3ab8352137
This patch provides an enhancement to kexec/kdump. It implements the
following features:
- Backup/restore memory used by the original kernel before/after
kexec.
- Save/restore CPU state before/after kexec.
The features of this patch can be used as a general method to call program in
physical mode (paging turning off). This can be used to call BIOS code under
Linux.
kexec-tools needs to be patched to support kexec jump. The patches and
the precompiled kexec can be download from the following URL:
source: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-src_git_kh10.tar.bz2
patches: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-patches_git_kh10.tar.bz2
binary: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec_git_kh10
Usage example of calling some physical mode code and return:
1. Compile and install patched kernel with following options selected:
CONFIG_X86_32=y
CONFIG_KEXEC=y
CONFIG_PM=y
CONFIG_KEXEC_JUMP=y
2. Build patched kexec-tool or download the pre-built one.
3. Build some physical mode executable named such as "phy_mode"
4. Boot kernel compiled in step 1.
5. Load physical mode executable with /sbin/kexec. The shell command
line can be as follow:
/sbin/kexec --load-preserve-context --args-none phy_mode
6. Call physical mode executable with following shell command line:
/sbin/kexec -e
Implementation point:
To support jumping without reserving memory. One shadow backup page (source
page) is allocated for each page used by kexeced code image (destination
page). When do kexec_load, the image of kexeced code is loaded into source
pages, and before executing, the destination pages and the source pages are
swapped, so the contents of destination pages are backupped. Before jumping
to the kexeced code image and after jumping back to the original kernel, the
destination pages and the source pages are swapped too.
C ABI (calling convention) is used as communication protocol between
kernel and called code.
A flag named KEXEC_PRESERVE_CONTEXT for sys_kexec_load is added to
indicate that the loaded kernel image is used for jumping back.
Now, only the i386 architecture is supported.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
213 lines
6.4 KiB
C
213 lines
6.4 KiB
C
#ifndef LINUX_KEXEC_H
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#define LINUX_KEXEC_H
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#ifdef CONFIG_KEXEC
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#include <linux/types.h>
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#include <linux/list.h>
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#include <linux/linkage.h>
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#include <linux/compat.h>
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#include <linux/ioport.h>
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#include <linux/elfcore.h>
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#include <linux/elf.h>
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#include <asm/kexec.h>
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/* Verify architecture specific macros are defined */
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#ifndef KEXEC_SOURCE_MEMORY_LIMIT
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#error KEXEC_SOURCE_MEMORY_LIMIT not defined
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#endif
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#ifndef KEXEC_DESTINATION_MEMORY_LIMIT
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#error KEXEC_DESTINATION_MEMORY_LIMIT not defined
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#endif
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#ifndef KEXEC_CONTROL_MEMORY_LIMIT
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#error KEXEC_CONTROL_MEMORY_LIMIT not defined
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#endif
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#ifndef KEXEC_CONTROL_CODE_SIZE
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#error KEXEC_CONTROL_CODE_SIZE not defined
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#endif
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#ifndef KEXEC_ARCH
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#error KEXEC_ARCH not defined
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#endif
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#define KEXEC_NOTE_HEAD_BYTES ALIGN(sizeof(struct elf_note), 4)
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#define KEXEC_CORE_NOTE_NAME "CORE"
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#define KEXEC_CORE_NOTE_NAME_BYTES ALIGN(sizeof(KEXEC_CORE_NOTE_NAME), 4)
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#define KEXEC_CORE_NOTE_DESC_BYTES ALIGN(sizeof(struct elf_prstatus), 4)
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/*
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* The per-cpu notes area is a list of notes terminated by a "NULL"
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* note header. For kdump, the code in vmcore.c runs in the context
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* of the second kernel to combine them into one note.
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*/
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#define KEXEC_NOTE_BYTES ( (KEXEC_NOTE_HEAD_BYTES * 2) + \
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KEXEC_CORE_NOTE_NAME_BYTES + \
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KEXEC_CORE_NOTE_DESC_BYTES )
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/*
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* This structure is used to hold the arguments that are used when loading
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* kernel binaries.
