[apple/xnu.git] / san / kasan-x86_64.c

/*
 * Copyright (c) 2016 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#include <stdint.h>
#include <string.h>
#include <vm/vm_kern.h>
#include <vm/vm_map.h>
#include <kern/assert.h>
#include <i386/proc_reg.h>
#include <i386/machine_routines.h>
#include <kern/debug.h>
#include <mach/mach_vm.h>
#include <mach/vm_param.h>
#include <sys/param.h>
#include <i386/pmap.h>
#include <libkern/libkern.h>
#include <pexpert/i386/efi.h>
#include <pexpert/i386/boot.h>
#include <sys/queue.h>
#include <kasan.h>
#include <kasan_internal.h>
#include <vm/pmap.h>
#include <pexpert/i386/efi.h>
#include <pexpert/i386/boot.h>
#include <memintrinsics.h>

extern uint64_t *IdlePML4;
#define phys2virt(x) ((uintptr_t)(x) + physmap_base)

vm_offset_t shadow_pbase;
vm_offset_t shadow_ptop;
vm_offset_t shadow_pnext;
unsigned shadow_stolen_idx;

static vm_offset_t zero_superpage_phys;

typedef struct {
	unsigned int pml4   : 9;
	unsigned int pdpt   : 9;
	unsigned int pd     : 9;
	unsigned int pt     : 9;
	unsigned int offset : 12;
} split_addr_t;

static split_addr_t
split_address(vm_offset_t address)
{
	split_addr_t addr;

	addr.pml4   = (address >> 39) & 0x1ff;
	addr.pdpt   = (address >> 30) & 0x1ff;
	addr.pd     = (address >> 21) & 0x1ff;
	addr.pt     = (address >> 12) & 0x1ff;
	// addr.offset = address & PAGE_MASK;

	return addr;
}

static uintptr_t
alloc_page(void)
{
	if (shadow_pnext + I386_PGBYTES >= shadow_ptop) {
		panic("KASAN: OOM");
	}

	uintptr_t mem = shadow_pnext;
	shadow_pnext += I386_PGBYTES;
	shadow_pages_used++;

	return mem;
}

#define ROUND_SUPERPAGE(x) ((((uintptr_t)(x)) + I386_LPGBYTES - 1) & ~(I386_LPGMASK))

static uintptr_t
alloc_superpage(void)
{
	uintptr_t mem;
	shadow_pnext = ROUND_SUPERPAGE(shadow_pnext);
	assert((shadow_pnext & I386_LPGMASK) == 0);
	mem = shadow_pnext;
	shadow_pnext += I386_LPGBYTES;
	shadow_pages_used += I386_LPGBYTES / I386_PGBYTES;
	/* XXX: not accounting for superpage rounding */
	return mem;
}

static uintptr_t
alloc_page_zero(void)
{
	uintptr_t mem = alloc_page();
	bzero_phys(mem, I386_PGBYTES);
	return mem;
}

static void
kasan_map_shadow_superpage_zero(vm_offset_t address, vm_size_t size)
{
	address = vm_map_trunc_page(address, I386_LPGMASK);
	size = vm_map_round_page(size, I386_LPGMASK);

	vm_size_t j;
	for (j = 0; j < size; j += I386_LPGBYTES * 8) {
		vm_offset_t virt_shadow_target = (vm_offset_t)SHADOW_FOR_ADDRESS(address + j);

		split_addr_t addr = split_address(virt_shadow_target);
		assert(addr.pml4 >= KERNEL_KASAN_PML4_FIRST &&
		    addr.pml4 <= KERNEL_KASAN_PML4_LAST);

		uint64_t *L3;
		uint64_t *L2;
		uint64_t *L1;

		L3 = (uint64_t *)(IdlePML4[addr.pml4] & ~PAGE_MASK);
		if (L3 == NULL) {
			uintptr_t pmem = alloc_page_zero();
			L3 = (uint64_t *)phys2virt(pmem);
			IdlePML4[addr.pml4] = pmem
			    | INTEL_PTE_VALID
			    | INTEL_PTE_WRITE;
		} else {
			L3 = (uint64_t *)phys2virt(L3);
		}

