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Diffstat (limited to 'arch/x86/boot/compressed/kaslr.c')
-rw-r--r--arch/x86/boot/compressed/kaslr.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index 8199a6187251..66e42a098d70 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -46,6 +46,12 @@
#define STATIC
#include <linux/decompress/mm.h>
+#ifdef CONFIG_X86_5LEVEL
+unsigned int pgtable_l5_enabled __ro_after_init;
+unsigned int pgdir_shift __ro_after_init = 39;
+unsigned int ptrs_per_p4d __ro_after_init = 1;
+#endif
+
extern unsigned long get_cmd_line_ptr(void);
/* Simplified build-specific string for starting entropy. */
@@ -723,6 +729,14 @@ void choose_random_location(unsigned long input,
return;
}
+#ifdef CONFIG_X86_5LEVEL
+ if (__read_cr4() & X86_CR4_LA57) {
+ pgtable_l5_enabled = 1;
+ pgdir_shift = 48;
+ ptrs_per_p4d = 512;
+ }
+#endif
+
boot_params->hdr.loadflags |= KASLR_FLAG;
/* Prepare to add new identity pagetables on demand. */