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*/
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typedef unsigned long kimage_entry_t;
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#define IND_DESTINATION 0x1
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#define IND_INDIRECTION 0x2
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#define IND_DONE 0x4
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#define IND_SOURCE 0x8
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#define KEXEC_SEGMENT_MAX 16
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struct kexec_segment {
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void __user *buf;
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size_t bufsz;
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unsigned long mem; /* User space sees this as a (void *) ... */
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size_t memsz;
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};
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#ifdef CONFIG_COMPAT
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struct compat_kexec_segment {
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compat_uptr_t buf;
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compat_size_t bufsz;
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compat_ulong_t mem; /* User space sees this as a (void *) ... */
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compat_size_t memsz;
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};
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#endif
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struct kimage {
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kimage_entry_t head;
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kimage_entry_t *entry;
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kimage_entry_t *last_entry;
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unsigned long destination;
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unsigned long start;
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struct page *control_code_page;
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struct page *swap_page;
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unsigned long nr_segments;
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struct kexec_segment segment[KEXEC_SEGMENT_MAX];
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struct list_head control_pages;
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struct list_head dest_pages;
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struct list_head unuseable_pages;
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/* Address of next control page to allocate for crash kernels. */
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unsigned long control_page;
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/* Flags to indicate special processing */
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unsigned int type : 1;
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#define KEXEC_TYPE_DEFAULT 0
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#define KEXEC_TYPE_CRASH 1
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unsigned int preserve_context : 1;
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};
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/* kexec interface functions */
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extern void machine_kexec(struct kimage *image);
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extern int machine_kexec_prepare(struct kimage *image);
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extern void machine_kexec_cleanup(struct kimage *image);
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extern asmlinkage long sys_kexec_load(unsigned long entry,
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unsigned long nr_segments,
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struct kexec_segment __user *segments,
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unsigned long flags);
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extern int kernel_kexec(void);
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#ifdef CONFIG_COMPAT
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extern asmlinkage long compat_sys_kexec_load(unsigned long entry,
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unsigned long nr_segments,
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struct compat_kexec_segment __user *segments,
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unsigned long flags);
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#endif
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extern struct page *kimage_alloc_control_pages(struct kimage *image,
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unsigned int order);
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extern void crash_kexec(struct pt_regs *);
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int kexec_should_crash(struct task_struct *);
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void crash_save_cpu(struct pt_regs *regs, int cpu);
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void crash_save_vmcoreinfo(void);
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void arch_crash_save_vmcoreinfo(void);
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void vmcoreinfo_append_str(const char *fmt, ...)
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__attribute__ ((format (printf, 1, 2)));
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unsigned long paddr_vmcoreinfo_note(void);
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#define VMCOREINFO_OSRELEASE(name) \
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vmcoreinfo_append_str("OSRELEASE=%s\n", #name)
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#define VMCOREINFO_PAGESIZE(value) \
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vmcoreinfo_append_str("PAGESIZE=%ld\n", value)
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#define VMCOREINFO_SYMBOL(name) \
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vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)&name)
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#define VMCOREINFO_SIZE(name) \
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vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \
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(unsigned long)sizeof(name))
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#define VMCOREINFO_STRUCT_SIZE(name) \
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vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \
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(unsigned long)sizeof(struct name))
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#define VMCOREINFO_OFFSET(name, field) \
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vmcoreinfo_append_str("OFFSET(%s.%s)=%lu\n", #name, #field, \
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(unsigned long)offsetof(struct name, field))
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#define VMCOREINFO_LENGTH(name, value) \
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vmcoreinfo_append_str("LENGTH(%s)=%lu\n", #name, (unsigned long)value)
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#define VMCOREINFO_NUMBER(name) \
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vmcoreinfo_append_str("NUMBER(%s)=%ld\n", #name, (long)name)
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#define VMCOREINFO_CONFIG(name) \
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vmcoreinfo_append_str("CONFIG_%s=y\n", #name)
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extern struct kimage *kexec_image;
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extern struct kimage *kexec_crash_image;
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#ifndef kexec_flush_icache_page
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#define kexec_flush_icache_page(page)
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#endif
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#define KEXEC_ON_CRASH 0x00000001
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#define KEXEC_PRESERVE_CONTEXT 0x00000002
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#define KEXEC_ARCH_MASK 0xffff0000
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/* These values match the ELF architecture values.
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* Unless there is a good reason that should continue to be the case.
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*/
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#define KEXEC_ARCH_DEFAULT ( 0 << 16)
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#define KEXEC_ARCH_386 ( 3 << 16)
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#define KEXEC_ARCH_X86_64 (62 << 16)
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#define KEXEC_ARCH_PPC (20 << 16)
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#define KEXEC_ARCH_PPC64 (21 << 16)
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#define KEXEC_ARCH_IA_64 (50 << 16)
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#define KEXEC_ARCH_ARM (40 << 16)
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#define KEXEC_ARCH_S390 (22 << 16)
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#define KEXEC_ARCH_SH (42 << 16)
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#define KEXEC_ARCH_MIPS_LE (10 << 16)
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#define KEXEC_ARCH_MIPS ( 8 << 16)
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/* List of defined/legal kexec flags */
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#ifndef CONFIG_KEXEC_JUMP
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#define KEXEC_FLAGS KEXEC_ON_CRASH
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#else
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#define KEXEC_FLAGS (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT)
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#endif
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#define VMCOREINFO_BYTES (4096)
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#define VMCOREINFO_NOTE_NAME "VMCOREINFO"
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#define VMCOREINFO_NOTE_NAME_BYTES ALIGN(sizeof(VMCOREINFO_NOTE_NAME), 4)
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#define VMCOREINFO_NOTE_SIZE (KEXEC_NOTE_HEAD_BYTES*2 + VMCOREINFO_BYTES \
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+ VMCOREINFO_NOTE_NAME_BYTES)
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/* Location of a reserved region to hold the crash kernel.
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*/
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extern struct resource crashk_res;
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typedef u32 note_buf_t[KEXEC_NOTE_BYTES/4];
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extern note_buf_t *crash_notes;
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extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
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extern size_t vmcoreinfo_size;
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extern size_t vmcoreinfo_max_size;
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int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
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unsigned long long *crash_size, unsigned long long *crash_base);
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#else /* !CONFIG_KEXEC */
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struct pt_regs;
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struct task_struct;
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static inline void crash_kexec(struct pt_regs *regs) { }
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static inline int kexec_should_crash(struct task_struct *p) { return 0; }
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#endif /* CONFIG_KEXEC */
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#endif /* LINUX_KEXEC_H */
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