diff options
| author | Kees Cook <keescook@chromium.org> | 2016-04-18 09:42:14 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-04-19 10:30:51 +0200 |
| commit | 7de828dfe607013546ece7ce25aa9839e8f93a66 (patch) | |
| tree | b95b70071b3cf1dcc0b653b964528ffa5d250b0e /arch/x86/boot | |
| parent | c04028813221c2d39a4f368586795ac4466d311c (diff) | |
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: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Kees 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: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/boot')
| -rw-r--r-- | arch/x86/boot/compressed/kaslr.c | 13 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/misc.c | 2 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/misc.h | 4 |
3 files changed, 15 insertions, 4 deletions
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index a51ec841c9b9..9e03190d00ad 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -1,3 +1,14 @@ +/* + * 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) diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 0d69e809673a..ad8c01ac2885 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -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); diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 1f750a516580..9887e0d4aaeb 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -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) |