linux/arch/x86/boot/compressed/cmdline.c
Kees Cook 8ab3820fd5 x86, kaslr: Return location from decompress_kernel
This allows decompress_kernel to return a new location for the kernel to
be relocated to. Additionally, enforces CONFIG_PHYSICAL_START as the
minimum relocation position when building with CONFIG_RELOCATABLE.

With CONFIG_RANDOMIZE_BASE set, the choose_kernel_location routine
will select a new location to decompress the kernel, though here it is
presently a no-op. The kernel command line option "nokaslr" is introduced
to bypass these routines.

Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1381450698-28710-3-git-send-email-keescook@chromium.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-10-13 03:12:07 -07:00

34 lines
772 B
C

#include "misc.h"
#if CONFIG_EARLY_PRINTK || CONFIG_RANDOMIZE_BASE
static unsigned long fs;
static inline void set_fs(unsigned long seg)
{
fs = seg << 4; /* shift it back */
}
typedef unsigned long addr_t;
static inline char rdfs8(addr_t addr)
{
return *((char *)(fs + addr));
}
#include "../cmdline.c"
static unsigned long get_cmd_line_ptr(void)
{
unsigned long cmd_line_ptr = real_mode->hdr.cmd_line_ptr;
cmd_line_ptr |= (u64)real_mode->ext_cmd_line_ptr << 32;
return cmd_line_ptr;
}
int cmdline_find_option(const char *option, char *buffer, int bufsize)
{
return __cmdline_find_option(get_cmd_line_ptr(), option, buffer, bufsize);
}
int cmdline_find_option_bool(const char *option)
{
return __cmdline_find_option_bool(get_cmd_line_ptr(), option);
}
#endif