		L2 = (uint64_t *)(L3[addr.pdpt] & ~PAGE_MASK);
		if (L2 == NULL) {
			uintptr_t pmem = alloc_page_zero();
			L2 = (uint64_t *)phys2virt(pmem);
			L3[addr.pdpt] = pmem
			    | INTEL_PTE_VALID
			    | INTEL_PTE_WRITE;
		} else {
			L2 = (uint64_t *)phys2virt(L2);
		}

		L1 = (uint64_t *)(L2[addr.pd] & ~PAGE_MASK);
		if (L1 == NULL) {
			L2[addr.pd] = (uint64_t)zero_superpage_phys
			    | INTEL_PTE_VALID
			    | INTEL_PTE_PS
			    | INTEL_PTE_NX;
		} else {
			panic("Unexpected shadow mapping, addr =  %lx, sz = %lu\n",
			    address, size);
		}

		/* adding a new entry, this is not strictly required */
		invlpg(virt_shadow_target);
	}
}

void
kasan_map_shadow(vm_offset_t address, vm_size_t size, bool is_zero)
{
	size = (size + 0x7UL) & ~0x7UL;
	vm_offset_t shadow_base = vm_map_trunc_page(SHADOW_FOR_ADDRESS(address), PAGE_MASK);
	vm_offset_t shadow_top = vm_map_round_page(SHADOW_FOR_ADDRESS(address + size), PAGE_MASK);

	assert((size & 0x7) == 0);

	for (; shadow_base < shadow_top; shadow_base += I386_PGBYTES) {
		split_addr_t addr = split_address(shadow_base);
		assert(addr.pml4 >= KERNEL_KASAN_PML4_FIRST &&
		    addr.pml4 <= KERNEL_KASAN_PML4_LAST);

		uint64_t *L3;
		uint64_t *L2;
		uint64_t *L1;
		uint64_t *pte;

		L3 = (uint64_t *)(IdlePML4[addr.pml4] & ~PAGE_MASK);
		if (L3 == NULL) {
			uintptr_t pmem = alloc_page_zero();
			L3 = (uint64_t *)phys2virt(pmem);
			IdlePML4[addr.pml4] = pmem
			    | INTEL_PTE_VALID
			    | INTEL_PTE_WRITE;
		} else {
			L3 = (uint64_t *)phys2virt(L3);
		}

		L2 = (uint64_t *)(L3[addr.pdpt] & ~PAGE_MASK);
		if (L2 == NULL) {
			uintptr_t pmem = alloc_page_zero();
			L2 = (uint64_t *)phys2virt(pmem);
			L3[addr.pdpt] = pmem
			    | INTEL_PTE_VALID
			    | INTEL_PTE_WRITE;
		} else {
			L2 = (uint64_t *)phys2virt(L2);
		}

		uint64_t pde = L2[addr.pd];
		if ((pde & (INTEL_PTE_VALID | INTEL_PTE_PS)) == (INTEL_PTE_VALID | INTEL_PTE_PS)) {
			/* Already mapped as a superpage */
			continue;
		}

		L1 = (uint64_t *)(pde & ~PAGE_MASK);
		if (L1 == NULL) {
			uintptr_t pmem = alloc_page_zero();
			L1 = (uint64_t *)phys2virt(pmem);
			L2[addr.pd] = pmem
			    | INTEL_PTE_VALID
			    | INTEL_PTE_WRITE;
		} else {
			L1 = (uint64_t *)phys2virt(L1);
		}

		pte = (uint64_t *)(L1[addr.pt] & ~PAGE_MASK);
		if (pte == NULL) {
			uint64_t newpte;
			if (is_zero) {
				newpte = (uint64_t)zero_superpage_phys;
			} else {
				newpte = (vm_offset_t)alloc_page_zero()
				    | INTEL_PTE_WRITE;
			}
			L1[addr.pt] = newpte
			    | INTEL_PTE_VALID
			    | INTEL_PTE_NX;

