src/Unix/vm_alloc.cpp

/*
 *  vm_alloc.cpp - Wrapper to various virtual memory allocation schemes
 *                 (supports mmap, vm_allocate or fallbacks to malloc)
 *
 *  Basilisk II (C) 1997-2008 Christian Bauer
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif

#ifdef HAVE_WIN32_VM
#define WIN32_LEAN_AND_MEAN /* avoid including junk */
#include <windows.h>
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include "vm_alloc.h"

#ifdef HAVE_MACH_VM
#ifndef HAVE_MACH_TASK_SELF
#ifdef HAVE_TASK_SELF
#define mach_task_self task_self
#else
#error "No task_self(), you lose."
#endif
#endif
#endif

#ifdef HAVE_WIN32_VM
/* Windows is either ILP32 or LLP64 */
typedef UINT_PTR vm_uintptr_t;
#else
/* Other systems are sane as they are either ILP32 or LP64 */
typedef unsigned long vm_uintptr_t;
#endif

/* We want MAP_32BIT, if available, for SheepShaver and BasiliskII
   because the emulated target is 32-bit and this helps to allocate
   memory so that branches could be resolved more easily (32-bit
   displacement to code in .text), on AMD64 for example.  */
#ifndef MAP_32BIT
#define MAP_32BIT 0
#endif
#ifndef MAP_ANON
#define MAP_ANON 0
#endif
#ifndef MAP_ANONYMOUS
#define MAP_ANONYMOUS 0
#endif

#define MAP_EXTRA_FLAGS (MAP_32BIT)

#ifdef HAVE_MMAP_VM
#if (defined(__linux__) && defined(__i386__)) || HAVE_LINKER_SCRIPT
/* Force a reasonnable address below 0x80000000 on x86 so that we
   don't get addresses above when the program is run on AMD64.
   NOTE: this is empirically determined on Linux/x86.  */
#define MAP_BASE        0x10000000
#else
#define MAP_BASE        0x00000000
#endif
static char * next_address = (char *)MAP_BASE;
#ifdef HAVE_MMAP_ANON
#define map_flags       (MAP_ANON | MAP_EXTRA_FLAGS)
#define zero_fd         -1
#else
#ifdef HAVE_MMAP_ANONYMOUS
#define map_flags       (MAP_ANONYMOUS | MAP_EXTRA_FLAGS)
#define zero_fd         -1
#else
#define map_flags       (MAP_EXTRA_FLAGS)
static int zero_fd      = -1;
#endif
#endif
#endif

/* Translate generic VM map flags to host values.  */

#ifdef HAVE_MMAP_VM
static int translate_map_flags(int vm_flags)
{
        int flags = 0;
        if (vm_flags & VM_MAP_SHARED)
                flags |= MAP_SHARED;
        if (vm_flags & VM_MAP_PRIVATE)
                flags |= MAP_PRIVATE;
        if (vm_flags & VM_MAP_FIXED)
                flags |= MAP_FIXED;
        if (vm_flags & VM_MAP_32BIT)
                flags |= MAP_32BIT;
        return flags;
}
#endif

/* Align ADDR and SIZE to 64K boundaries.  */

#ifdef HAVE_WIN32_VM
static inline LPVOID align_addr_segment(LPVOID addr)
{
        return (LPVOID)(((vm_uintptr_t)addr) & -((vm_uintptr_t)65536));
}

static inline DWORD align_size_segment(LPVOID addr, DWORD size)
{
        return size + ((vm_uintptr_t)addr - (vm_uintptr_t)align_addr_segment(addr));
}
#endif

/* Translate generic VM prot flags to host values.  */

#ifdef HAVE_WIN32_VM
static int translate_prot_flags(int prot_flags)
{
        int prot = PAGE_READWRITE;
        if (prot_flags == (VM_PAGE_EXECUTE | VM_PAGE_READ | VM_PAGE_WRITE))
                prot = PAGE_EXECUTE_READWRITE;
        else if (prot_flags == (VM_PAGE_EXECUTE | VM_PAGE_READ))
                prot = PAGE_EXECUTE_READ;
        else if (prot_flags == (VM_PAGE_READ | VM_PAGE_WRITE))
                prot = PAGE_READWRITE;
        else if (prot_flags == VM_PAGE_READ)
                prot = PAGE_READONLY;
        else if (prot_flags == 0)
                prot = PAGE_NOACCESS;
        return prot;
}
#endif

