Files
linux/arch/x86/boot/compressed/misc.h
Baoquan He cc6b8fbcc6 x86/boot/KASLR: Fix kexec crash due to 'virt_addr' calculation bug
commit 8eabf42ae5 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-05 14:41:41 +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