kexec.h
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef LINUX_KEXEC_H
#define LINUX_KEXEC_H
#define IND_DESTINATION_BIT 0
#define IND_INDIRECTION_BIT 1
#define IND_DONE_BIT 2
#define IND_SOURCE_BIT 3
#define IND_DESTINATION (1 << IND_DESTINATION_BIT)
#define IND_INDIRECTION (1 << IND_INDIRECTION_BIT)
#define IND_DONE (1 << IND_DONE_BIT)
#define IND_SOURCE (1 << IND_SOURCE_BIT)
#define IND_FLAGS (IND_DESTINATION | IND_INDIRECTION | IND_DONE | IND_SOURCE)
#if !defined(__ASSEMBLY__)
#include <linux/crash_core.h>
#include <asm/io.h>
#include <uapi/linux/kexec.h>
#ifdef CONFIG_KEXEC_CORE
#include <linux/list.h>
#include <linux/compat.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <asm/kexec.h>
/* Verify architecture specific macros are defined */
#ifndef KEXEC_SOURCE_MEMORY_LIMIT
#error KEXEC_SOURCE_MEMORY_LIMIT not defined
#endif
#ifndef KEXEC_DESTINATION_MEMORY_LIMIT
#error KEXEC_DESTINATION_MEMORY_LIMIT not defined
#endif
#ifndef KEXEC_CONTROL_MEMORY_LIMIT
#error KEXEC_CONTROL_MEMORY_LIMIT not defined
#endif
#ifndef KEXEC_CONTROL_MEMORY_GFP
#define KEXEC_CONTROL_MEMORY_GFP (GFP_KERNEL | __GFP_NORETRY)
#endif
#ifndef KEXEC_CONTROL_PAGE_SIZE
#error KEXEC_CONTROL_PAGE_SIZE not defined
#endif
#ifndef KEXEC_ARCH
#error KEXEC_ARCH not defined
#endif
#ifndef KEXEC_CRASH_CONTROL_MEMORY_LIMIT
#define KEXEC_CRASH_CONTROL_MEMORY_LIMIT KEXEC_CONTROL_MEMORY_LIMIT
#endif
#ifndef KEXEC_CRASH_MEM_ALIGN
#define KEXEC_CRASH_MEM_ALIGN PAGE_SIZE
#endif
#define KEXEC_CORE_NOTE_NAME CRASH_CORE_NOTE_NAME
/*
* This structure is used to hold the arguments that are used when loading
* kernel binaries.
*/
typedef unsigned long kimage_entry_t;
struct kexec_segment {
/*
* This pointer can point to user memory if kexec_load() system
* call is used or will point to kernel memory if
* kexec_file_load() system call is used.
*
* Use ->buf when expecting to deal with user memory and use ->kbuf
* when expecting to deal with kernel memory.
*/
union {
void __user *buf;
void *kbuf;
};
size_t bufsz;
unsigned long mem;
size_t memsz;
};
#ifdef CONFIG_COMPAT
struct compat_kexec_segment {
compat_uptr_t buf;
compat_size_t bufsz;
compat_ulong_t mem; /* User space sees this as a (void *) ... */
compat_size_t memsz;
};
#endif
#ifdef CONFIG_KEXEC_FILE
struct purgatory_info {
/*
* 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, modifiable buffer for stripped purgatory used for
* relocation. This memory can be freed post image load.
*/
void *purgatory_buf;
};
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,
unsigned long initrd_len, char *cmdline,
unsigned long cmdline_len);
typedef int (kexec_cleanup_t)(void *loader_data);
#ifdef CONFIG_KEXEC_SIG
typedef int (kexec_verify_sig_t)(const char *kernel_buf,
unsigned long kernel_len);
#endif
struct kexec_file_ops {
kexec_probe_t *probe;
kexec_load_t *load;
kexec_cleanup_t *cleanup;
#ifdef CONFIG_KEXEC_SIG
kexec_verify_sig_t *verify_sig;
#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);
int kexec_image_post_load_cleanup_default(struct kimage *image);
/*
* If kexec_buf.mem is set to this value, kexec_locate_mem_hole()
* will try to allocate free memory. Arch may overwrite it.
*/
#ifndef KEXEC_BUF_MEM_UNKNOWN
#define KEXEC_BUF_MEM_UNKNOWN 0
#endif
/**
* struct kexec_buf - parameters for finding a place for a buffer in memory
* @image: kexec image in which memory to search.
* @buffer: Contents which will be copied to the allocated memory.
* @bufsz: Size of @buffer.
* @mem: On return will have address of the buffer in memory.
* @memsz: Size for the buffer in memory.
* @buf_align: Minimum alignment needed.
* @buf_min: The buffer can't be placed below this address.
* @buf_max: The buffer can't be placed above this address.
* @top_down: Allocate from top of memory.
