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/* enable the POSIX prototypes of mmap/munmap on Solaris */ |
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#ifdef __sun |
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# if __STDC_VERSION__ >= 199901L |
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# define _XOPEN_SOURCE 600 |
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# else |
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# define _XOPEN_SOURCE 500 |
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# endif |
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#endif |
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|
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#ifndef _WIN32 |
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#include <unistd.h> |
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#endif |
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|
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#if !defined USE_MMAP \ |
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&& _POSIX_MAPPED_FILES > 0 \ |
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&& (_POSIX_VERSION >= 200809L || _POSIX_MEMORY_PROTECTION > 0) |
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#include <sys/mman.h> |
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#if !defined MAP_ANONYMOUS && defined MAP_ANON |
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#define MAP_ANONYMOUS MAP_ANON |
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#endif |
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#ifdef MAP_ANONYMOUS |
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#include <limits.h> |
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#if PAGESIZE <= 0 |
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static long pagesize; |
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#define PAGESIZE pagesize ? pagesize : (pagesize = sysconf (_SC_PAGESIZE)) |
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#endif |
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#define USE_MMAP 1 |
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#endif |
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#endif |
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|
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/* we assume natural alignment, uulib only uses ints and chars */ |
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#define ALIGN 1 |
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#define GUARDS 4 |
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|
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static void * |
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safe_alloc (size_t size) |
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{ |
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#if USE_MMAP |
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|
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size_t rounded = (size + ALIGN - 1) & ~(ALIGN - 1); |
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size_t page = PAGESIZE; |
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size_t page_rounded = (rounded + page - 1) & ~(page - 1); |
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void *base = mmap (0, page_rounded + page * GUARDS * 2, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); |
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|
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if (base == (void *)-1) |
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return 0; |
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|
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mprotect (base, page * GUARDS, PROT_NONE); /* beginning */ |
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mprotect (page_rounded + page * GUARDS + (char *)base, page * GUARDS, PROT_NONE); /* end */ |
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|
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return page * GUARDS + (page_rounded - rounded) + (char *)base; |
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|
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#else |
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return malloc (size); |
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#endif |
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} |
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|
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static void |
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safe_free (void *mem, size_t size) |
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{ |
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#if USE_MMAP |
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|
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size_t rounded = (size + ALIGN - 1) & ~(ALIGN - 1); |
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size_t page = PAGESIZE; |
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size_t page_rounded = (rounded + page - 1) & ~(page - 1); |
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|
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if (!mem) |
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return; |
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|
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mem = (char *)mem - page * GUARDS - (page_rounded - rounded); |
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|
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munmap (mem, page_rounded + page * GUARDS * 2); |
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|
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#else |
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free (size); |
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#endif |
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} |
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