			/* adding a new entry, this is not strictly required */
			invlpg(shadow_base);
		}
	}
}

void
kasan_arch_init(void)
{
	__nosan_bzero((void *)phys2virt(zero_superpage_phys), I386_LPGBYTES);

	/* Map the physical aperture */
	kasan_map_shadow_superpage_zero(physmap_base, physmap_max - physmap_base);
}

/*
 * Steal some memory from EFI for the shadow map.
 */
void
kasan_reserve_memory(void *_args)
{
	boot_args *args = (boot_args *)_args;
	vm_address_t pbase = args->kaddr;
	vm_address_t ptop = args->kaddr + args->ksize;

	kernel_vbase = ml_static_ptovirt(pbase);
	kernel_vtop = ml_static_ptovirt(ptop);

	EfiMemoryRange *mptr, *mptr_tmp;
	unsigned int mcount;
	unsigned int msize;
	unsigned int i;
	unsigned long total_pages;
	unsigned long to_steal;

	mptr = (EfiMemoryRange *)ml_static_ptovirt((vm_offset_t)args->MemoryMap);
	msize = args->MemoryMapDescriptorSize;
	mcount = args->MemoryMapSize / msize;

	/* sum total physical memory */
	total_pages = 0;
	for (i = 0, mptr_tmp = mptr; i < mcount; i++, mptr_tmp = (EfiMemoryRange *)(((vm_offset_t)mptr_tmp) + msize)) {
		total_pages += mptr_tmp->NumberOfPages;
	}

	to_steal = (total_pages * STOLEN_MEM_PERCENT) / 100 + (STOLEN_MEM_BYTES / I386_PGBYTES);

	/* Search for a range large enough to steal from */
	for (i = 0, mptr_tmp = mptr; i < mcount; i++, mptr_tmp = (EfiMemoryRange *)(((vm_offset_t)mptr_tmp) + msize)) {
		ppnum_t base, top;
		base = (ppnum_t)(mptr_tmp->PhysicalStart >> I386_PGSHIFT);
		top = (ppnum_t)((mptr_tmp->PhysicalStart >> I386_PGSHIFT) + mptr_tmp->NumberOfPages - 1);

		if ((mptr_tmp->Type == kEfiConventionalMemory) && (mptr_tmp->NumberOfPages > to_steal)) {
			/* Found a region with sufficient space - steal from the end */
			mptr_tmp->NumberOfPages -= to_steal;

			shadow_pbase = mptr_tmp->PhysicalStart + (mptr_tmp->NumberOfPages << I386_PGSHIFT);
			shadow_ptop = shadow_pbase + (to_steal << I386_PGSHIFT);
			shadow_pnext = shadow_pbase;
			shadow_pages_total = to_steal;
			shadow_stolen_idx = i;

			/* Set aside a page of zeros we can use for dummy shadow mappings */
			zero_superpage_phys = alloc_superpage();

			return;
		}
	}

	panic("KASAN: could not reserve memory");
}

bool
kasan_is_shadow_mapped(uintptr_t shadowp)
{
	split_addr_t addr = split_address(shadowp);
	assert(addr.pml4 >= KERNEL_KASAN_PML4_FIRST &&
	    addr.pml4 <= KERNEL_KASAN_PML4_LAST);

	uint64_t *L3;
	uint64_t *L2;
	uint64_t *L1;

	L3 = (uint64_t *)(IdlePML4[addr.pml4] & ~PAGE_MASK);
	if (L3 == NULL) {
		return false;
	}
	L3 = (uint64_t *)phys2virt(L3);

