68 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			68 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef LINUX_CRASH_DUMP_H
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#define LINUX_CRASH_DUMP_H
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#ifdef CONFIG_CRASH_DUMP
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#include <linux/kexec.h>
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#include <linux/device.h>
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#include <linux/proc_fs.h>
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#define ELFCORE_ADDR_MAX	(-1ULL)
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#define ELFCORE_ADDR_ERR	(-2ULL)
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extern unsigned long long elfcorehdr_addr;
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extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
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						unsigned long, int);
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/* Architecture code defines this if there are other possible ELF
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 * machine types, e.g. on bi-arch capable hardware. */
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#ifndef vmcore_elf_check_arch_cross
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#define vmcore_elf_check_arch_cross(x) 0
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#endif
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#define vmcore_elf_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
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/*
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 * is_kdump_kernel() checks whether this kernel is booting after a panic of
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 * previous kernel or not. This is determined by checking if previous kernel
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 * has passed the elf core header address on command line.
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 *
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 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
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 * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of
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 * previous kernel.
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 */
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static inline int is_kdump_kernel(void)
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{
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	return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0;
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}
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/* is_vmcore_usable() checks if the kernel is booting after a panic and
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 * the vmcore region is usable.
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 *
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 * This makes use of the fact that due to alignment -2ULL is not
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 * a valid pointer, much in the vain of IS_ERR(), except
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 * dealing directly with an unsigned long long rather than a pointer.
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 */
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static inline int is_vmcore_usable(void)
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{
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	return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
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}
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/* vmcore_unusable() marks the vmcore as unusable,
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 * without disturbing the logic of is_kdump_kernel()
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 */
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static inline void vmcore_unusable(void)
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{
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	if (is_kdump_kernel())
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		elfcorehdr_addr = ELFCORE_ADDR_ERR;
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}
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#else /* !CONFIG_CRASH_DUMP */
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static inline int is_kdump_kernel(void) { return 0; }
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#endif /* CONFIG_CRASH_DUMP */
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extern unsigned long saved_max_pfn;
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#endif /* LINUX_CRASHDUMP_H */
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