1 #ifndef LINUX_CRASH_DUMP_H 2 #define LINUX_CRASH_DUMP_H 3 4 #ifdef CONFIG_CRASH_DUMP 5 #include <linux/kexec.h> 6 #include <linux/smp_lock.h> 7 #include <linux/device.h> 8 #include <linux/proc_fs.h> 9 10 #define ELFCORE_ADDR_MAX (-1ULL) 11 #define ELFCORE_ADDR_ERR (-2ULL) 12 13 extern unsigned long long elfcorehdr_addr; 14 15 extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, 16 unsigned long, int); 17 18 /* Architecture code defines this if there are other possible ELF 19 * machine types, e.g. on bi-arch capable hardware. */ 20 #ifndef vmcore_elf_check_arch_cross 21 #define vmcore_elf_check_arch_cross(x) 0 22 #endif 23 24 #define vmcore_elf_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x)) 25 26 /* 27 * is_kdump_kernel() checks whether this kernel is booting after a panic of 28 * previous kernel or not. This is determined by checking if previous kernel 29 * has passed the elf core header address on command line. 30 * 31 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will 32 * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of 33 * previous kernel. 34 */ 35 is_kdump_kernel(void)36static inline int is_kdump_kernel(void) 37 { 38 return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0; 39 } 40 41 /* is_vmcore_usable() checks if the kernel is booting after a panic and 42 * the vmcore region is usable. 43 * 44 * This makes use of the fact that due to alignment -2ULL is not 45 * a valid pointer, much in the vain of IS_ERR(), except 46 * dealing directly with an unsigned long long rather than a pointer. 47 */ 48 is_vmcore_usable(void)49static inline int is_vmcore_usable(void) 50 { 51 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; 52 } 53 54 /* vmcore_unusable() marks the vmcore as unusable, 55 * without disturbing the logic of is_kdump_kernel() 56 */ 57 vmcore_unusable(void)58static inline void vmcore_unusable(void) 59 { 60 if (is_kdump_kernel()) 61 elfcorehdr_addr = ELFCORE_ADDR_ERR; 62 } 63 #else /* !CONFIG_CRASH_DUMP */ is_kdump_kernel(void)64static inline int is_kdump_kernel(void) { return 0; } 65 #endif /* CONFIG_CRASH_DUMP */ 66 67 extern unsigned long saved_max_pfn; 68 #endif /* LINUX_CRASHDUMP_H */ 69