/* Initialize the VM system. Returns 0 if successful, -1 for errors.  */

int vm_init(void)
{
#ifdef HAVE_MMAP_VM
#ifndef zero_fd
        zero_fd = open("/dev/zero", O_RDWR);
        if (zero_fd < 0)
                return -1;
#endif
#endif
        return 0;
}

/* Deallocate all internal data used to wrap virtual memory allocators.  */

void vm_exit(void)
{
#ifdef HAVE_MMAP_VM
#ifndef zero_fd
        if (zero_fd != -1) {
                close(zero_fd);
                zero_fd = -1;
        }
#endif
#endif
}

/* Allocate zero-filled memory of SIZE bytes. The mapping is private
   and default protection bits are read / write. The return value
   is the actual mapping address chosen or VM_MAP_FAILED for errors.  */

void * vm_acquire(size_t size, int options)
{
        void * addr;

        // VM_MAP_FIXED are to be used with vm_acquire_fixed() only
        if (options & VM_MAP_FIXED)
                return VM_MAP_FAILED;

#ifdef HAVE_MACH_VM
        // vm_allocate() returns a zero-filled memory region
        if (vm_allocate(mach_task_self(), (vm_address_t *)&addr, size, TRUE) != KERN_SUCCESS)
                return VM_MAP_FAILED;
#else
#ifdef HAVE_MMAP_VM
        int fd = zero_fd;
        int the_map_flags = translate_map_flags(options) | map_flags;

        if ((addr = mmap((caddr_t)next_address, size, VM_PAGE_DEFAULT, the_map_flags, fd, 0)) == (void *)MAP_FAILED)
                return VM_MAP_FAILED;
        
        // Sanity checks for 64-bit platforms
        if (sizeof(void *) == 8 && (options & VM_MAP_32BIT) && !((char *)addr <= (char *)0xffffffff))
                return VM_MAP_FAILED;

        next_address = (char *)addr + size;
#else
#ifdef HAVE_WIN32_VM
        if ((addr = VirtualAlloc(NULL, size, MEM_RESERVE | MEM_COMMIT, PAGE_EXECUTE_READWRITE)) == NULL)
                return VM_MAP_FAILED;
#else
        if ((addr = calloc(size, 1)) == 0)
                return VM_MAP_FAILED;
        
        // Omit changes for protections because they are not supported in this mode
        return addr;
#endif
#endif
#endif

        // Explicitely protect the newly mapped region here because on some systems,
        // say MacOS X, mmap() doesn't honour the requested protection flags.
        if (vm_protect(addr, size, VM_PAGE_DEFAULT) != 0)
                return VM_MAP_FAILED;
        
        return addr;
}

/* Allocate zero-filled memory at exactly ADDR (which must be page-aligned).
   Retuns 0 if successful, -1 on errors.  */

int vm_acquire_fixed(void * addr, size_t size, int options)
{
        // Fixed mappings are required to be private
        if (options & VM_MAP_SHARED)
                return -1;

#ifdef HAVE_MACH_VM
        // vm_allocate() returns a zero-filled memory region
        if (vm_allocate(mach_task_self(), (vm_address_t *)&addr, size, 0) != KERN_SUCCESS)
                return -1;
#else
#ifdef HAVE_MMAP_VM
        int fd = zero_fd;
        int the_map_flags = translate_map_flags(options) | map_flags | MAP_FIXED;

        if (mmap((caddr_t)addr, size, VM_PAGE_DEFAULT, the_map_flags, fd, 0) == (void *)MAP_FAILED)
                return -1;
#else
#ifdef HAVE_WIN32_VM
        // Windows cannot allocate Low Memory
        if (addr == NULL)
                return -1;

