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Diffstat (limited to 'src/common/ef/page.cpp')
| -rw-r--r-- | src/common/ef/page.cpp | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/src/common/ef/page.cpp b/src/common/ef/page.cpp new file mode 100644 index 00000000..8a5a8f1c --- /dev/null +++ b/src/common/ef/page.cpp @@ -0,0 +1,193 @@ +#include "efence.h" +#include <stdlib.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/mman.h> +#include <stdio.h> +#include <errno.h> +#include <string.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 + +/* + * 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); */ + + + +//#ifdef _64BIT_PLATFORM + static caddr_t startAddr = (caddr_t) 0xc00000000000; +//#else + //static caddr_t startAddr = (caddr_t) 0; +//#endif + + +#if ( !defined(sgi) && !defined(_AIX) ) +extern int sys_nerr; +/*extern char * sys_errlist[];*/ +#endif + +static const char * +stringErrorReport(void) +{ +#if ( defined(sgi) ) + return strerror(oserror()); +#elif ( defined(_AIX) ) + return strerror(errno); +#else + //if ( errno > 0 && errno < sys_nerr ) + return "Unknown error.\n"; + //return sys_errlist[errno]; + //else + //return "Unknown error.\n"; +#endif +} + +/* + * Create memory. + */ +#if defined(MAP_ANONYMOUS) +void * +Page_Create(size_t size) +{ + caddr_t allocation; + + /* + * 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 = (caddr_t) mmap( + startAddr + ,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 == (caddr_t)-1 ) + EF_Exit("mmap() failed: %s", stringErrorReport()); + + return (void *)allocation; +} +#else +void * +Page_Create(size_t size) +{ + static int devZeroFd = -1; + caddr_t allocation; + + if ( devZeroFd == -1 ) { + devZeroFd = open("/dev/zero", O_RDWR); + if ( devZeroFd < 0 ) + EF_Exit( + "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 = (caddr_t) mmap( + startAddr + ,size + ,PROT_READ|PROT_WRITE + ,MAP_PRIVATE + ,devZeroFd + ,0); + + startAddr = allocation + size; + + if ( allocation == (caddr_t)-1 ) + EF_Exit("mmap() failed: %s", stringErrorReport()); + + return (void *)allocation; +} +#endif + +static void +mprotectFailed(void) +{ + EF_Exit("mprotect() failed: %s", stringErrorReport()); +} + +void +Page_AllowAccess(void * address, size_t size) +{ + if ( mprotect((caddr_t)address, size, PROT_READ|PROT_WRITE) < 0 ) + mprotectFailed(); +} + +void +Page_DenyAccess(void * address, size_t size) +{ + if ( mprotect((caddr_t)address, size, PROT_NONE) < 0 ) + mprotectFailed(); +} + +void +Page_Delete(void * address, size_t size) +{ + Page_DenyAccess(address, size); +} + +#if defined(_SC_PAGESIZE) +size_t +Page_Size(void) +{ + return (size_t)sysconf(_SC_PAGESIZE); +} +#elif defined(_SC_PAGE_SIZE) +size_t +Page_Size(void) +{ + return (size_t)sysconf(_SC_PAGE_SIZE); +} +#else +/* extern int getpagesize(); */ +size_t +Page_Size(void) +{ + return getpagesize(); +} +#endif |