *buf, unsigned int size, + bool get_value); +void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name); + int __weak arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section, const Elf_Shdr *relsec, @@ -266,14 +269,6 @@ extern void machine_kexec_cleanup(struct kimage *image); 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_purgatory_get_set_symbol(struct kimage *image, - const char *name, void *buf, - unsigned int size, bool get_value); -extern void *kexec_purgatory_get_symbol_addr(struct kimage *image, - const char *name); extern void __crash_kexec(struct pt_regs *); extern void crash_kexec(struct pt_regs *); int kexec_should_crash(struct task_struct *); -- cgit v1.2.3 From df6f2801f511b07c08c110fe9f047a34cb40286f Mon Sep 17 00:00:00 2001 From: Philipp Rudo Date: Fri, 13 Apr 2018 15:36:46 -0700 Subject: kernel/kexec_file.c: move purgatories sha256 to common code The code to verify the new kernels sha digest is applicable for all architectures. Move it to common code. One problem is the string.c implementation on x86. Currently sha256 includes x86/boot/string.h which defines memcpy and memset to be gcc builtins. By moving the sha256 implementation to common code and changing the include to linux/string.h both functions are no longer defined. Thus definitions have to be provided in x86/purgatory/string.c Link: http://lkml.kernel.org/r/20180321112751.22196-12-prudo@linux.vnet.ibm.com Signed-off-by: Philipp Rudo Acked-by: Dave Young Cc: AKASHI Takahiro Cc: Eric Biederman Cc: Heiko Carstens Cc: Ingo Molnar Cc: Martin Schwidefsky Cc: Michael Ellerman Cc: Thiago Jung Bauermann Cc: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/sha256.h | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 include/linux/sha256.h (limited to 'include') diff --git a/include/linux/sha256.h b/include/linux/sha256.h new file mode 100644 index 000000000000..244fe01a65fb --- /dev/null +++ b/include/linux/sha256.h @@ -0,0 +1,30 @@ +/* + * Copyright (C) 2014 Red Hat Inc. + * + * Author: Vivek Goyal + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ + +#ifndef SHA256_H +#define SHA256_H + +#include +#include + +/* + * Stand-alone implementation of the SHA256 algorithm. It is designed to + * have as little dependencies as possible so it can be used in the + * kexec_file purgatory. In other cases you should use the implementation in + * crypto/. + * + * For details see lib/sha256.c + */ + +extern int sha256_init(struct sha256_state *sctx); +extern int sha256_update(struct sha256_state *sctx, const u8 *input, + unsigned int length); +extern int sha256_final(struct sha256_state *sctx, u8 *hash); + +#endif /* SHA256_H */ -- cgit v1.2.3