        // Allocate a possibly offset region to align on 64K boundaries
        LPVOID req_addr = align_addr_segment(addr);
        DWORD  req_size = align_size_segment(addr, size);
        LPVOID ret_addr = VirtualAlloc(req_addr, req_size, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
        if (ret_addr != req_addr)
                return -1;
#else
        // Unsupported
        return -1;
#endif
#endif
#endif
        
        // Explicitely protect the newly mapped region here because on some systems,
        // say MacOS X, mmap() doesn't honour the requested protection flags.
        if (vm_protect(addr, size, VM_PAGE_DEFAULT) != 0)
                return -1;
        
        return 0;
}

/* Deallocate any mapping for the region starting at ADDR and extending
   LEN bytes. Returns 0 if successful, -1 on errors.  */

int vm_release(void * addr, size_t size)
{
        // Safety check: don't try to release memory that was not allocated
        if (addr == VM_MAP_FAILED)
                return 0;

#ifdef HAVE_MACH_VM
        if (vm_deallocate(mach_task_self(), (vm_address_t)addr, size) != KERN_SUCCESS)
                return -1;
#else
#ifdef HAVE_MMAP_VM
        if (munmap((caddr_t)addr, size) != 0)
                return -1;
#else
#ifdef HAVE_WIN32_VM
        if (VirtualFree(align_addr_segment(addr), 0, MEM_RELEASE) == 0)
                return -1;
#else
        free(addr);
#endif
#endif
#endif
        
        return 0;
}

/* Change the memory protection of the region starting at ADDR and
   extending LEN bytes to PROT. Returns 0 if successful, -1 for errors.  */

int vm_protect(void * addr, size_t size, int prot)
{
#ifdef HAVE_MACH_VM
        int ret_code = vm_protect(mach_task_self(), (vm_address_t)addr, size, 0, prot);
        return ret_code == KERN_SUCCESS ? 0 : -1;
#else
#ifdef HAVE_MMAP_VM
        int ret_code = mprotect((caddr_t)addr, size, prot);
        return ret_code == 0 ? 0 : -1;
#else
#ifdef HAVE_WIN32_VM
        DWORD old_prot;
        int ret_code = VirtualProtect(addr, size, translate_prot_flags(prot), &old_prot);
        return ret_code != 0 ? 0 : -1;
#else
        // Unsupported
        return -1;
#endif
#endif
#endif
}

/* Returns the size of a page.  */

int vm_get_page_size(void)
{
#ifdef HAVE_WIN32_VM
        static vm_uintptr_t page_size = 0;
        if (page_size == 0) {
                SYSTEM_INFO si;
                GetSystemInfo(&si);
                page_size = si.dwAllocationGranularity;
        }
        return page_size;
#else
        return getpagesize();
#endif
}

#ifdef CONFIGURE_TEST_VM_MAP
#include <stdlib.h>
#include <signal.h>

static void fault_handler(int sig)
{
        exit(1);
}

/* Tests covered here:
   - TEST_VM_PROT_* program slices actually succeeds when a crash occurs
   - TEST_VM_MAP_ANON* program slices succeeds when it could be compiled
*/
int main(void)
{
        vm_init();

        signal(SIGSEGV, fault_handler);
#ifdef SIGBUS
        signal(SIGBUS,  fault_handler);
#endif
        
#define page_align(address) ((char *)((vm_uintptr_t)(address) & -page_size))
        vm_uintptr_t page_size = vm_get_page_size();
        
        const int area_size = 6 * page_size;
        volatile char * area = (volatile char *) vm_acquire(area_size);
        volatile char * fault_address = area + (page_size * 7) / 2;

