linux/arch/x86/boot/compressed/misc.h
Baoquan He 8eabf42ae5 x86/boot/KASLR: Fix kexec crash due to 'virt_addr' calculation bug
Kernel text KASLR is separated into physical address and virtual
address randomization. And for virtual address randomization, we
only randomiza to get an offset between 16M and KERNEL_IMAGE_SIZE.
So the initial value of 'virt_addr' should be LOAD_PHYSICAL_ADDR,
but not the original kernel loading address 'output'.

The bug will cause kernel boot failure if kernel is loaded at a different
position than the address, 16M, which is decided at compiled time.
Kexec/kdump is such practical case.

To fix it, just assign LOAD_PHYSICAL_ADDR to virt_addr as initial
value.

Tested-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 8391c73 ("x86/KASLR: Randomize virtual address separately")
Link: http://lkml.kernel.org/r/1498567146-11990-3-git-send-email-bhe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-30 08:53:14 +02:00

112 lines
2.6 KiB
C

#ifndef BOOT_COMPRESSED_MISC_H
#define BOOT_COMPRESSED_MISC_H
/*
* Special hack: we have to be careful, because no indirections are allowed here,
* and paravirt_ops is a kind of one. As it will only run in baremetal anyway,
* we just keep it from happening. (This list needs to be extended when new
* paravirt and debugging variants are added.)
*/
#undef CONFIG_PARAVIRT
#undef CONFIG_PARAVIRT_SPINLOCKS
#undef CONFIG_KASAN
#include <linux/linkage.h>
#include <linux/screen_info.h>
#include <linux/elf.h>
#include <linux/io.h>
#include <asm/page.h>
#include <asm/boot.h>
#include <asm/bootparam.h>
#include <asm/bootparam_utils.h>
#define BOOT_BOOT_H
#include "../ctype.h"
#ifdef CONFIG_X86_64
#define memptr long
#else
#define memptr unsigned
#endif
/* misc.c */
extern memptr free_mem_ptr;
extern memptr free_mem_end_ptr;
extern struct boot_params *boot_params;
void __putstr(const char *s);
void __puthex(unsigned long value);
#define error_putstr(__x) __putstr(__x)
#define error_puthex(__x) __puthex(__x)
#ifdef CONFIG_X86_VERBOSE_BOOTUP
#define debug_putstr(__x) __putstr(__x)
#define debug_puthex(__x) __puthex(__x)
#define debug_putaddr(__x) { \
debug_putstr(#__x ": 0x"); \
debug_puthex((unsigned long)(__x)); \
debug_putstr("\n"); \
}
#else
static inline void debug_putstr(const char *s)
{ }
static inline void debug_puthex(const char *s)
{ }
#define debug_putaddr(x) /* */
#endif
#if CONFIG_EARLY_PRINTK || CONFIG_RANDOMIZE_BASE
/* cmdline.c */
int cmdline_find_option(const char *option, char *buffer, int bufsize);
int cmdline_find_option_bool(const char *option);
#endif
#if CONFIG_RANDOMIZE_BASE
/* kaslr.c */
void choose_random_location(unsigned long input,
unsigned long input_size,
unsigned long *output,
unsigned long output_size,
unsigned long *virt_addr);
/* cpuflags.c */
bool has_cpuflag(int flag);
#else
static inline void choose_random_location(unsigned long input,
unsigned long input_size,
unsigned long *output,
unsigned long output_size,
unsigned long *virt_addr)
{
}
#endif
#ifdef CONFIG_X86_64
void initialize_identity_maps(void);
void add_identity_map(unsigned long start, unsigned long size);
void finalize_identity_maps(void);
extern unsigned char _pgtable[];
#else
static inline void initialize_identity_maps(void)
{ }
static inline void add_identity_map(unsigned long start, unsigned long size)
{ }
static inline void finalize_identity_maps(void)
{ }
#endif
#ifdef CONFIG_EARLY_PRINTK
/* early_serial_console.c */
extern int early_serial_base;
void console_init(void);
#else
static const int early_serial_base;
static inline void console_init(void)
{ }
#endif
#endif