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Commit a267b0a3 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

Merge branch 'tip-x86-kaslr' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp into x86/urgent 



Pull ASLR and kASLR fixes from Borislav Petkov:

  - Add a global flag announcing KASLR state so that relevant code can do
    informed decisions based on its setting. (Jiri Kosina)

  - Fix a stack randomization entropy decrease bug. (Hector Marco-Gisbert)

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parents ee408b42 4e7c22d4

arch/x86/boot/compressed/aslr.c

+33 −1
Original line number Diff line number Diff line
@@ -14,6 +14,13 @@ 
static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@"

		LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION;



struct kaslr_setup_data {

	__u64 next;

	__u32 type;

	__u32 len;

	__u8 data[1];

} kaslr_setup_data;



#define I8254_PORT_CONTROL	0x43

#define I8254_PORT_COUNTER0	0x40

#define I8254_CMD_READBACK	0xC0
@@ -295,7 +302,29 @@ static unsigned long find_random_addr(unsigned long minimum, 
	return slots_fetch_random();

}



unsigned char *choose_kernel_location(unsigned char *input,

static void add_kaslr_setup_data(struct boot_params *params, __u8 enabled)

{

	struct setup_data *data;



	kaslr_setup_data.type = SETUP_KASLR;

	kaslr_setup_data.len = 1;

	kaslr_setup_data.next = 0;

	kaslr_setup_data.data[0] = enabled;



	data = (struct setup_data *)(unsigned long)params->hdr.setup_data;



	while (data && data->next)

		data = (struct setup_data *)(unsigned long)data->next;



	if (data)

		data->next = (unsigned long)&kaslr_setup_data;

	else

		params->hdr.setup_data = (unsigned long)&kaslr_setup_data;



}



unsigned char *choose_kernel_location(struct boot_params *params,

				      unsigned char *input,

				      unsigned long input_size,

				      unsigned char *output,

				      unsigned long output_size)
@@ -306,14 +335,17 @@ unsigned char *choose_kernel_location(unsigned char *input, 
#ifdef CONFIG_HIBERNATION

	if (!cmdline_find_option_bool("kaslr")) {

		debug_putstr("KASLR disabled by default...\n");

		add_kaslr_setup_data(params, 0);

		goto out;

	}

#else

	if (cmdline_find_option_bool("nokaslr")) {

		debug_putstr("KASLR disabled by cmdline...\n");

		add_kaslr_setup_data(params, 0);

		goto out;

	}

#endif

	add_kaslr_setup_data(params, 1);



	/* Record the various known unsafe memory ranges. */

	mem_avoid_init((unsigned long)input, input_size,

arch/x86/boot/compressed/misc.c

+2 −1
Original line number Diff line number Diff line
@@ -401,7 +401,8 @@ asmlinkage __visible void *decompress_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_kernel_location(real_mode, input_data, input_len,

					output,

					output_len > run_size ? output_len

							      : run_size);

arch/x86/boot/compressed/misc.h

+4 −2
Original line number Diff line number Diff line
@@ -56,7 +56,8 @@ int cmdline_find_option_bool(const char *option); 


#if CONFIG_RANDOMIZE_BASE

/* aslr.c */

unsigned char *choose_kernel_location(unsigned char *input,

unsigned char *choose_kernel_location(struct boot_params *params,

				      unsigned char *input,

				      unsigned long input_size,

				      unsigned char *output,

				      unsigned long output_size);
@@ -64,7 +65,8 @@ 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_kernel_location(struct boot_params *params,

				      unsigned char *input,

				      unsigned long input_size,

				      unsigned char *output,

				      unsigned long output_size)

arch/x86/include/asm/page_types.h

+3 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 


#include <linux/const.h>

#include <linux/types.h>

#include <asm/bootparam.h>



/* PAGE_SHIFT determines the page size */

#define PAGE_SHIFT	12
@@ -51,6 +52,8 @@ extern int devmem_is_allowed(unsigned long pagenr); 
extern unsigned long max_low_pfn_mapped;

extern unsigned long max_pfn_mapped;



extern bool kaslr_enabled;



static inline phys_addr_t get_max_mapped(void)

{

	return (phys_addr_t)max_pfn_mapped << PAGE_SHIFT;

arch/x86/include/uapi/asm/bootparam.h

+1 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#define SETUP_DTB			2

#define SETUP_PCI			3

#define SETUP_EFI			4

#define SETUP_KASLR			5



/* ram_size flags */

#define RAMDISK_IMAGE_START_MASK	0x07FF