Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7de828df authored by Kees Cook's avatar Kees Cook Committed by Ingo Molnar
Browse files

x86/KASLR: Clarify purpose of kaslr.c 



The name "choose_kernel_location" isn't specific enough, and doesn't
describe the primary thing it does: choosing a random location. This
patch renames it to "choose_random_location", and clarifies the what
routines are contained in the kaslr.c source file.

Suggested-by: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: H.J. Lu <hjl.tools@gmail.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1460997735-24785-6-git-send-email-keescook@chromium.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent c0402881

arch/x86/boot/compressed/kaslr.c

+12 −1
Original line number Diff line number Diff line 
/*

 * kaslr.c

 *

 * This contains the routines needed to generate a reasonable level of

 * entropy to choose a randomized kernel base address offset in support

 * of Kernel Address Space Layout Randomization (KASLR). Additionally

 * handles walking the physical memory maps (and tracking memory regions

 * to avoid) in order to select a physical memory location that can

 * contain the entire properly aligned running kernel image.

 *

 */

#include "misc.h"



#include <asm/msr.h>
@@ -295,7 +306,7 @@ static unsigned long find_random_addr(unsigned long minimum, 
	return slots_fetch_random();

}



unsigned char *choose_kernel_location(unsigned char *input,

unsigned char *choose_random_location(unsigned char *input,

				      unsigned long input_size,

				      unsigned char *output,

				      unsigned long output_size)

arch/x86/boot/compressed/misc.c

+1 −1
Original line number Diff line number Diff line
@@ -431,7 +431,7 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, 
	 * the entire decompressed kernel plus relocation table, or the

	 * entire decompressed kernel plus .bss and .brk sections.

	 */

	output = choose_kernel_location(input_data, input_len, output,

	output = choose_random_location(input_data, input_len, output,

					output_len > run_size ? output_len

							      : run_size);

arch/x86/boot/compressed/misc.h

+2 −2
Original line number Diff line number Diff line
@@ -67,7 +67,7 @@ int cmdline_find_option_bool(const char *option); 


#if CONFIG_RANDOMIZE_BASE

/* kaslr.c */

unsigned char *choose_kernel_location(unsigned char *input,

unsigned char *choose_random_location(unsigned char *input,

				      unsigned long input_size,

				      unsigned char *output,

				      unsigned long output_size);
@@ -75,7 +75,7 @@ unsigned char *choose_kernel_location(unsigned char *input, 
bool has_cpuflag(int flag);

#else

static inline

unsigned char *choose_kernel_location(unsigned char *input,

unsigned char *choose_random_location(unsigned char *input,

				      unsigned long input_size,

				      unsigned char *output,

				      unsigned long output_size)