diff options
| author | Borislav Petkov <bp@suse.de> | 2015-04-01 12:49:52 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-04-03 15:26:15 +0200 |
| commit | 78cac48c0434c82e860fade3cd0420a7a4adbb08 (patch) | |
| tree | 76e1afefb1a0f9baad05487738de9f1b4a126aa7 /arch/x86/kernel | |
| parent | 47091e3c5b072daca29a15d2a3caf40359b0d140 (diff) | |
| download | linux-78cac48c0434c82e860fade3cd0420a7a4adbb08.tar.bz2 | |
x86/mm/KASLR: Propagate KASLR status to kernel proper
Commit:
e2b32e678513 ("x86, kaslr: randomize module base load address")
made module base address randomization unconditional and didn't regard
disabled KKASLR due to CONFIG_HIBERNATION and command line option
"nokaslr". For more info see (now reverted) commit:
f47233c2d34f ("x86/mm/ASLR: Propagate base load address calculation")
In order to propagate KASLR status to kernel proper, we need a single bit
in boot_params.hdr.loadflags and we've chosen bit 1 thus leaving the
top-down allocated bits for bits supposed to be used by the bootloader.
Originally-From: Jiri Kosina <jkosina@suse.cz>
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/module.c | 11 | ||||
| -rw-r--r-- | arch/x86/kernel/setup.c | 13 |
2 files changed, 11 insertions, 13 deletions
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; } |