148 строки
5.0 KiB
C
148 строки
5.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef LINUX_CRASH_DUMP_H
|
|
#define LINUX_CRASH_DUMP_H
|
|
|
|
#include <linux/kexec.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/elf.h>
|
|
#include <linux/pgtable.h>
|
|
#include <uapi/linux/vmcore.h>
|
|
|
|
/* For IS_ENABLED(CONFIG_CRASH_DUMP) */
|
|
#define ELFCORE_ADDR_MAX (-1ULL)
|
|
#define ELFCORE_ADDR_ERR (-2ULL)
|
|
|
|
extern unsigned long long elfcorehdr_addr;
|
|
extern unsigned long long elfcorehdr_size;
|
|
|
|
#ifdef CONFIG_CRASH_DUMP
|
|
extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size);
|
|
extern void elfcorehdr_free(unsigned long long addr);
|
|
extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos);
|
|
extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos);
|
|
extern int remap_oldmem_pfn_range(struct vm_area_struct *vma,
|
|
unsigned long from, unsigned long pfn,
|
|
unsigned long size, pgprot_t prot);
|
|
|
|
ssize_t copy_oldmem_page(struct iov_iter *i, unsigned long pfn, size_t csize,
|
|
unsigned long offset);
|
|
ssize_t copy_oldmem_page_encrypted(struct iov_iter *iter, unsigned long pfn,
|
|
size_t csize, unsigned long offset);
|
|
|
|
void vmcore_cleanup(void);
|
|
|
|
/* Architecture code defines this if there are other possible ELF
|
|
* machine types, e.g. on bi-arch capable hardware. */
|
|
#ifndef vmcore_elf_check_arch_cross
|
|
#define vmcore_elf_check_arch_cross(x) 0
|
|
#endif
|
|
|
|
/*
|
|
* Architecture code can redefine this if there are any special checks
|
|
* needed for 32-bit ELF or 64-bit ELF vmcores. In case of 32-bit
|
|
* only architecture, vmcore_elf64_check_arch can be set to zero.
|
|
*/
|
|
#ifndef vmcore_elf32_check_arch
|
|
#define vmcore_elf32_check_arch(x) elf_check_arch(x)
|
|
#endif
|
|
|
|
#ifndef vmcore_elf64_check_arch
|
|
#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
|
|
#endif
|
|
|
|
/*
|
|
* is_kdump_kernel() checks whether this kernel is booting after a panic of
|
|
* previous kernel or not. This is determined by checking if previous kernel
|
|
* has passed the elf core header address on command line.
|
|
*
|
|
* This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
|
|
* return true if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic
|
|
* of previous kernel.
|
|
*/
|
|
|
|
static inline bool is_kdump_kernel(void)
|
|
{
|
|
return elfcorehdr_addr != ELFCORE_ADDR_MAX;
|
|
}
|
|
|
|
/* is_vmcore_usable() checks if the kernel is booting after a panic and
|
|
* the vmcore region is usable.
|
|
*
|
|
* This makes use of the fact that due to alignment -2ULL is not
|
|
* a valid pointer, much in the vain of IS_ERR(), except
|
|
* dealing directly with an unsigned long long rather than a pointer.
|
|
*/
|
|
|
|
static inline int is_vmcore_usable(void)
|
|
{
|
|
return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
|
|
}
|
|
|
|
/* vmcore_unusable() marks the vmcore as unusable,
|
|
* without disturbing the logic of is_kdump_kernel()
|
|
*/
|
|
|
|
static inline void vmcore_unusable(void)
|
|
{
|
|
if (is_kdump_kernel())
|
|
elfcorehdr_addr = ELFCORE_ADDR_ERR;
|
|
}
|
|
|
|
/**
|
|
* struct vmcore_cb - driver callbacks for /proc/vmcore handling
|
|
* @pfn_is_ram: check whether a PFN really is RAM and should be accessed when
|
|
* reading the vmcore. Will return "true" if it is RAM or if the
|
|
* callback cannot tell. If any callback returns "false", it's not
|
|
* RAM and the page must not be accessed; zeroes should be
|
|
* indicated in the vmcore instead. For example, a ballooned page
|
|
* contains no data and reading from such a page will cause high
|
|
* load in the hypervisor.
|
|
* @next: List head to manage registered callbacks internally; initialized by
|
|
* register_vmcore_cb().
|
|
*
|
|
* vmcore callbacks allow drivers managing physical memory ranges to
|
|
* coordinate with vmcore handling code, for example, to prevent accessing
|
|
* physical memory ranges that should not be accessed when reading the vmcore,
|
|
* although included in the vmcore header as memory ranges to dump.
|
|
*/
|
|
struct vmcore_cb {
|
|
bool (*pfn_is_ram)(struct vmcore_cb *cb, unsigned long pfn);
|
|
struct list_head next;
|
|
};
|
|
extern void register_vmcore_cb(struct vmcore_cb *cb);
|
|
extern void unregister_vmcore_cb(struct vmcore_cb *cb);
|
|
|
|
#else /* !CONFIG_CRASH_DUMP */
|
|
static inline bool is_kdump_kernel(void) { return false; }
|
|
#endif /* CONFIG_CRASH_DUMP */
|
|
|
|
/* Device Dump information to be filled by drivers */
|
|
struct vmcoredd_data {
|
|
char dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Unique name of the dump */
|
|
unsigned int size; /* Size of the dump */
|
|
/* Driver's registered callback to be invoked to collect dump */
|
|
int (*vmcoredd_callback)(struct vmcoredd_data *data, void *buf);
|
|
};
|
|
|
|
#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
|
|
int vmcore_add_device_dump(struct vmcoredd_data *data);
|
|
#else
|
|
static inline int vmcore_add_device_dump(struct vmcoredd_data *data)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
|
|
|
|
#ifdef CONFIG_PROC_VMCORE
|
|
ssize_t read_from_oldmem(struct iov_iter *iter, size_t count,
|
|
u64 *ppos, bool encrypted);
|
|
#else
|
|
static inline ssize_t read_from_oldmem(struct iov_iter *iter, size_t count,
|
|
u64 *ppos, bool encrypted)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
#endif /* CONFIG_PROC_VMCORE */
|
|
|
|
#endif /* LINUX_CRASHDUMP_H */
|