#if defined(TEST_VM_MMAP_ANON) || defined(TEST_VM_MMAP_ANONYMOUS)
        if (area == VM_MAP_FAILED)
                return 1;

        if (vm_release((char *)area, area_size) < 0)
                return 1;
        
        return 0;
#endif

#if defined(TEST_VM_PROT_NONE_READ) || defined(TEST_VM_PROT_NONE_WRITE)
        if (area == VM_MAP_FAILED)
                return 0;
        
        if (vm_protect(page_align(fault_address), page_size, VM_PAGE_NOACCESS) < 0)
                return 0;
#endif

#if defined(TEST_VM_PROT_RDWR_WRITE)
        if (area == VM_MAP_FAILED)
                return 1;
        
        if (vm_protect(page_align(fault_address), page_size, VM_PAGE_READ) < 0)
                return 1;
        
        if (vm_protect(page_align(fault_address), page_size, VM_PAGE_READ | VM_PAGE_WRITE) < 0)
                return 1;
#endif

#if defined(TEST_VM_PROT_READ_WRITE)
        if (vm_protect(page_align(fault_address), page_size, VM_PAGE_READ) < 0)
                return 0;
#endif

#if defined(TEST_VM_PROT_NONE_READ)
        // this should cause a core dump
        char foo = *fault_address;
        return 0;
#endif

#if defined(TEST_VM_PROT_NONE_WRITE) || defined(TEST_VM_PROT_READ_WRITE)
        // this should cause a core dump
        *fault_address = 'z';
        return 0;
#endif