	L2 = (uint64_t *)(L3[addr.pdpt] & ~PAGE_MASK);
	if (L2 == NULL) {
		return false;
	}
	L2 = (uint64_t *)phys2virt(L2);

	uint64_t pde = L2[addr.pd];
	if ((pde & (INTEL_PTE_VALID | INTEL_PTE_PS)) == (INTEL_PTE_VALID | INTEL_PTE_PS)) {
		/* mapped as superpage */
		return true;
	}
	L1 = (uint64_t *)(pde & ~PAGE_MASK);
	if (L1 == NULL) {
		return false;
	}
	L1 = (uint64_t *)phys2virt(L1);

	if (L1[addr.pt] & INTEL_PTE_VALID) {
		return true;
	}

	return false;
}
Commit	Line	Data
5ba3f43e A	1	/*
	2	* Copyright (c) 2016 Apple Inc. All rights reserved.
	3	*
	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
	27	*/
	28
	29	#include <stdint.h>
	30	#include <string.h>
	31	#include <vm/vm_kern.h>
	32	#include <vm/vm_map.h>
	33	#include <kern/assert.h>
	34	#include <i386/proc_reg.h>
	35	#include <i386/machine_routines.h>
	36	#include <kern/debug.h>
	37	#include <mach/mach_vm.h>
	38	#include <mach/vm_param.h>
0a7de745 A	39	#include <sys/param.h>
0a7de745 A	40	#include <i386/pmap.h>
5ba3f43e A	41	#include <libkern/libkern.h>
	42	#include <pexpert/i386/efi.h>
	43	#include <pexpert/i386/boot.h>
	44	#include <sys/queue.h>
	45	#include <kasan.h>
	46	#include <kasan_internal.h>
	47	#include <vm/pmap.h>
	48	#include <pexpert/i386/efi.h>
	49	#include <pexpert/i386/boot.h>
	50	#include <memintrinsics.h>
	51
	52	extern uint64_t *IdlePML4;
5ba3f43e A	53	#define phys2virt(x) ((uintptr_t)(x) + physmap_base)
5ba3f43e A	54
5ba3f43e A	55	vm_offset_t shadow_pbase;
	56	vm_offset_t shadow_ptop;
	57	vm_offset_t shadow_pnext;
	58	unsigned shadow_stolen_idx;
	59
	60	static vm_offset_t zero_superpage_phys;
	61
	62	typedef struct {
0a7de745 A	63	unsigned int pml4 : 9;
	64	unsigned int pdpt : 9;
	65	unsigned int pd : 9;
	66	unsigned int pt : 9;
	67	unsigned int offset : 12;
5ba3f43e A	68	} split_addr_t;
	69
	70	static split_addr_t
	71	split_address(vm_offset_t address)
	72	{
	73	split_addr_t addr;
	74
	75	addr.pml4 = (address >> 39) & 0x1ff;
	76	addr.pdpt = (address >> 30) & 0x1ff;
	77	addr.pd = (address >> 21) & 0x1ff;
	78	addr.pt = (address >> 12) & 0x1ff;
	79	// addr.offset = address & PAGE_MASK;
	80
	81	return addr;
	82	}
	83
	84	static uintptr_t
	85	alloc_page(void)
	86	{
	87	if (shadow_pnext + I386_PGBYTES >= shadow_ptop) {
	88	panic("KASAN: OOM");
	89	}
	90
	91	uintptr_t mem = shadow_pnext;
	92	shadow_pnext += I386_PGBYTES;
	93	shadow_pages_used++;
	94
	95	return mem;
	96	}
	97
	98	#define ROUND_SUPERPAGE(x) ((((uintptr_t)(x)) + I386_LPGBYTES - 1) & ~(I386_LPGMASK))
	99
	100	static uintptr_t
	101	alloc_superpage(void)
	102	{
	103	uintptr_t mem;
	104	shadow_pnext = ROUND_SUPERPAGE(shadow_pnext);
	105	assert((shadow_pnext & I386_LPGMASK) == 0);
