diff options
| -rw-r--r-- | Documentation/x86/boot.txt | 6 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/aslr.c | 5 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/misc.c | 5 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/misc.h | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/setup.h | 5 | ||||
| -rw-r--r-- | arch/x86/include/uapi/asm/bootparam.h | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/module.c | 11 | ||||
| -rw-r--r-- | arch/x86/kernel/setup.c | 13 |
8 files changed, 35 insertions, 17 deletions
diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt index a75e3adaa39d..88b85899d309 100644 --- a/Documentation/x86/boot.txt +++ b/Documentation/x86/boot.txt @@ -406,6 +406,12 @@ Protocol: 2.00+ - If 0, the protected-mode code is loaded at 0x10000. - If 1, the protected-mode code is loaded at 0x100000. + Bit 1 (kernel internal): ALSR_FLAG + - Used internally by the compressed kernel to communicate + KASLR status to kernel proper. + If 1, KASLR enabled. + If 0, KASLR disabled. + Bit 5 (write): QUIET_FLAG - If 0, print early messages. - If 1, suppress early messages. diff --git a/arch/x86/boot/compressed/aslr.c b/arch/x86/boot/compressed/aslr.c index bb1376381985..d7b1f655b3ef 100644 --- a/arch/x86/boot/compressed/aslr.c +++ b/arch/x86/boot/compressed/aslr.c @@ -295,7 +295,8 @@ static unsigned long find_random_addr(unsigned long minimum, return slots_fetch_random(); } -unsigned char *choose_kernel_location(unsigned char *input, +unsigned char *choose_kernel_location(struct boot_params *boot_params, + unsigned char *input, unsigned long input_size, unsigned char *output, unsigned long output_size) @@ -315,6 +316,8 @@ unsigned char *choose_kernel_location(unsigned char *input, } #endif + boot_params->hdr.loadflags |= KASLR_FLAG; + /* Record the various known unsafe memory ranges. */ mem_avoid_init((unsigned long)input, input_size, (unsigned long)output, output_size); diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index a950864a64da..a107b935e22f 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -377,6 +377,9 @@ asmlinkage __visible void *decompress_kernel(void *rmode, memptr heap, real_mode = rmode; + /* Clear it for solely in-kernel use */ + real_mode->hdr.loadflags &= ~KASLR_FLAG; + sanitize_boot_params(real_mode); if (real_mode->screen_info.orig_video_mode == 7) { @@ -401,7 +404,7 @@ 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); diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 04477d68403f..89dd0d78013a 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -57,7 +57,8 @@ 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 *boot_params, + unsigned char *input, unsigned long input_size, unsigned char *output, unsigned long output_size); @@ -65,7 +66,8 @@ 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 *boot_params, + unsigned char *input, unsigned long input_size, unsigned char *output, unsigned long output_size) diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h index ff4e7b236e21..f69e06b283fb 100644 --- a/arch/x86/include/asm/setup.h +++ b/arch/x86/include/asm/setup.h @@ -66,6 +66,11 @@ static inline void x86_ce4100_early_setup(void) { } */ extern struct boot_params boot_params; +static inline bool kaslr_enabled(void) +{ + return !!(boot_params.hdr.loadflags & KASLR_FLAG); +} + /* * Do NOT EVER look at the BIOS memory size location. * It does not work on many machines. diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h index 225b0988043a..ab456dc233b5 100644 --- a/arch/x86/include/uapi/asm/bootparam.h +++ b/arch/x86/include/uapi/asm/bootparam.h @@ -15,6 +15,7 @@ /* loadflags */ #define LOADED_HIGH (1<<0) +#define KASLR_FLAG (1<<1) #define QUIET_FLAG (1<<5) #define KEEP_SEGMENTS (1<<6) #define CAN_USE_HEAP (1<<7) diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c index d1ac80b72c72..005c03e93fc5 100644 --- a/arch/x86/kernel/module.c +++ b/arch/x86/kernel/module.c @@ -33,6 +33,7 @@ #include <asm/page.h> #include <asm/pgtable.h> +#include <asm/setup.h> #if 0 #define DEBUGP(fmt, ...) \ @@ -47,21 +48,13 @@ do { \ #ifdef CONFIG_RANDOMIZE_BASE static unsigned long module_load_offset; -static int randomize_modules = 1; /* Mutex protects the module_load_offset. */ static DEFINE_MUTEX(module_kaslr_mutex); -static int __init parse_nokaslr(char *p) -{ - randomize_modules = 0; - return 0; -} -early_param("nokaslr", parse_nokaslr); - static unsigned long int get_module_load_offset(void) { - if (randomize_modules) { + if (kaslr_enabled()) { mutex_lock(&module_kaslr_mutex); /* * Calculate the module_load_offset the first time this diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 0a2421cca01f..014466b152b5 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -832,10 +832,15 @@ static void __init trim_low_memory_range(void) static int dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p) { - pr_emerg("Kernel Offset: 0x%lx from 0x%lx " - "(relocation range: 0x%lx-0x%lx)\n", - (unsigned long)&_text - __START_KERNEL, __START_KERNEL, - __START_KERNEL_map, MODULES_VADDR-1); + if (kaslr_enabled()) { + pr_emerg("Kernel Offset: 0x%lx from 0x%lx (relocation range: 0x%lx-0x%lx)\n", + (unsigned long)&_text - __START_KERNEL, + __START_KERNEL, + __START_KERNEL_map, + MODULES_VADDR-1); + } else { + pr_emerg("Kernel Offset: disabled\n"); + } return 0; } |