#if defined(TEST_VM_PROT_RDWR_WRITE)
        // this should not cause a core dump
        *fault_address = 'z';
        return 0;
#endif
}
#endif
Revision:	1.28
Committed:	2008-01-12T21:43:02Z (16 years, 10 months ago) by gbeauche
Branch:	MAIN
Changes since 1.27:	+13 -5 lines
Log Message:	LLP64 fixes (64-bit Windows)
#	User	Rev	Content
1	gbeauche	1.1	/*
2			* vm_alloc.cpp - Wrapper to various virtual memory allocation schemes
3			* (supports mmap, vm_allocate or fallbacks to malloc)
4			*
5	gbeauche	1.27	* Basilisk II (C) 1997-2008 Christian Bauer
6	gbeauche	1.1	*
7			* This program is free software; you can redistribute it and/or modify
8			* it under the terms of the GNU General Public License as published by
9			* the Free Software Foundation; either version 2 of the License, or
10			* (at your option) any later version.
11			*
12			* This program is distributed in the hope that it will be useful,
13			* but WITHOUT ANY WARRANTY; without even the implied warranty of
14			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15			* GNU General Public License for more details.
16			*
17			* You should have received a copy of the GNU General Public License
18			* along with this program; if not, write to the Free Software
19			* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20			*/
21
22			#ifdef HAVE_CONFIG_H
23			#include "config.h"
24			#endif
25
26	gbeauche	1.13	#ifdef HAVE_FCNTL_H
27			#include <fcntl.h>
28			#endif
29
30	gbeauche	1.14	#ifdef HAVE_WIN32_VM
31			#define WIN32_LEAN_AND_MEAN /* avoid including junk */
32			#include <windows.h>
33			#endif
34
35	gbeauche	1.13	#include <stdio.h>
36	gbeauche	1.1	#include <stdlib.h>
37			#include <string.h>
38	gbeauche	1.13	#include <limits.h>
39	gbeauche	1.1	#include "vm_alloc.h"
40
41			#ifdef HAVE_MACH_VM
42			#ifndef HAVE_MACH_TASK_SELF
43			#ifdef HAVE_TASK_SELF
44			#define mach_task_self task_self
45			#else
46			#error "No task_self(), you lose."
47			#endif
48			#endif
49			#endif
50
51	gbeauche	1.28	#ifdef HAVE_WIN32_VM
52			/* Windows is either ILP32 or LLP64 */
53			typedef UINT_PTR vm_uintptr_t;
54			#else
55			/* Other systems are sane as they are either ILP32 or LP64 */
56			typedef unsigned long vm_uintptr_t;
57			#endif
58
59	gbeauche	1.9	/* We want MAP_32BIT, if available, for SheepShaver and BasiliskII
60			because the emulated target is 32-bit and this helps to allocate
61			memory so that branches could be resolved more easily (32-bit
62			displacement to code in .text), on AMD64 for example. */
63			#ifndef MAP_32BIT
64			#define MAP_32BIT 0
65			#endif
66	gbeauche	1.13	#ifndef MAP_ANON
67			#define MAP_ANON 0
68			#endif
69			#ifndef MAP_ANONYMOUS
70			#define MAP_ANONYMOUS 0
71			#endif
72	gbeauche	1.9
73			#define MAP_EXTRA_FLAGS (MAP_32BIT)
74
75	gbeauche	1.1	#ifdef HAVE_MMAP_VM
76	gbeauche	1.23	#if (defined(__linux__) && defined(__i386__)) \|\| HAVE_LINKER_SCRIPT
77	gbeauche	1.9	/* Force a reasonnable address below 0x80000000 on x86 so that we
78			don't get addresses above when the program is run on AMD64.
79			NOTE: this is empirically determined on Linux/x86. */
80			#define MAP_BASE 0x10000000
81			#else
82			#define MAP_BASE 0x00000000
83			#endif
84			static char * next_address = (char *)MAP_BASE;
85	gbeauche	1.1	#ifdef HAVE_MMAP_ANON
86	gbeauche	1.10	#define map_flags (MAP_ANON \| MAP_EXTRA_FLAGS)
87	gbeauche	1.1	#define zero_fd -1
88			#else
89			#ifdef HAVE_MMAP_ANONYMOUS
90	gbeauche	1.10	#define map_flags (MAP_ANONYMOUS \| MAP_EXTRA_FLAGS)
91	gbeauche	1.1	#define zero_fd -1
92			#else
93	gbeauche	1.10	#define map_flags (MAP_EXTRA_FLAGS)
