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Diffstat (limited to 'arch/x86/mm/kaslr.c')
-rw-r--r--arch/x86/mm/kaslr.c29
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();