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>
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 674019d..9077af7 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -39,23 +39,38 @@
#endif
-#ifdef CONFIG_EARLY_PRINTK
-
+#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
+/* aslr.c */
+unsigned char *choose_kernel_location(unsigned char *input,
+ unsigned long input_size,
+ unsigned char *output,
+ unsigned long output_size);
+#else
+static inline
+unsigned char *choose_kernel_location(unsigned char *input,
+ unsigned long input_size,
+ unsigned char *output,
+ unsigned long output_size)
+{
+ return output;
+}
+#endif
+
+#ifdef CONFIG_EARLY_PRINTK
/* early_serial_console.c */
extern int early_serial_base;
void console_init(void);
-
#else
-
-/* early_serial_console.c */
static const int early_serial_base;
static inline void console_init(void)
{ }
-
#endif
#endif