Commit dc009d92 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Linus Torvalds
Browse files

[PATCH] kexec: add kexec syscalls 



This patch introduces the architecture independent implementation the
sys_kexec_load, the compat_sys_kexec_load system calls.

Kexec on panic support has been integrated into the core patch and is
relatively clean.

In addition the hopefully architecture independent option
crashkernel=size@location has been docuemented.  It's purpose is to reserve
space for the panic kernel to live, and where no DMA transfer will ever be
setup to access.

Signed-off-by: default avatarEric Biederman <ebiederm@xmission.com>
Signed-off-by: default avatarAlexander Nyberg <alexn@telia.com>
Signed-off-by: default avatarAdrian Bunk <bunk@stusta.de>
Signed-off-by: default avatarVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent d0537508

Documentation/kernel-parameters.txt

+4 −0
Original line number Diff line number Diff line
@@ -358,6 +358,10 @@ running once the system is up. 
	cpia_pp=	[HW,PPT]

			Format: { parport<nr> | auto | none }



	crashkernel=nn[KMG]@ss[KMG]

			[KNL] Reserve a chunk of physical memory to

			hold a kernel to switch to with kexec on panic.



	cs4232=		[HW,OSS]

			Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>

MAINTAINERS

+10 −0
Original line number Diff line number Diff line
@@ -1330,6 +1330,16 @@ M: rml@novell.com 
L:	linux-kernel@vger.kernel.org

S:	Maintained



KEXEC

P:	Eric Biederman

P:	Randy Dunlap

M:	ebiederm@xmission.com

M:	rddunlap@osdl.org

W:	http://www.xmission.com/~ebiederm/files/kexec/

L:	linux-kernel@vger.kernel.org

L:	fastboot@osdl.org

S:	Maintained



LANMEDIA WAN CARD DRIVER

P:	Andrew Stanley-Jones

M:	asj@lanmedia.com

include/linux/kexec.h

0 → 100644
+127 −0
Original line number Diff line number Diff line 
#ifndef LINUX_KEXEC_H

#define LINUX_KEXEC_H



#ifdef CONFIG_KEXEC

#include <linux/types.h>

#include <linux/list.h>

#include <linux/linkage.h>

#include <linux/compat.h>

#include <asm/kexec.h>



/* Verify architecture specific macros are defined */



#ifndef KEXEC_SOURCE_MEMORY_LIMIT

#error KEXEC_SOURCE_MEMORY_LIMIT not defined

#endif



#ifndef KEXEC_DESTINATION_MEMORY_LIMIT

#error KEXEC_DESTINATION_MEMORY_LIMIT not defined

#endif



#ifndef KEXEC_CONTROL_MEMORY_LIMIT

#error KEXEC_CONTROL_MEMORY_LIMIT not defined

#endif



#ifndef KEXEC_CONTROL_CODE_SIZE

#error KEXEC_CONTROL_CODE_SIZE not defined

#endif



#ifndef KEXEC_ARCH

#error KEXEC_ARCH not defined

#endif



/*

 * This structure is used to hold the arguments that are used when loading

 * kernel binaries.

 */



typedef unsigned long kimage_entry_t;

#define IND_DESTINATION  0x1

#define IND_INDIRECTION  0x2

#define IND_DONE         0x4

#define IND_SOURCE       0x8



#define KEXEC_SEGMENT_MAX 8

struct kexec_segment {

	void __user *buf;

	size_t bufsz;

	unsigned long mem;	/* User space sees this as a (void *) ... */

	size_t memsz;

};



#ifdef CONFIG_COMPAT

struct compat_kexec_segment {

	compat_uptr_t buf;

	compat_size_t bufsz;

	compat_ulong_t mem;	/* User space sees this as a (void *) ... */

	compat_size_t memsz;

};

#endif



struct kimage {

	kimage_entry_t head;

	kimage_entry_t *entry;

	kimage_entry_t *last_entry;



	unsigned long destination;



	unsigned long start;

	struct page *control_code_page;



	unsigned long nr_segments;

	struct kexec_segment segment[KEXEC_SEGMENT_MAX];



	struct list_head control_pages;

	struct list_head dest_pages;

	struct list_head unuseable_pages;



	/* Address of next control page to allocate for crash kernels. */

	unsigned long control_page;



	/* Flags to indicate special processing */

	unsigned int type : 1;

#define KEXEC_TYPE_DEFAULT 0

#define KEXEC_TYPE_CRASH   1

};







/* kexec interface functions */

extern NORET_TYPE void machine_kexec(struct kimage *image) ATTRIB_NORET;

extern int machine_kexec_prepare(struct kimage *image);

extern void machine_kexec_cleanup(struct kimage *image);

extern asmlinkage long sys_kexec_load(unsigned long entry,

	unsigned long nr_segments, struct kexec_segment __user *segments,

	unsigned long flags);

#ifdef CONFIG_COMPAT

extern asmlinkage long compat_sys_kexec_load(unsigned long entry,

	unsigned long nr_segments, struct compat_kexec_segment __user *segments,

	unsigned long flags);

#endif

extern struct page *kimage_alloc_control_pages(struct kimage *image, unsigned int order);

extern void crash_kexec(void);

extern struct kimage *kexec_image;



#define KEXEC_ON_CRASH  0x00000001

#define KEXEC_ARCH_MASK 0xffff0000



/* These values match the ELF architecture values.

 * Unless there is a good reason that should continue to be the case.

 */

#define KEXEC_ARCH_DEFAULT ( 0 << 16)

#define KEXEC_ARCH_386     ( 3 << 16)

#define KEXEC_ARCH_X86_64  (62 << 16)

#define KEXEC_ARCH_PPC     (20 << 16)

#define KEXEC_ARCH_PPC64   (21 << 16)

#define KEXEC_ARCH_IA_64   (50 << 16)



#define KEXEC_FLAGS    (KEXEC_ON_CRASH)  /* List of defined/legal kexec flags */



/* Location of a reserved region to hold the crash kernel.

 */

extern struct resource crashk_res;



#else /* !CONFIG_KEXEC */

static inline void crash_kexec(void) { }

#endif /* CONFIG_KEXEC */

#endif /* LINUX_KEXEC_H */

include/linux/reboot.h

+3 −0
Original line number Diff line number Diff line
@@ -51,6 +51,9 @@ extern void machine_restart(char *cmd); 
extern void machine_halt(void);

extern void machine_power_off(void);



extern void machine_shutdown(void);

extern void machine_crash_shutdown(void);



#endif



#endif /* _LINUX_REBOOT_H */

include/linux/syscalls.h

+3 −2
Original line number Diff line number Diff line
@@ -159,8 +159,9 @@ asmlinkage long sys_shutdown(int, int); 
asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd,

				void __user *arg);

asmlinkage long sys_restart_syscall(void);

asmlinkage long sys_kexec_load(void *entry, unsigned long nr_segments,

			struct kexec_segment *segments, unsigned long flags);

asmlinkage long sys_kexec_load(unsigned long entry,

	unsigned long nr_segments, struct kexec_segment __user *segments,

	unsigned long flags);



asmlinkage long sys_exit(int error_code);

asmlinkage void sys_exit_group(int error_code);