94	gbeauche	1.1	static int zero_fd = -1;
95			#endif
96			#endif
97			#endif
98
99	gbeauche	1.10	/* Translate generic VM map flags to host values. */
100
101			#ifdef HAVE_MMAP_VM
102			static int translate_map_flags(int vm_flags)
103			{
104			int flags = 0;
105			if (vm_flags & VM_MAP_SHARED)
106			flags \|= MAP_SHARED;
107			if (vm_flags & VM_MAP_PRIVATE)
108			flags \|= MAP_PRIVATE;
109			if (vm_flags & VM_MAP_FIXED)
110			flags \|= MAP_FIXED;
111			if (vm_flags & VM_MAP_32BIT)
112			flags \|= MAP_32BIT;
113			return flags;
114			}
115			#endif
116
117	gbeauche	1.14	/* Align ADDR and SIZE to 64K boundaries. */
118
119			#ifdef HAVE_WIN32_VM
120			static inline LPVOID align_addr_segment(LPVOID addr)
121			{
122	gbeauche	1.28	return (LPVOID)(((vm_uintptr_t)addr) & -((vm_uintptr_t)65536));
123	gbeauche	1.14	}
124
125			static inline DWORD align_size_segment(LPVOID addr, DWORD size)
126			{
127	gbeauche	1.28	return size + ((vm_uintptr_t)addr - (vm_uintptr_t)align_addr_segment(addr));
128	gbeauche	1.14	}
129			#endif
130
131			/* Translate generic VM prot flags to host values. */
132
133			#ifdef HAVE_WIN32_VM
134			static int translate_prot_flags(int prot_flags)
135			{
136			int prot = PAGE_READWRITE;
137			if (prot_flags == (VM_PAGE_EXECUTE \| VM_PAGE_READ \| VM_PAGE_WRITE))
138			prot = PAGE_EXECUTE_READWRITE;
139			else if (prot_flags == (VM_PAGE_EXECUTE \| VM_PAGE_READ))
140			prot = PAGE_EXECUTE_READ;
141			else if (prot_flags == (VM_PAGE_READ \| VM_PAGE_WRITE))
142			prot = PAGE_READWRITE;
143			else if (prot_flags == VM_PAGE_READ)
144			prot = PAGE_READONLY;
145			else if (prot_flags == 0)
146			prot = PAGE_NOACCESS;
147			return prot;
148			}
149			#endif
150
151	gbeauche	1.1	/* Initialize the VM system. Returns 0 if successful, -1 for errors. */
152
153			int vm_init(void)
154			{
155			#ifdef HAVE_MMAP_VM
156			#ifndef zero_fd
157			zero_fd = open("/dev/zero", O_RDWR);
158			if (zero_fd < 0)
159			return -1;
160			#endif
161			#endif
162			return 0;
163			}
164
165			/* Deallocate all internal data used to wrap virtual memory allocators. */
166
167			void vm_exit(void)
168			{
169			#ifdef HAVE_MMAP_VM
170			#ifndef zero_fd
171	gbeauche	1.19	if (zero_fd != -1) {
172			close(zero_fd);
173			zero_fd = -1;
174			}
175	gbeauche	1.1	#endif
176			#endif
177			}
178
179			/* Allocate zero-filled memory of SIZE bytes. The mapping is private
180			and default protection bits are read / write. The return value
181			is the actual mapping address chosen or VM_MAP_FAILED for errors. */
182
183	gbeauche	1.10	void * vm_acquire(size_t size, int options)
184	gbeauche	1.1	{
185			void * addr;
186	gbeauche	1.10
187			// VM_MAP_FIXED are to be used with vm_acquire_fixed() only
188			if (options & VM_MAP_FIXED)
189			return VM_MAP_FAILED;
190
191	gbeauche	1.1	#ifdef HAVE_MACH_VM
192			// vm_allocate() returns a zero-filled memory region
193			if (vm_allocate(mach_task_self(), (vm_address_t *)&addr, size, TRUE) != KERN_SUCCESS)
194			return VM_MAP_FAILED;
195			#else
196			#ifdef HAVE_MMAP_VM
197	gbeauche	1.13	int fd = zero_fd;
198			int the_map_flags = translate_map_flags(options) \| map_flags;
199
200			if ((addr = mmap((caddr_t)next_address, size, VM_PAGE_DEFAULT, the_map_flags, fd, 0)) == (void *)MAP_FAILED)
201	gbeauche	1.1	return VM_MAP_FAILED;
202
203	gbeauche	1.10	// Sanity checks for 64-bit platforms
204			if (sizeof(void ) == 8 && (options & VM_MAP_32BIT) && !((char )addr <= (char *)0xffffffff))
205			return VM_MAP_FAILED;
206
207	gbeauche	1.3	next_address = (char *)addr + size;
