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 17 extern unsigned long long elfcorehdr_addr; 18 extern unsigned long long elfcorehdr_size; 19 20 extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size); 21 extern void elfcorehdr_free(unsigned long long addr); 22 extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos); 23 extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos); 24 extern 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 28 extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, 29 unsigned long, int); 30 extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, 31 size_t csize, unsigned long offset, 32 int userbuf); 33 34 void 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 65 static 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 78 static 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 87 static 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 94 extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn)); 95 extern void unregister_oldmem_pfn_is_ram(void); 96 97 #else /* !CONFIG_CRASH_DUMP */ 98 static inline bool is_kdump_kernel(void) { return 0; } 99 #endif /* CONFIG_CRASH_DUMP */ 100 101 /* Device Dump information to be filled by drivers */ 102 struct 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 110 int vmcore_add_device_dump(struct vmcoredd_data *data); 111 #else 112 static 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 119 ssize_t read_from_oldmem(char *buf, size_t count, 120 u64 *ppos, int userbuf, 121 bool encrypted); 122 #else 123 static 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