Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4fa5662b authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Ingo Molnar
Browse files

x86/mm: Initialize 'page_offset_base' at boot-time 



For 4- and 5-level paging we have different 'page_offset_base'.
Let's initialize it at boot-time accordingly to machine capability.

We also have to split __PAGE_OFFSET_BASE into two constants -- for 4-
and 5-level paging.

Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180214182542.69302-4-kirill.shutemov@linux.intel.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent b16e770b

arch/x86/include/asm/page_64_types.h

+3 −6
Original line number Diff line number Diff line
@@ -37,16 +37,13 @@ 
 * hypervisor to fit.  Choosing 16 slots here is arbitrary, but it's

 * what Xen requires.

 */

#ifdef CONFIG_X86_5LEVEL

#define __PAGE_OFFSET_BASE      _AC(0xff10000000000000, UL)

#else

#define __PAGE_OFFSET_BASE      _AC(0xffff880000000000, UL)

#endif

#define __PAGE_OFFSET_BASE_L5	_AC(0xff10000000000000, UL)

#define __PAGE_OFFSET_BASE_L4	_AC(0xffff880000000000, UL)



#ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT

#define __PAGE_OFFSET           page_offset_base

#else

#define __PAGE_OFFSET           __PAGE_OFFSET_BASE

#define __PAGE_OFFSET           __PAGE_OFFSET_BASE_L4

#endif /* CONFIG_DYNAMIC_MEMORY_LAYOUT */



#define __START_KERNEL_map	_AC(0xffffffff80000000, UL)

arch/x86/kernel/head64.c

+9 −4
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ EXPORT_SYMBOL(ptrs_per_p4d); 
#endif



#ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT

unsigned long page_offset_base __ro_after_init = __PAGE_OFFSET_BASE;

unsigned long page_offset_base __ro_after_init = __PAGE_OFFSET_BASE_L4;

EXPORT_SYMBOL(page_offset_base);

unsigned long vmalloc_base __ro_after_init = __VMALLOC_BASE;

EXPORT_SYMBOL(vmalloc_base);
@@ -64,6 +64,11 @@ static void __head *fixup_pointer(void *ptr, unsigned long physaddr) 
	return ptr - (void *)_text + (void *)physaddr;

}



static unsigned long __head *fixup_long(void *ptr, unsigned long physaddr)

{

	return fixup_pointer(ptr, physaddr);

}



#ifdef CONFIG_X86_5LEVEL

static unsigned int __head *fixup_int(void *ptr, unsigned long physaddr)

{
@@ -81,6 +86,7 @@ static void __head check_la57_support(unsigned long physaddr) 
	*fixup_int(&pgtable_l5_enabled, physaddr) = 1;

	*fixup_int(&pgdir_shift, physaddr) = 48;

	*fixup_int(&ptrs_per_p4d, physaddr) = 512;

	*fixup_long(&page_offset_base, physaddr) = __PAGE_OFFSET_BASE_L5;

}

#else

static void __head check_la57_support(unsigned long physaddr) {}
@@ -89,7 +95,7 @@ static void __head check_la57_support(unsigned long physaddr) {} 
unsigned long __head __startup_64(unsigned long physaddr,

				  struct boot_params *bp)

{

	unsigned long load_delta, *p;

	unsigned long load_delta;

	unsigned long pgtable_flags;

	pgdval_t *pgd;

	p4dval_t *p4d;
@@ -196,8 +202,7 @@ unsigned long __head __startup_64(unsigned long physaddr, 
	 * Fixup phys_base - remove the memory encryption mask to obtain

	 * the true physical address.

	 */

	p = fixup_pointer(&phys_base, physaddr);

	*p += load_delta - sme_get_me_mask();

	*fixup_long(&phys_base, physaddr) += load_delta - sme_get_me_mask();



	/* Encrypt the kernel and related (if SME is active) */

	sme_encrypt_kernel(bp);

arch/x86/kernel/head_64.S

+1 −1
Original line number Diff line number Diff line
@@ -41,7 +41,7 @@ 
#define pud_index(x)	(((x) >> PUD_SHIFT) & (PTRS_PER_PUD-1))



#if defined(CONFIG_XEN_PV) || defined(CONFIG_XEN_PVH)

PGD_PAGE_OFFSET = pgd_index(__PAGE_OFFSET_BASE)

PGD_PAGE_OFFSET = pgd_index(__PAGE_OFFSET_BASE_L4)

PGD_START_KERNEL = pgd_index(__START_KERNEL_map)

#endif

L3_START_KERNEL = pud_index(__START_KERNEL_map)

arch/x86/mm/kaslr.c

+4 −4
Original line number Diff line number Diff line
@@ -34,13 +34,10 @@ 
#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;



/*
@@ -76,11 +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