diff options
Diffstat (limited to 'arch/x86/mm/kaslr.c')
| -rw-r--r-- | arch/x86/mm/kaslr.c | 29 |
1 files changed, 12 insertions, 17 deletions
diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c index aedebd2ebf1e..615cc03ced84 100644 --- a/arch/x86/mm/kaslr.c +++ b/arch/x86/mm/kaslr.c @@ -34,23 +34,12 @@ #define TB_SHIFT 40 /* - * Virtual address start and end range for randomization. - * * The end address could depend on more configuration options to make the * highest amount of space for randomization available, but that's too hard * to keep straight and caused issues already. */ -static const unsigned long vaddr_start = __PAGE_OFFSET_BASE; static const unsigned long vaddr_end = CPU_ENTRY_AREA_BASE; -/* Default values */ -unsigned long page_offset_base = __PAGE_OFFSET_BASE; -EXPORT_SYMBOL(page_offset_base); -unsigned long vmalloc_base = __VMALLOC_BASE; -EXPORT_SYMBOL(vmalloc_base); -unsigned long vmemmap_base = __VMEMMAP_BASE; -EXPORT_SYMBOL(vmemmap_base); - /* * Memory regions randomized by KASLR (except modules that use a separate logic * earlier during boot). The list is ordered based on virtual addresses. This @@ -60,8 +49,8 @@ static __initdata struct kaslr_memory_region { unsigned long *base; unsigned long size_tb; } kaslr_regions[] = { - { &page_offset_base, 1 << (__PHYSICAL_MASK_SHIFT - TB_SHIFT) /* Maximum */ }, - { &vmalloc_base, VMALLOC_SIZE_TB }, + { &page_offset_base, 0 }, + { &vmalloc_base, 0 }, { &vmemmap_base, 1 }, }; @@ -84,11 +73,14 @@ static inline bool kaslr_memory_enabled(void) void __init kernel_randomize_memory(void) { size_t i; - unsigned long vaddr = vaddr_start; + unsigned long vaddr_start, vaddr; unsigned long rand, memory_tb; struct rnd_state rand_state; unsigned long remain_entropy; + vaddr_start = pgtable_l5_enabled ? __PAGE_OFFSET_BASE_L5 : __PAGE_OFFSET_BASE_L4; + vaddr = vaddr_start; + /* * These BUILD_BUG_ON checks ensure the memory layout is consistent * with the vaddr_start/vaddr_end variables. These checks are very @@ -101,6 +93,9 @@ void __init kernel_randomize_memory(void) if (!kaslr_memory_enabled()) return; + kaslr_regions[0].size_tb = 1 << (__PHYSICAL_MASK_SHIFT - TB_SHIFT); + kaslr_regions[1].size_tb = VMALLOC_SIZE_TB; + /* * Update Physical memory mapping to available and * add padding if needed (especially for memory hotplug support). @@ -129,7 +124,7 @@ void __init kernel_randomize_memory(void) */ entropy = remain_entropy / (ARRAY_SIZE(kaslr_regions) - i); prandom_bytes_state(&rand_state, &rand, sizeof(rand)); - if (IS_ENABLED(CONFIG_X86_5LEVEL)) + if (pgtable_l5_enabled) entropy = (rand % (entropy + 1)) & P4D_MASK; else entropy = (rand % (entropy + 1)) & PUD_MASK; @@ -141,7 +136,7 @@ void __init kernel_randomize_memory(void) * randomization alignment. */ vaddr += get_padding(&kaslr_regions[i]); - if (IS_ENABLED(CONFIG_X86_5LEVEL)) + if (pgtable_l5_enabled) vaddr = round_up(vaddr + 1, P4D_SIZE); else vaddr = round_up(vaddr + 1, PUD_SIZE); @@ -217,7 +212,7 @@ void __meminit init_trampoline(void) return; } - if (IS_ENABLED(CONFIG_X86_5LEVEL)) + if (pgtable_l5_enabled) init_trampoline_p4d(); else init_trampoline_pud(); |