LXR linux/include/linux/crash

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef LINUX_CRASH_DUMP_H
   3#define LINUX_CRASH_DUMP_H
   4
   5#include <linux/kexec.h>
   6#include <linux/proc_fs.h>
   7#include <linux/elf.h>
   8#include <uapi/linux/vmcore.h>
   9
  10#include <asm/pgtable.h> /* for pgprot_t */
  11
  12#ifdef CONFIG_CRASH_DUMP
  13#define ELFCORE_ADDR_MAX        (-1ULL)
  14#define ELFCORE_ADDR_ERR        (-2ULL)
  15
  16extern unsigned long long elfcorehdr_addr;
  17extern unsigned long long elfcorehdr_size;
  18
  19extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size);
  20extern void elfcorehdr_free(unsigned long long addr);
  21extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos);
  22extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos);
  23extern int remap_oldmem_pfn_range(struct vm_area_struct *vma,
  24                                  unsigned long from, unsigned long pfn,
  25                                  unsigned long size, pgprot_t prot);
  26
  27extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
  28                                                unsigned long, int);
  29extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf,
  30                                          size_t csize, unsigned long offset,
  31                                          int userbuf);
  32
  33void vmcore_cleanup(void);
  34
  35/* Architecture code defines this if there are other possible ELF
  36 * machine types, e.g. on bi-arch capable hardware. */
  37#ifndef vmcore_elf_check_arch_cross
  38#define vmcore_elf_check_arch_cross(x) 0
  39#endif
  40
  41/*
  42 * Architecture code can redefine this if there are any special checks
  43 * needed for 32-bit ELF or 64-bit ELF vmcores.  In case of 32-bit
  44 * only architecture, vmcore_elf64_check_arch can be set to zero.
  45 */
  46#ifndef vmcore_elf32_check_arch
  47#define vmcore_elf32_check_arch(x) elf_check_arch(x)
  48#endif
  49
  50#ifndef vmcore_elf64_check_arch
  51#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
  52#endif
  53
  54/*
  55 * is_kdump_kernel() checks whether this kernel is booting after a panic of
  56 * previous kernel or not. This is determined by checking if previous kernel
  57 * has passed the elf core header address on command line.
  58 *
  59 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
  60 * return true if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic
  61 * of previous kernel.
  62 */
  63
  64static inline bool is_kdump_kernel(void)
  65{
  66        return elfcorehdr_addr != ELFCORE_ADDR_MAX;
  67}
  68
  69/* is_vmcore_usable() checks if the kernel is booting after a panic and
  70 * the vmcore region is usable.
  71 *
  72 * This makes use of the fact that due to alignment -2ULL is not
  73 * a valid pointer, much in the vain of IS_ERR(), except
  74 * dealing directly with an unsigned long long rather than a pointer.
  75 */
  76
  77static inline int is_vmcore_usable(void)
  78{
  79        return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
  80}
  81
  82/* vmcore_unusable() marks the vmcore as unusable,
  83 * without disturbing the logic of is_kdump_kernel()
  84 */
  85
  86static inline void vmcore_unusable(void)
  87{
  88        if (is_kdump_kernel())
  89                elfcorehdr_addr = ELFCORE_ADDR_ERR;
  90}
  91
  92#define HAVE_OLDMEM_PFN_IS_RAM 1
  93extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
  94extern void unregister_oldmem_pfn_is_ram(void);
  95
  96#else /* !CONFIG_CRASH_DUMP */
  97static inline bool is_kdump_kernel(void) { return 0; }
  98#endif /* CONFIG_CRASH_DUMP */
  99
 100extern unsigned long saved_max_pfn;
 101
 102/* Device Dump information to be filled by drivers */
 103struct vmcoredd_data {
 104        char dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Unique name of the dump */
 105        unsigned int size;                       /* Size of the dump */
 106        /* Driver's registered callback to be invoked to collect dump */
 107        int (*vmcoredd_callback)(struct vmcoredd_data *data, void *buf);
 108};
 109
 110#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
 111int vmcore_add_device_dump(struct vmcoredd_data *data);
 112#else
 113static inline int vmcore_add_device_dump(struct vmcoredd_data *data)
 114{
 115        return -EOPNOTSUPP;
 116}
 117#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
 118#endif /* LINUX_CRASHDUMP_H */
 119