208	gbeauche	1.1	#else
209	gbeauche	1.14	#ifdef HAVE_WIN32_VM
210			if ((addr = VirtualAlloc(NULL, size, MEM_RESERVE \| MEM_COMMIT, PAGE_EXECUTE_READWRITE)) == NULL)
211			return VM_MAP_FAILED;
212			#else
213	gbeauche	1.1	if ((addr = calloc(size, 1)) == 0)
214			return VM_MAP_FAILED;
215
216			// Omit changes for protections because they are not supported in this mode
217			return addr;
218			#endif
219			#endif
220	gbeauche	1.14	#endif
221	cebix	1.2
222	gbeauche	1.1	// Explicitely protect the newly mapped region here because on some systems,
223			// say MacOS X, mmap() doesn't honour the requested protection flags.
224			if (vm_protect(addr, size, VM_PAGE_DEFAULT) != 0)
225			return VM_MAP_FAILED;
226
227			return addr;
228			}
229
230			/* Allocate zero-filled memory at exactly ADDR (which must be page-aligned).
231			Retuns 0 if successful, -1 on errors. */
232
233	gbeauche	1.10	int vm_acquire_fixed(void * addr, size_t size, int options)
234	gbeauche	1.1	{
235	gbeauche	1.10	// Fixed mappings are required to be private
236			if (options & VM_MAP_SHARED)
237			return -1;
238
239	gbeauche	1.1	#ifdef HAVE_MACH_VM
240			// vm_allocate() returns a zero-filled memory region
241			if (vm_allocate(mach_task_self(), (vm_address_t *)&addr, size, 0) != KERN_SUCCESS)
242			return -1;
243			#else
244			#ifdef HAVE_MMAP_VM
245	gbeauche	1.21	int fd = zero_fd;
246			int the_map_flags = translate_map_flags(options) \| map_flags \| MAP_FIXED;
247	gbeauche	1.10
248	gbeauche	1.21	if (mmap((caddr_t)addr, size, VM_PAGE_DEFAULT, the_map_flags, fd, 0) == (void *)MAP_FAILED)
249	gbeauche	1.1	return -1;
250			#else
251	gbeauche	1.14	#ifdef HAVE_WIN32_VM
252			// Windows cannot allocate Low Memory
253			if (addr == NULL)
254			return -1;
255
256			// Allocate a possibly offset region to align on 64K boundaries
257			LPVOID req_addr = align_addr_segment(addr);
258			DWORD req_size = align_size_segment(addr, size);
259			LPVOID ret_addr = VirtualAlloc(req_addr, req_size, MEM_COMMIT \| MEM_RESERVE, PAGE_EXECUTE_READWRITE);
260			if (ret_addr != req_addr)
261			return -1;
262			#else
263	gbeauche	1.1	// Unsupported
264			return -1;
265			#endif
266			#endif
267	gbeauche	1.14	#endif
268	gbeauche	1.1
269			// Explicitely protect the newly mapped region here because on some systems,
270			// say MacOS X, mmap() doesn't honour the requested protection flags.
271	gbeauche	1.6	if (vm_protect(addr, size, VM_PAGE_DEFAULT) != 0)
272	gbeauche	1.1	return -1;
273
274			return 0;
275			}
276
277			/* Deallocate any mapping for the region starting at ADDR and extending
278			LEN bytes. Returns 0 if successful, -1 on errors. */
279
280			int vm_release(void * addr, size_t size)
281			{
282	gbeauche	1.3	// Safety check: don't try to release memory that was not allocated
283			if (addr == VM_MAP_FAILED)
284			return 0;
285
286	gbeauche	1.1	#ifdef HAVE_MACH_VM
287	gbeauche	1.4	if (vm_deallocate(mach_task_self(), (vm_address_t)addr, size) != KERN_SUCCESS)
288			return -1;
289	gbeauche	1.1	#else
290			#ifdef HAVE_MMAP_VM
291	gbeauche	1.7	if (munmap((caddr_t)addr, size) != 0)
292	gbeauche	1.4	return -1;
293	gbeauche	1.1	#else
294	gbeauche	1.14	#ifdef HAVE_WIN32_VM
295			if (VirtualFree(align_addr_segment(addr), 0, MEM_RELEASE) == 0)
296			return -1;
297			#else
298	gbeauche	1.1	free(addr);
299			#endif
300			#endif
301	gbeauche	1.14	#endif
302	gbeauche	1.4
303			return 0;
304	gbeauche	1.1	}
305
306			/* Change the memory protection of the region starting at ADDR and
307			extending LEN bytes to PROT. Returns 0 if successful, -1 for errors. */
308