	106	mem = shadow_pnext;
	107	shadow_pnext += I386_LPGBYTES;
	108	shadow_pages_used += I386_LPGBYTES / I386_PGBYTES;
	109	/* XXX: not accounting for superpage rounding */
	110	return mem;
	111	}
	112
	113	static uintptr_t
	114	alloc_page_zero(void)
	115	{
	116	uintptr_t mem = alloc_page();
	117	bzero_phys(mem, I386_PGBYTES);
	118	return mem;
	119	}
	120
	121	static void
	122	kasan_map_shadow_superpage_zero(vm_offset_t address, vm_size_t size)
	123	{
	124	address = vm_map_trunc_page(address, I386_LPGMASK);
	125	size = vm_map_round_page(size, I386_LPGMASK);
	126
	127	vm_size_t j;
	128	for (j = 0; j < size; j += I386_LPGBYTES * 8) {
5ba3f43e A	129	vm_offset_t virt_shadow_target = (vm_offset_t)SHADOW_FOR_ADDRESS(address + j);
	130
	131	split_addr_t addr = split_address(virt_shadow_target);
0a7de745 A	132	assert(addr.pml4 >= KERNEL_KASAN_PML4_FIRST &&
0a7de745 A	133	addr.pml4 <= KERNEL_KASAN_PML4_LAST);
5ba3f43e A	134
	135	uint64_t *L3;
	136	uint64_t *L2;
	137	uint64_t *L1;
	138
	139	L3 = (uint64_t *)(IdlePML4[addr.pml4] & ~PAGE_MASK);
	140	if (L3 == NULL) {
	141	uintptr_t pmem = alloc_page_zero();
	142	L3 = (uint64_t *)phys2virt(pmem);
	143	IdlePML4[addr.pml4] = pmem
0a7de745 A	144	\| INTEL_PTE_VALID
0a7de745 A	145	\| INTEL_PTE_WRITE;
5ba3f43e A	146	} else {
	147	L3 = (uint64_t *)phys2virt(L3);
	148	}
	149
	150	L2 = (uint64_t *)(L3[addr.pdpt] & ~PAGE_MASK);
	151	if (L2 == NULL) {
	152	uintptr_t pmem = alloc_page_zero();
	153	L2 = (uint64_t *)phys2virt(pmem);
	154	L3[addr.pdpt] = pmem
0a7de745 A	155	\| INTEL_PTE_VALID
0a7de745 A	156	\| INTEL_PTE_WRITE;
5ba3f43e A	157	} else {
	158	L2 = (uint64_t *)phys2virt(L2);
	159	}
	160
	161	L1 = (uint64_t *)(L2[addr.pd] & ~PAGE_MASK);
	162	if (L1 == NULL) {
	163	L2[addr.pd] = (uint64_t)zero_superpage_phys
0a7de745 A	164	\| INTEL_PTE_VALID
	165	\| INTEL_PTE_PS
	166	\| INTEL_PTE_NX;
5ba3f43e A	167	} else {
5ba3f43e A	168	panic("Unexpected shadow mapping, addr = %lx, sz = %lu\n",
0a7de745	169	address, size);
5ba3f43e A	170	}
	171
	172	/* adding a new entry, this is not strictly required */
	173	invlpg(virt_shadow_target);
	174	}
	175	}
	176
	177	void
	178	kasan_map_shadow(vm_offset_t address, vm_size_t size, bool is_zero)
	179	{
d9a64523	180	size = (size + 0x7UL) & ~0x7UL;
a39ff7e2 A	181	vm_offset_t shadow_base = vm_map_trunc_page(SHADOW_FOR_ADDRESS(address), PAGE_MASK);
a39ff7e2 A	182	vm_offset_t shadow_top = vm_map_round_page(SHADOW_FOR_ADDRESS(address + size), PAGE_MASK);
5ba3f43e	183
d9a64523 A	184	assert((size & 0x7) == 0);
d9a64523 A	185
a39ff7e2	186	for (; shadow_base < shadow_top; shadow_base += I386_PGBYTES) {
a39ff7e2	187	split_addr_t addr = split_address(shadow_base);
