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 16 extern unsigned long long elfcorehdr_addr; 17 extern unsigned long long elfcorehdr_size; 18 19 extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size); 20 extern void elfcorehdr_free(unsigned long long addr); 21 extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos); 22 extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos); 23 extern 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 27 extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, 28 unsigned long, int); 29 extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, 30 size_t csize, unsigned long offset, 31 int userbuf); 32 33 void 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 64 static 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 77 static 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 86 static 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 93 extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn)); 94 extern void unregister_oldmem_pfn_is_ram(void); 95 96 #else /* !CONFIG_CRASH_DUMP */ 97 static inline bool is_kdump_kernel(void) { return 0; } 98 #endif /* CONFIG_CRASH_DUMP */ 99 100 extern unsigned long saved_max_pfn; 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 #endif /* LINUX_CRASHDUMP_H */ 119