paging.h
/*
* DUMA - Red-Zone memory allocator.
* Copyright (C) 2002-2009 Hayati Ayguen <h_ayguen@web.de>, Procitec GmbH
* Copyright (C) 2006 Michael Eddington <meddington@gmail.com>
* Copyright (C) 1987-1999 Bruce Perens <bruce@perens.com>
* License: GNU GPL (GNU General Public License, see COPYING-GPL)
*
* 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
*
*
* FILE CONTENTS:
* internal implementation file
* contains system/platform dependent paging functions
*/
#ifndef DUMA_PAGING_H
#define DUMA_PAGING_H
/*
* Lots of systems are missing the definition of PROT_NONE.
*/
#ifndef PROT_NONE
#define PROT_NONE 0
#endif
/*
* 386 BSD has MAP_ANON instead of MAP_ANONYMOUS.
*/
#if (!defined(MAP_ANONYMOUS) && defined(MAP_ANON))
#define MAP_ANONYMOUS MAP_ANON
#endif
/* declarations */
#include "print.h"
/*
* For some reason, I can't find mprotect() in any of the headers on
* IRIX or SunOS 4.1.2
*/
/* extern C_LINKAGE int mprotect(void * addr, size_t len, int prot); */
#if !defined(WIN32)
static void *startAddr = (void *)0;
#endif
/* Function: stringErrorReport
*
* Get formatted error string and return. For WIN32
* FormatMessage is used, strerror all else.
*/
static const char *stringErrorReport(void) {
#if defined(WIN32)
DWORD LastError;
LPVOID lpMsgBuf;
LastError = GetLastError();
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, LastError,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT) /* Default language */
,
(LPTSTR)&lpMsgBuf, 0, NULL);
return (char *)lpMsgBuf; /* "Unknown error.\n"; */
#else
#ifndef DUMA_NO_STRERROR
static int failing;
if (!failing) {
const char *str;
failing++;
str = strerror(errno);
failing--;
if (str != NULL)
return str;
}
#endif
return DUMA_strerror(errno);
#endif
}
/* Function: mprotectFailed
*
* Report that VirtualProtect or mprotect failed and abort
* program execution.
*/
static void mprotectFailed(void) {
#if defined(WIN32)
DUMA_Abort("VirtualProtect() failed: %s", stringErrorReport());
#else
DUMA_Abort("mprotect() failed: %s.\nCheck README section 'MEMORY USAGE AND "
"EXECUTION SPEED'\n your (Linux) system may limit the number of "
"different page mappings per process",
stringErrorReport());
#endif
}
/* Function: Page_Create
*
* Create memory. Allocates actual memory. Uses
* VirtualAlloc on windows and mmap on unix.
*
* See Also:
* <Page_Delete>
*/
static void *Page_Create(size_t size, int exitonfail, int printerror) {
void *allocation;
#if defined(WIN32)
allocation =
VirtualAlloc(NULL /* address of region to reserve or commit */
,
(DWORD)size /* size of region */
,
(DWORD)MEM_COMMIT /* type of allocation */
,
(DWORD)PAGE_READWRITE /* type of access protection */
);
if ((void *)0 == allocation) {
if (exitonfail)
DUMA_Abort("VirtualAlloc(%d) failed: %s", (DUMA_SIZE)size,
stringErrorReport());
else if (printerror)
DUMA_Print("\nDUMA warning: VirtualAlloc(%d) failed: %s", (DUMA_SIZE)size,
stringErrorReport());
}
#elif defined(MAP_ANONYMOUS)
/*
* In this version, "startAddr" is a _hint_, not a demand.
* When the memory I map here is contiguous with other
* mappings, the allocator can coalesce the memory from two
* or more mappings into one large contiguous chunk, and thus
* might be able to find a fit that would not otherwise have
* been possible. I could _force_ it to be contiguous by using
* the MMAP_FIXED flag, but I don't want to stomp on memory mappings
* generated by other software, etc.
*/
allocation = mmap(startAddr, (int)size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
#ifndef __hpux
/*
* Set the "address hint" for the next mmap() so that it will abut
* the mapping we just created.
*
* HP/UX 9.01 has a kernel bug that makes mmap() fail sometimes
* when given a non-zero address hint, so we'll leave the hint set
* to zero on that system. HP recently told me this is now fixed.
* Someone please tell me when it is probable to assume that most
* of those systems that were running 9.01 have been upgraded.
*/
startAddr = allocation + size;
#endif
if (allocation == (void *)-1) {
allocation = (void *)0;
if (exitonfail)
DUMA_Abort("mmap(%d) failed: %s", (DUMA_SIZE)size, stringErrorReport());
else if (printerror)
DUMA_Print("\nDUMA warning: mmap(%d) failed: %s", (DUMA_SIZE)size,
stringErrorReport());
}
#else
static int devZeroFd = -1;
if (devZeroFd == -1) {
devZeroFd = open("/dev/zero", O_RDWR);
if (devZeroFd < 0)
DUMA_Abort("open() on /dev/zero failed: %s", stringErrorReport());
}
/*
* In this version, "startAddr" is a _hint_, not a demand.