*/
struct kexec_buf {
struct kimage *image;
void *buffer;
unsigned long bufsz;
unsigned long mem;
unsigned long memsz;
unsigned long buf_align;
unsigned long buf_min;
unsigned long buf_max;
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);
/* Architectures may override the below functions */
int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
unsigned long buf_len);
void *arch_kexec_kernel_image_load(struct kimage *image);
int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
Elf_Shdr *section,
const Elf_Shdr *relsec,
const Elf_Shdr *symtab);
int arch_kexec_apply_relocations(struct purgatory_info *pi,
Elf_Shdr *section,
const Elf_Shdr *relsec,
const Elf_Shdr *symtab);
int arch_kimage_file_post_load_cleanup(struct kimage *image);
#ifdef CONFIG_KEXEC_SIG
int arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
unsigned long buf_len);
#endif
int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf);
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[];
};
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 */
#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;
};
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;
kimage_entry_t *last_entry;
unsigned long start;
struct page *control_code_page;
struct page *swap_page;
void *vmcoreinfo_data_copy; /* locates in the crash memory */
unsigned long nr_segments;
struct kexec_segment segment[KEXEC_SEGMENT_MAX];
struct list_head control_pages;
struct list_head dest_pages;
struct list_head unusable_pages;
/* Address of next control page to allocate for crash kernels. */
unsigned long control_page;
/* Flags to indicate special processing */
unsigned int type : 1;
#define KEXEC_TYPE_DEFAULT 0
#define KEXEC_TYPE_CRASH 1
unsigned int preserve_context : 1;
/* If set, we are using file mode kexec syscall */
unsigned int file_mode:1;
#ifdef ARCH_HAS_KIMAGE_ARCH
struct kimage_arch arch;
#endif
#ifdef CONFIG_KEXEC_FILE
/* Additional fields for file based kexec syscall */
void *kernel_buf;
unsigned long kernel_buf_len;
void *initrd_buf;
unsigned long initrd_buf_len;
char *cmdline_buf;
unsigned long cmdline_buf_len;
/* File operations provided by image loader */
const struct kexec_file_ops *fops;
/* Image loader handling the kernel can store a pointer here */
void *image_loader_data;
/* Information for loading purgatory */
struct purgatory_info purgatory_info;
#endif
};
/* kexec interface functions */
extern void machine_kexec(struct kimage *image);
extern int machine_kexec_prepare(struct kimage *image);
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 void __crash_kexec(struct pt_regs *);
extern void crash_kexec(struct pt_regs *);
int kexec_should_crash(struct task_struct *);
int kexec_crash_loaded(void);
void crash_save_cpu(struct pt_regs *regs, int cpu);
extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
extern struct kimage *kexec_image;
extern struct kimage *kexec_crash_image;
extern int kexec_load_disabled;
#ifndef kexec_flush_icache_page
#define kexec_flush_icache_page(page)
#endif
/* List of defined/legal kexec flags */
#ifndef CONFIG_KEXEC_JUMP
#define KEXEC_FLAGS KEXEC_ON_CRASH
#else
#define KEXEC_FLAGS (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT)
#endif
/* List of defined/legal kexec file flags */
#define KEXEC_FILE_FLAGS (KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
KEXEC_FILE_NO_INITRAMFS)
/* Location of a reserved region to hold the crash kernel.
*/
extern struct resource crashk_res;
extern struct resource crashk_low_res;
extern note_buf_t __percpu *crash_notes;
/* flag to track if kexec reboot is in progress */
extern bool kexec_in_progress;
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);
void arch_kexec_protect_crashkres(void);
void arch_kexec_unprotect_crashkres(void);
#ifndef page_to_boot_pfn
static inline unsigned long page_to_boot_pfn(struct page *page)
{
return page_to_pfn(page);
}
#endif
#ifndef boot_pfn_to_page
static inline struct page *boot_pfn_to_page(unsigned long boot_pfn)
{
return pfn_to_page(boot_pfn);
}
#endif
#ifndef phys_to_boot_phys
static inline unsigned long phys_to_boot_phys(phys_addr_t phys)
{
return phys;
}
#endif
#ifndef boot_phys_to_phys
static inline phys_addr_t boot_phys_to_phys(unsigned long boot_phys)
{
return boot_phys;
}
#endif
static inline unsigned long virt_to_boot_phys(void *addr)
{
return phys_to_boot_phys(__pa((unsigned long)addr));
}
static inline void *boot_phys_to_virt(unsigned long entry)
{
return phys_to_virt(boot_phys_to_phys(entry));
}
#ifndef arch_kexec_post_alloc_pages
static inline int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp) { return 0; }
#endif
#ifndef arch_kexec_pre_free_pages
static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) { }
#endif
#else /* !CONFIG_KEXEC_CORE */
struct pt_regs;
struct task_struct;
static inline void __crash_kexec(struct pt_regs *regs) { }
static inline void crash_kexec(struct pt_regs *regs) { }
static inline int kexec_should_crash(struct task_struct *p) { return 0; }
static inline int kexec_crash_loaded(void) { return 0; }
#define kexec_in_progress false
#endif /* CONFIG_KEXEC_CORE */
#endif /* !defined(__ASSEBMLY__) */
#endif /* LINUX_KEXEC_H */