0a7de745 A	188	assert(addr.pml4 >= KERNEL_KASAN_PML4_FIRST &&
0a7de745 A	189	addr.pml4 <= KERNEL_KASAN_PML4_LAST);
5ba3f43e A	190
	191	uint64_t *L3;
	192	uint64_t *L2;
	193	uint64_t *L1;
	194	uint64_t *pte;
	195
	196	L3 = (uint64_t *)(IdlePML4[addr.pml4] & ~PAGE_MASK);
	197	if (L3 == NULL) {
	198	uintptr_t pmem = alloc_page_zero();
	199	L3 = (uint64_t *)phys2virt(pmem);
	200	IdlePML4[addr.pml4] = pmem
0a7de745 A	201	\| INTEL_PTE_VALID
0a7de745 A	202	\| INTEL_PTE_WRITE;
5ba3f43e A	203	} else {
	204	L3 = (uint64_t *)phys2virt(L3);
	205	}
	206
	207	L2 = (uint64_t *)(L3[addr.pdpt] & ~PAGE_MASK);
	208	if (L2 == NULL) {
	209	uintptr_t pmem = alloc_page_zero();
	210	L2 = (uint64_t *)phys2virt(pmem);
	211	L3[addr.pdpt] = pmem
0a7de745 A	212	\| INTEL_PTE_VALID
0a7de745 A	213	\| INTEL_PTE_WRITE;
5ba3f43e A	214	} else {
	215	L2 = (uint64_t *)phys2virt(L2);
	216	}
	217
	218	uint64_t pde = L2[addr.pd];
0a7de745	219	if ((pde & (INTEL_PTE_VALID \| INTEL_PTE_PS)) == (INTEL_PTE_VALID \| INTEL_PTE_PS)) {
5ba3f43e A	220	/* Already mapped as a superpage */
	221	continue;
	222	}
	223
	224	L1 = (uint64_t *)(pde & ~PAGE_MASK);
	225	if (L1 == NULL) {
	226	uintptr_t pmem = alloc_page_zero();
	227	L1 = (uint64_t *)phys2virt(pmem);
	228	L2[addr.pd] = pmem
0a7de745 A	229	\| INTEL_PTE_VALID
0a7de745 A	230	\| INTEL_PTE_WRITE;
5ba3f43e A	231	} else {
	232	L1 = (uint64_t *)phys2virt(L1);
	233	}
	234
	235	pte = (uint64_t *)(L1[addr.pt] & ~PAGE_MASK);
	236	if (pte == NULL) {
	237	uint64_t newpte;
	238	if (is_zero) {
	239	newpte = (uint64_t)zero_superpage_phys;
	240	} else {
	241	newpte = (vm_offset_t)alloc_page_zero()
0a7de745	242	\| INTEL_PTE_WRITE;
5ba3f43e A	243	}
5ba3f43e A	244	L1[addr.pt] = newpte
0a7de745 A	245	\| INTEL_PTE_VALID
0a7de745 A	246	\| INTEL_PTE_NX;
5ba3f43e	247
a39ff7e2 A	248	/* adding a new entry, this is not strictly required */
	249	invlpg(shadow_base);
	250	}
5ba3f43e A	251	}
	252	}
	253
	254	void
	255	kasan_arch_init(void)
	256	{
	257	__nosan_bzero((void *)phys2virt(zero_superpage_phys), I386_LPGBYTES);
	258
	259	/* Map the physical aperture */
	260	kasan_map_shadow_superpage_zero(physmap_base, physmap_max - physmap_base);
5ba3f43e A	261	}
	262
	263	/*
	264	* Steal some memory from EFI for the shadow map.
	265	*/
	266	void
	267	kasan_reserve_memory(void *_args)
	268	{
	269	boot_args args = (boot_args )_args;
	270	vm_address_t pbase = args->kaddr;
	271	vm_address_t ptop = args->kaddr + args->ksize;
	272
	273	kernel_vbase = ml_static_ptovirt(pbase);
	274	kernel_vtop = ml_static_ptovirt(ptop);
	275
	276	EfiMemoryRange mptr, mptr_tmp;
	277	unsigned int mcount;
	278	unsigned int msize;
	279	unsigned int i;
