kernel-ark/include/linux/kexec.h
Haren Myneni 9c15e852a5 [PATCH] kexec: fix in free initrd when overlapped with crashkernel region
It is possible that the reserved crashkernel region can be overlapped with
initrd since the bootloader sets the initrd location.  When the initrd
region is freed, the second kernel memory will not be contiguous.  The
Kexec_load can cause an oops since there is no contiguous memory to write
the second kernel or this memory could be used in the first kernel itself
and may not be part of the dump.  For example, on powerpc, the initrd is
located at 36MB and the crashkernel starts at 32MB.  The kexec_load caused
panic since writing into non-allocated memory (after 36MB).  We could see
the similar issue even on other archs.

One possibility is to move the initrd outside of crashkernel region.  But,
the initrd region will be freed anyway before the system is up.  This patch
fixes this issue and frees only regions that are not part of crashkernel
memory in case overlaps.

Signed-off-by: Haren Myneni <haren@us.ibm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-10 08:13:12 -08:00

140 lines
3.6 KiB
C

#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 <linux/ioport.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 16
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(struct pt_regs *);
int kexec_should_crash(struct task_struct *);
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_ARCH_S390 (22 << 16)
#define KEXEC_ARCH_SH (42 << 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;
typedef u32 note_buf_t[MAX_NOTE_BYTES/4];
extern note_buf_t *crash_notes;
#else /* !CONFIG_KEXEC */
struct pt_regs;
struct task_struct;
static inline void crash_kexec(struct pt_regs *regs) { }
static inline int kexec_should_crash(struct task_struct *p) { return 0; }
#endif /* CONFIG_KEXEC */
#endif /* LINUX_KEXEC_H */