309			int vm_protect(void * addr, size_t size, int prot)
310			{
311			#ifdef HAVE_MACH_VM
312			int ret_code = vm_protect(mach_task_self(), (vm_address_t)addr, size, 0, prot);
313			return ret_code == KERN_SUCCESS ? 0 : -1;
314			#else
315			#ifdef HAVE_MMAP_VM
316	gbeauche	1.7	int ret_code = mprotect((caddr_t)addr, size, prot);
317	gbeauche	1.1	return ret_code == 0 ? 0 : -1;
318			#else
319	gbeauche	1.14	#ifdef HAVE_WIN32_VM
320			DWORD old_prot;
321			int ret_code = VirtualProtect(addr, size, translate_prot_flags(prot), &old_prot);
322			return ret_code != 0 ? 0 : -1;
323			#else
324	gbeauche	1.1	// Unsupported
325			return -1;
326			#endif
327			#endif
328	gbeauche	1.14	#endif
329	gbeauche	1.1	}
330
331	gbeauche	1.15	/* Returns the size of a page. */
332
333	gbeauche	1.16	int vm_get_page_size(void)
334	gbeauche	1.15	{
335	gbeauche	1.20	#ifdef HAVE_WIN32_VM
336	gbeauche	1.28	static vm_uintptr_t page_size = 0;
337	gbeauche	1.20	if (page_size == 0) {
338			SYSTEM_INFO si;
339			GetSystemInfo(&si);
340			page_size = si.dwAllocationGranularity;
341			}
342			return page_size;
343	gbeauche	1.15	#else
344	gbeauche	1.20	return getpagesize();
345	gbeauche	1.15	#endif
346			}
347
348	gbeauche	1.1	#ifdef CONFIGURE_TEST_VM_MAP
349	gbeauche	1.18	#include <stdlib.h>
350			#include <signal.h>
351
352			static void fault_handler(int sig)
353			{
354			exit(1);
355			}
356
357	gbeauche	1.1	/* Tests covered here:
358			- TEST_VM_PROT_* program slices actually succeeds when a crash occurs
359			- TEST_VM_MAP_ANON* program slices succeeds when it could be compiled
360			*/
361			int main(void)
362			{
363			vm_init();
364	gbeauche	1.18
365			signal(SIGSEGV, fault_handler);
366			#ifdef SIGBUS
367			signal(SIGBUS, fault_handler);
368			#endif
369	gbeauche	1.1
370	gbeauche	1.28	#define page_align(address) ((char *)((vm_uintptr_t)(address) & -page_size))
371			vm_uintptr_t page_size = vm_get_page_size();
372	gbeauche	1.1
373			const int area_size = 6 * page_size;
374			volatile char * area = (volatile char *) vm_acquire(area_size);
375			volatile char * fault_address = area + (page_size * 7) / 2;
376
377			#if defined(TEST_VM_MMAP_ANON) \|\| defined(TEST_VM_MMAP_ANONYMOUS)
378			if (area == VM_MAP_FAILED)
379			return 1;
380
381			if (vm_release((char *)area, area_size) < 0)
382			return 1;
383
384			return 0;
385			#endif
386
387			#if defined(TEST_VM_PROT_NONE_READ) \|\| defined(TEST_VM_PROT_NONE_WRITE)
388			if (area == VM_MAP_FAILED)
389			return 0;
390
391			if (vm_protect(page_align(fault_address), page_size, VM_PAGE_NOACCESS) < 0)
392			return 0;
393			#endif
394
395			#if defined(TEST_VM_PROT_RDWR_WRITE)
396			if (area == VM_MAP_FAILED)
397			return 1;
398
399			if (vm_protect(page_align(fault_address), page_size, VM_PAGE_READ) < 0)
400			return 1;
401
402			if (vm_protect(page_align(fault_address), page_size, VM_PAGE_READ \| VM_PAGE_WRITE) < 0)
403			return 1;
404			#endif
405
406			#if defined(TEST_VM_PROT_READ_WRITE)
407			if (vm_protect(page_align(fault_address), page_size, VM_PAGE_READ) < 0)
408			return 0;
409			#endif
410
411			#if defined(TEST_VM_PROT_NONE_READ)
412			// this should cause a core dump
413			char foo = *fault_address;
414			return 0;
415			#endif
416
417			#if defined(TEST_VM_PROT_NONE_WRITE) \|\| defined(TEST_VM_PROT_READ_WRITE)
418			// this should cause a core dump
419			*fault_address = 'z';
420			return 0;
421			#endif
422
423			#if defined(TEST_VM_PROT_RDWR_WRITE)
424			// this should not cause a core dump
425			*fault_address = 'z';
426			return 0;
427			#endif
428			}
429			#endif