	280	unsigned long total_pages;
	281	unsigned long to_steal;
	282
	283	mptr = (EfiMemoryRange *)ml_static_ptovirt((vm_offset_t)args->MemoryMap);
	284	msize = args->MemoryMapDescriptorSize;
	285	mcount = args->MemoryMapSize / msize;
	286
	287	/* sum total physical memory */
	288	total_pages = 0;
	289	for (i = 0, mptr_tmp = mptr; i < mcount; i++, mptr_tmp = (EfiMemoryRange *)(((vm_offset_t)mptr_tmp) + msize)) {
	290	total_pages += mptr_tmp->NumberOfPages;
	291	}
	292
5c9f4661	293	to_steal = (total_pages * STOLEN_MEM_PERCENT) / 100 + (STOLEN_MEM_BYTES / I386_PGBYTES);
5ba3f43e A	294
	295	/* Search for a range large enough to steal from */
	296	for (i = 0, mptr_tmp = mptr; i < mcount; i++, mptr_tmp = (EfiMemoryRange *)(((vm_offset_t)mptr_tmp) + msize)) {
	297	ppnum_t base, top;
	298	base = (ppnum_t)(mptr_tmp->PhysicalStart >> I386_PGSHIFT);
	299	top = (ppnum_t)((mptr_tmp->PhysicalStart >> I386_PGSHIFT) + mptr_tmp->NumberOfPages - 1);
	300
	301	if ((mptr_tmp->Type == kEfiConventionalMemory) && (mptr_tmp->NumberOfPages > to_steal)) {
	302	/* Found a region with sufficient space - steal from the end */
	303	mptr_tmp->NumberOfPages -= to_steal;
	304
	305	shadow_pbase = mptr_tmp->PhysicalStart + (mptr_tmp->NumberOfPages << I386_PGSHIFT);
	306	shadow_ptop = shadow_pbase + (to_steal << I386_PGSHIFT);
	307	shadow_pnext = shadow_pbase;
	308	shadow_pages_total = to_steal;
	309	shadow_stolen_idx = i;
	310
	311	/* Set aside a page of zeros we can use for dummy shadow mappings */
	312	zero_superpage_phys = alloc_superpage();
	313
	314	return;
	315	}
	316	}
	317
	318	panic("KASAN: could not reserve memory");
	319	}
	320
a39ff7e2 A	321	bool
	322	kasan_is_shadow_mapped(uintptr_t shadowp)
	323	{
	324	split_addr_t addr = split_address(shadowp);
0a7de745 A	325	assert(addr.pml4 >= KERNEL_KASAN_PML4_FIRST &&
0a7de745 A	326	addr.pml4 <= KERNEL_KASAN_PML4_LAST);
a39ff7e2 A	327
	328	uint64_t *L3;
	329	uint64_t *L2;
	330	uint64_t *L1;
	331
	332	L3 = (uint64_t *)(IdlePML4[addr.pml4] & ~PAGE_MASK);
	333	if (L3 == NULL) {
	334	return false;
	335	}
	336	L3 = (uint64_t *)phys2virt(L3);
	337
	338	L2 = (uint64_t *)(L3[addr.pdpt] & ~PAGE_MASK);
	339	if (L2 == NULL) {
	340	return false;
	341	}
	342	L2 = (uint64_t *)phys2virt(L2);
	343
	344	uint64_t pde = L2[addr.pd];
0a7de745	345	if ((pde & (INTEL_PTE_VALID \| INTEL_PTE_PS)) == (INTEL_PTE_VALID \| INTEL_PTE_PS)) {
a39ff7e2 A	346	/* mapped as superpage */
	347	return true;
	348	}
	349	L1 = (uint64_t *)(pde & ~PAGE_MASK);
	350	if (L1 == NULL) {
	351	return false;
	352	}
	353	L1 = (uint64_t *)phys2virt(L1);
	354
	355	if (L1[addr.pt] & INTEL_PTE_VALID) {
	356	return true;
	357	}
	358
	359	return false;
	360	}