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 <linux/pgtable.h>
   9#include <uapi/linux/vmcore.h>
  10
  11#include <linux/pgtable.h> /* for pgprot_t */
  12
  13#ifdef CONFIG_CRASH_DUMP
  14#define ELFCORE_ADDR_MAX        (-1ULL)
  15#define ELFCORE_ADDR_ERR        (-2ULL)
  16
  17extern unsigned long long elfcorehdr_addr;
  18extern unsigned long long elfcorehdr_size;
  19
  20extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size);
  21extern void elfcorehdr_free(unsigned long long addr);
  22extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos);
  23extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos);
  24extern int remap_oldmem_pfn_range(struct vm_area_struct *vma,
  25                                  unsigned long from, unsigned long pfn,
  26                                  unsigned long size, pgprot_t prot);
  27
  28extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
  29                                                unsigned long, int);
  30extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf,
  31                                          size_t csize, unsigned long offset,
  32                                          int userbuf);
  33
  34void vmcore_cleanup(void);
  35
  36/* Architecture code defines this if there are other possible ELF
  37 * machine types, e.g. on bi-arch capable hardware. */
  38#ifndef vmcore_elf_check_arch_cross
  39#define vmcore_elf_check_arch_cross(x) 0
  40#endif
  41
  42/*
  43 * Architecture code can redefine this if there are any special checks
  44 * needed for 32-bit ELF or 64-bit ELF vmcores.  In case of 32-bit
  45 * only architecture, vmcore_elf64_check_arch can be set to zero.
  46 */
  47#ifndef vmcore_elf32_check_arch
  48#define vmcore_elf32_check_arch(x) elf_check_arch(x)
  49#endif
  50
  51#ifndef vmcore_elf64_check_arch
  52#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
  53#endif
  54
  55/*
  56 * is_kdump_kernel() checks whether this kernel is booting after a panic of
  57 * previous kernel or not. This is determined by checking if previous kernel
  58 * has passed the elf core header address on command line.
  59 *
  60 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
  61 * return true if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic
  62 * of previous kernel.
  63 */
  64
  65static inline bool is_kdump_kernel(void)
  66{
  67        return elfcorehdr_addr != ELFCORE_ADDR_MAX;
  68}
  69
  70/* is_vmcore_usable() checks if the kernel is booting after a panic and
  71 * the vmcore region is usable.
  72 *
  73 * This makes use of the fact that due to alignment -2ULL is not
  74 * a valid pointer, much in the vain of IS_ERR(), except
  75 * dealing directly with an unsigned long long rather than a pointer.
  76 */
  77
  78static inline int is_vmcore_usable(void)
  79{
  80        return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
  81}
  82
  83/* vmcore_unusable() marks the vmcore as unusable,
  84 * without disturbing the logic of is_kdump_kernel()
  85 */
  86
  87static inline void vmcore_unusable(void)
  88{
  89        if (is_kdump_kernel())
  90                elfcorehdr_addr = ELFCORE_ADDR_ERR;
  91}
  92
  93#define HAVE_OLDMEM_PFN_IS_RAM 1
  94extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
  95extern void unregister_oldmem_pfn_is_ram(void);
  96
  97#else /* !CONFIG_CRASH_DUMP */
  98static inline bool is_kdump_kernel(void) { return 0; }
  99#endif /* CONFIG_CRASH_DUMP */
 100
 101/* Device Dump information to be filled by drivers */
 102struct vmcoredd_data {
 103        char dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Unique name of the dump */
 104        unsigned int size;                       /* Size of the dump */
 105        /* Driver's registered callback to be invoked to collect dump */
 106        int (*vmcoredd_callback)(struct vmcoredd_data *data, void *buf);
 107};
 108
 109#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
 110int vmcore_add_device_dump(struct vmcoredd_data *data);
 111#else
 112static inline int vmcore_add_device_dump(struct vmcoredd_data *data)
 113{
 114        return -EOPNOTSUPP;
 115}
 116#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
 117
 118#ifdef CONFIG_PROC_VMCORE
 119ssize_t read_from_oldmem(char *buf, size_t count,
 120                         u64 *ppos, int userbuf,
 121                         bool encrypted);
 122#else
 123static inline ssize_t read_from_oldmem(char *buf, size_t count,
 124                                       u64 *ppos, int userbuf,
 125                                       bool encrypted)
 126{
 127        return -EOPNOTSUPP;
 128}
 129#endif /* CONFIG_PROC_VMCORE */
 130
 131#endif /* LINUX_CRASHDUMP_H */
 132