* When the memory I map here is contiguous with other
* mappings, the allocator can coalesce the memory from two
* or more mappings into one large contiguous chunk, and thus
* might be able to find a fit that would not otherwise have
* been possible. I could _force_ it to be contiguous by using
* the MMAP_FIXED flag, but I don't want to stomp on memory mappings
* generated by other software, etc.
*/
allocation = mmap(startAddr, (int)size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
devZeroFd, 0);
startAddr = allocation + size;
if (allocation == (void *)-1) {
allocation = (void *)0;
if (exitonfail)
DUMA_Abort("mmap(%d) failed: %s", (DUMA_SIZE)size, stringErrorReport());
else if (printerror)
DUMA_Print("\nDUMA warning: mmap(%d) failed: %s", (DUMA_SIZE)size,
stringErrorReport());
}
#endif
// TESTING
// memset((void*)allocation, 0, startAddr);
return (void *)allocation;
}
/* Function: Page_AllowAccess
*
* Allow memory access to allocated memory.
*
* See Also:
* <Page_DenyAccess>
*/
void Page_AllowAccess(void *address, size_t size) {
#if defined(WIN32)
SIZE_T OldProtect, retQuery;
MEMORY_BASIC_INFORMATION MemInfo;
size_t tail_size;
BOOL ret;
while (size > 0) {
retQuery = VirtualQuery(address, &MemInfo, sizeof(MemInfo));
if (retQuery < sizeof(MemInfo))
DUMA_Abort("VirtualQuery() failed\n");
tail_size = (size > MemInfo.RegionSize) ? MemInfo.RegionSize : size;
ret = VirtualProtect(
(LPVOID)address /* address of region of committed pages */
,
(DWORD)tail_size /* size of the region */
,
(DWORD)PAGE_READWRITE /* desired access protection */
,
(PDWORD)&OldProtect /* address of variable to get old protection */
);
if (0 == ret)
mprotectFailed();
address = ((char *)address) + tail_size;
size -= tail_size;
}
#else
if (mprotect(address, size, PROT_READ | PROT_WRITE) < 0)
mprotectFailed();
#endif
}
/* Function: Page_DenyAccess
*
* Deny access to allocated memory region.
*
* See Also:
* <Page_AllowAccess>
*/
static void Page_DenyAccess(void *address, size_t size) {
#if defined(WIN32)
SIZE_T OldProtect, retQuery;
MEMORY_BASIC_INFORMATION MemInfo;
size_t tail_size;
BOOL ret;
while (size > 0) {
retQuery = VirtualQuery(address, &MemInfo, sizeof(MemInfo));
if (retQuery < sizeof(MemInfo))
DUMA_Abort("VirtualQuery() failed\n");
tail_size = (size > MemInfo.RegionSize) ? MemInfo.RegionSize : size;
ret = VirtualProtect(
(LPVOID)address /* address of region of committed pages */
,
(DWORD)tail_size /* size of the region */
,
(DWORD)PAGE_NOACCESS /* desired access protection */
,
(PDWORD)&OldProtect /* address of variable to get old protection */
);
if (0 == ret)
mprotectFailed();
address = ((char *)address) + tail_size;
size -= tail_size;
}
#else
if (mprotect(address, size, PROT_NONE) < 0)
mprotectFailed();
#endif
}
/* Function: Page_Delete
*
* Free's DUMA allocated memory. This is the real deal, make sure
* the page is no longer in our slot list first!
*
* See Also:
* <Page_Create>
*/
static void Page_Delete(void *address, size_t size) {
#if defined(WIN32)
void *alloc_address = address;
SIZE_T retQuery;
MEMORY_BASIC_INFORMATION MemInfo;
BOOL ret;
/* release physical memory commited to virtual address space */
while (size > 0) {
retQuery = VirtualQuery(address, &MemInfo, sizeof(MemInfo));
if (retQuery < sizeof(MemInfo))
DUMA_Abort("VirtualQuery() failed\n");
if (MemInfo.State == MEM_COMMIT) {
ret =
VirtualFree((LPVOID)MemInfo.BaseAddress /* base of committed pages */
,
(DWORD)MemInfo.RegionSize /* size of the region */
,
(DWORD)MEM_DECOMMIT /* type of free operation */
);
if (0 == ret)
DUMA_Abort("VirtualFree(,,MEM_DECOMMIT) failed: %s",
stringErrorReport());
}
address = ((char *)address) + MemInfo.RegionSize;
size -= MemInfo.RegionSize;
}
/* release virtual address space */
ret = VirtualFree((LPVOID)alloc_address, (DWORD)0, (DWORD)MEM_RELEASE);
if (0 == ret)
DUMA_Abort("VirtualFree(,,MEM_RELEASE) failed: %s", stringErrorReport());
#else
if (munmap(address, size) < 0)
Page_DenyAccess(address, size);
#endif
}
/* Function: Page_Size
*
* Retrieve page size.
*/
static size_t Page_Size(void) {
#if defined(WIN32)
SYSTEM_INFO SystemInfo;
GetSystemInfo(&SystemInfo);
return (size_t)SystemInfo.dwPageSize;
#elif defined(_SC_PAGESIZE)
return (size_t)sysconf(_SC_PAGESIZE);
#elif defined(_SC_PAGE_SIZE)
return (size_t)sysconf(_SC_PAGE_SIZE);
#else
return getpagesize();
#endif
}
#endif /* DUMA_PAGING_H */