cregit-Linux how code gets into the kernel

Release 4.16 include/linux/kexec.h

Directory: include/linux
/* 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 of read only purgatory */
	
Elf_Ehdr *ehdr;

	/* Pointer to purgatory sechdrs which are modifiable */
	
Elf_Shdr *sechdrs;
	/*
         * Temporary buffer location where purgatory is loaded and relocated
         * 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;
};


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_VERIFY_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_VERIFY_SIG
	
kexec_verify_sig_t *verify_sig;
#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 __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);
#endif /* CONFIG_KEXEC_FILE */


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 */
	
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 asmlinkage long sys_kexec_load(unsigned long entry,
					unsigned long nr_segments,
					struct kexec_segment __user *segments,
					unsigned long flags);
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 *);
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);

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,
					unsigned int relsec);
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); }

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#endif #ifndef boot_pfn_to_page
static inline struct page *boot_pfn_to_page(unsigned long boot_pfn) { return pfn_to_page(boot_pfn); }

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Russell King19100.00%1100.00%
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#endif #ifndef phys_to_boot_phys
static inline unsigned long phys_to_boot_phys(phys_addr_t phys) { return phys; }

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Russell King14100.00%1100.00%
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#endif #ifndef boot_phys_to_phys
static inline phys_addr_t boot_phys_to_phys(unsigned long boot_phys) { return boot_phys; }

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Russell King14100.00%1100.00%
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#endif
static inline unsigned long virt_to_boot_phys(void *addr) { return phys_to_boot_phys(__pa((unsigned long)addr)); }

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Russell King25100.00%1100.00%
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static inline void *boot_phys_to_virt(unsigned long entry) { return phys_to_virt(boot_phys_to_phys(entry)); }

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Russell King21100.00%1100.00%
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#ifndef arch_kexec_post_alloc_pages
static inline int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp) { return 0; }

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Tom Lendacky21100.00%1100.00%
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#endif #ifndef arch_kexec_pre_free_pages
static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) { }

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Tom Lendacky14100.00%1100.00%
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#endif #else /* !CONFIG_KEXEC_CORE */ struct pt_regs; struct task_struct;
static inline void __crash_kexec(struct pt_regs *regs) { }

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Hidehiro Kawai11100.00%1100.00%
Total11100.00%1100.00%


static inline void crash_kexec(struct pt_regs *regs) { }

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Eric W. Biedermann763.64%150.00%
Alexander Nyberg436.36%150.00%
Total11100.00%2100.00%


static inline int kexec_should_crash(struct task_struct *p) { return 0; }

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Alexander Nyberg15100.00%1100.00%
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static inline int kexec_crash_loaded(void) { return 0; }

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Petr Tesarik12100.00%1100.00%
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#define kexec_in_progress false #endif /* CONFIG_KEXEC_CORE */ #endif /* !defined(__ASSEBMLY__) */ #endif /* LINUX_KEXEC_H */

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PersonTokensPropCommitsCommitProp
Eric W. Biedermann27322.21%12.17%
Vivek Goyal16413.34%510.87%
Xunlei Pang14812.04%36.52%
Russell King13611.07%24.35%
Dave Young967.81%24.35%
Thiago Jung Bauermann836.75%36.52%
Tom Lendacky483.91%24.35%
Huang Ying473.82%36.52%
Geoff Levand463.74%24.35%
Alexander Nyberg362.93%12.17%
Hidehiro Kawai201.63%12.17%
Michael Holzheu181.46%24.35%
Petr Tesarik181.46%12.17%
Américo Wang131.06%12.17%
Magnus Damm120.98%12.17%
Anton Blanchard120.98%12.17%
Zou Nan hai110.90%12.17%
Martin Schwidefsky80.65%12.17%
Jeff Moyer60.49%12.17%
Khalid Aziz50.41%12.17%
Yinghai Lu50.41%12.17%
Hari Bathini40.33%12.17%
Vitaly Kuznetsov40.33%12.17%
Kees Cook40.33%12.17%
Simon Horman30.24%12.17%
Haren Myneni30.24%12.17%
Maximilian Attems20.16%12.17%
Tejun Heo10.08%12.17%
David Howells10.08%12.17%
Bernhard Walle10.08%12.17%
Greg Kroah-Hartman10.08%12.17%
Total1229100.00%46100.00%
Directory: include/linux
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