x86/mm: Enable KASLR for vmalloc memory regions

Add vmalloc to the list of randomized memory regions.

The vmalloc memory region contains the allocation made through the vmalloc()
API. The allocations are done sequentially to prevent fragmentation and
each allocation address can easily be deduced especially from boot.

Signed-off-by: Thomas Garnier <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Cc: Alexander Kuleshov <[email protected]>
Cc: Alexander Popov <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Dave Young <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Jan Beulich <[email protected]>
Cc: Joerg Roedel <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Lv Zheng <[email protected]>
Cc: Mark Salter <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Matt Fleming <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephen Smalley <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Xiao Guangrong <[email protected]>
Cc: Yinghai Lu <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

3 files changed, 16 insertions, 5 deletions

diff --git a/arch/x86/include/asm/kaslr.h b/arch/x86/include/asm/kaslr.h
index 62b1b815a83a..2674ee3de748 100644
--- a/arch/x86/include/asm/kaslr.h
+++ b/arch/x86/include/asm/kaslr.h
@@ -5,6 +5,7 @@ unsigned long kaslr_get_random_long(const char *purpose);
 
 #ifdef CONFIG_RANDOMIZE_MEMORY
 extern unsigned long page_offset_base;
+extern unsigned long vmalloc_base;
 
 void kernel_randomize_memory(void);
 #else
diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h
index e6844dfb4471..6fdef9eef2d5 100644
--- a/arch/x86/include/asm/pgtable_64_types.h
+++ b/arch/x86/include/asm/pgtable_64_types.h
@@ -5,6 +5,7 @@
 
 #ifndef __ASSEMBLY__
 #include <linux/types.h>
+#include <asm/kaslr.h>
 
 /*
  * These are used to make use of C type-checking..
@@ -53,10 +54,16 @@ typedef struct { pteval_t pte; } pte_t;
 #define PGDIR_MASK	(~(PGDIR_SIZE - 1))
 
 /* See Documentation/x86/x86_64/mm.txt for a description of the memory map. */
-#define MAXMEM		 _AC(__AC(1, UL) << MAX_PHYSMEM_BITS, UL)
-#define VMALLOC_START    _AC(0xffffc90000000000, UL)
-#define VMALLOC_END      _AC(0xffffe8ffffffffff, UL)
-#define VMEMMAP_START	 _AC(0xffffea0000000000, UL)
+#define MAXMEM		_AC(__AC(1, UL) << MAX_PHYSMEM_BITS, UL)
+#define VMALLOC_SIZE_TB	_AC(32, UL)
+#define __VMALLOC_BASE	_AC(0xffffc90000000000, UL)
+#define VMEMMAP_START	_AC(0xffffea0000000000, UL)
+#ifdef CONFIG_RANDOMIZE_MEMORY
+#define VMALLOC_START	vmalloc_base
+#else
+#define VMALLOC_START	__VMALLOC_BASE
+#endif /* CONFIG_RANDOMIZE_MEMORY */
+#define VMALLOC_END	(VMALLOC_START + _AC((VMALLOC_SIZE_TB << 40) - 1, UL))
 #define MODULES_VADDR    (__START_KERNEL_map + KERNEL_IMAGE_SIZE)
 #define MODULES_END      _AC(0xffffffffff000000, UL)
 #define MODULES_LEN   (MODULES_END - MODULES_VADDR)
diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c
index 609ecf2b37ed..c939cfe1b516 100644
--- a/arch/x86/mm/kaslr.c
+++ b/arch/x86/mm/kaslr.c
@@ -44,11 +44,13 @@
  * ensure that this order is correct and won't be changed.
  */
 static const unsigned long vaddr_start = __PAGE_OFFSET_BASE;
-static const unsigned long vaddr_end = VMALLOC_START;
+static const unsigned long vaddr_end = VMEMMAP_START;
 
 /* 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);
 
 /*
  * Memory regions randomized by KASLR (except modules that use a separate logic
@@ -60,6 +62,7 @@ static __initdata struct kaslr_memory_region {
 	unsigned long size_tb;
 } kaslr_regions[] = {
 	{ &page_offset_base, 64/* Maximum */ },
+	{ &vmalloc_base, VMALLOC_SIZE_TB },
 };
 
 /* Get size in bytes used by the memory region */