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 /* For IS_ENABLED(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 #ifdef CONFIG_CRASH_DUMP 21 extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size); 22 extern void elfcorehdr_free(unsigned long long addr); 23 extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos); 24 extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos); 25 extern int remap_oldmem_pfn_range(struct vm_area_struct *vma, 26 unsigned long from, unsigned long pfn, 27 unsigned long size, pgprot_t prot); 28 29 extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, 30 unsigned long, int); 31 extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, 32 size_t csize, unsigned long offset, 33 int userbuf); 34 35 void vmcore_cleanup(void); 36 37 /* Architecture code defines this if there are other possible ELF 38 * machine types, e.g. on bi-arch capable hardware. */ 39 #ifndef vmcore_elf_check_arch_cross 40 #define vmcore_elf_check_arch_cross(x) 0 41 #endif 42 43 /* 44 * Architecture code can redefine this if there are any special checks 45 * needed for 32-bit ELF or 64-bit ELF vmcores. In case of 32-bit 46 * only architecture, vmcore_elf64_check_arch can be set to zero. 47 */ 48 #ifndef vmcore_elf32_check_arch 49 #define vmcore_elf32_check_arch(x) elf_check_arch(x) 50 #endif 51 52 #ifndef vmcore_elf64_check_arch 53 #define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x)) 54 #endif 55 56 /* 57 * is_kdump_kernel() checks whether this kernel is booting after a panic of 58 * previous kernel or not. This is determined by checking if previous kernel 59 * has passed the elf core header address on command line. 60 * 61 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will 62 * return true if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic 63 * of previous kernel. 64 */ 65 66 static inline bool is_kdump_kernel(void) 67 { 68 return elfcorehdr_addr != ELFCORE_ADDR_MAX; 69 } 70 71 /* is_vmcore_usable() checks if the kernel is booting after a panic and 72 * the vmcore region is usable. 73 * 74 * This makes use of the fact that due to alignment -2ULL is not 75 * a valid pointer, much in the vain of IS_ERR(), except 76 * dealing directly with an unsigned long long rather than a pointer. 77 */ 78 79 static inline int is_vmcore_usable(void) 80 { 81 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; 82 } 83 84 /* vmcore_unusable() marks the vmcore as unusable, 85 * without disturbing the logic of is_kdump_kernel() 86 */ 87 88 static inline void vmcore_unusable(void) 89 { 90 if (is_kdump_kernel()) 91 elfcorehdr_addr = ELFCORE_ADDR_ERR; 92 } 93 94 #define HAVE_OLDMEM_PFN_IS_RAM 1 95 extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn)); 96 extern void unregister_oldmem_pfn_is_ram(void); 97 98 #else /* !CONFIG_CRASH_DUMP */ 99 static inline bool is_kdump_kernel(void) { return 0; } 100 #endif /* CONFIG_CRASH_DUMP */ 101 102 /* Device Dump information to be filled by drivers */ 103 struct 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 111 int vmcore_add_device_dump(struct vmcoredd_data *data); 112 #else 113 static inline int vmcore_add_device_dump(struct vmcoredd_data *data) 114 { 115 return -EOPNOTSUPP; 116 } 117 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ 118 119 #ifdef CONFIG_PROC_VMCORE 120 ssize_t read_from_oldmem(char *buf, size_t count, 121 u64 *ppos, int userbuf, 122 bool encrypted); 123 #else 124 static inline ssize_t read_from_oldmem(char *buf, size_t count, 125 u64 *ppos, int userbuf, 126 bool encrypted) 127 { 128 return -EOPNOTSUPP; 129 } 130 #endif /* CONFIG_PROC_VMCORE */ 131 132 #endif /* LINUX_CRASHDUMP_H */ 133