| /* ----------------------------------------------------------------------- * |
| * |
| * Copyright 1996-2017 The NASM Authors - All Rights Reserved |
| * See the file AUTHORS included with the NASM distribution for |
| * the specific copyright holders. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following |
| * conditions are met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials provided |
| * with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND |
| * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, |
| * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, |
| * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| * ----------------------------------------------------------------------- */ |
| |
| #include "file.h" |
| |
| /* ----------------------------------------------------------------------- * |
| * Unix-style memory mapping, using mmap(). |
| * ----------------------------------------------------------------------- */ |
| #if defined(HAVE_FILENO) && defined(HAVE_MMAP) |
| |
| /* |
| * System page size |
| */ |
| |
| /* File scope since not all compilers like static data in inline functions */ |
| static size_t nasm_pagemask; |
| |
| static size_t get_pagemask(void) |
| { |
| size_t ps = 0; |
| |
| # if defined(HAVE_SYSCONF) && defined(_SC_PAGESIZE) |
| ps = sysconf(_SC_PAGESIZE); |
| # elif defined(HAVE_GETPAGESIZE) |
| ps = getpagesize(); |
| # elif defined(PAGE_SIZE) |
| ps = PAGE_SIZE; |
| # endif |
| |
| nasm_pagemask = ps = is_power2(ps) ? (ps - 1) : 0; |
| return ps; |
| } |
| |
| static inline size_t pagemask(void) |
| { |
| size_t pm = nasm_pagemask; |
| |
| if (unlikely(!pm)) |
| return get_pagemask(); |
| |
| return pm; |
| } |
| |
| /* |
| * Try to map an input file into memory |
| */ |
| const void *nasm_map_file(FILE *fp, off_t start, off_t len) |
| { |
| const char *p; |
| off_t astart; /* Aligned start */ |
| size_t salign; /* Amount of start adjustment */ |
| size_t alen; /* Aligned length */ |
| const size_t page_mask = pagemask(); |
| |
| if (unlikely(!page_mask)) |
| return NULL; /* Page size undefined? */ |
| |
| if (unlikely(!len)) |
| return NULL; /* Mapping nothing... */ |
| |
| if (unlikely(len != (off_t)(size_t)len)) |
| return NULL; /* Address space insufficient */ |
| |
| astart = start & ~(off_t)page_mask; |
| salign = start - astart; |
| alen = (len + salign + page_mask) & ~page_mask; |
| |
| p = mmap(NULL, alen, PROT_READ, MAP_SHARED, fileno(fp), astart); |
| return unlikely(p == MAP_FAILED) ? NULL : p + salign; |
| } |
| |
| /* |
| * Unmap an input file |
| */ |
| void nasm_unmap_file(const void *p, size_t len) |
| { |
| const size_t page_mask = pagemask(); |
| uintptr_t astart; |
| size_t salign; |
| size_t alen; |
| |
| if (unlikely(!page_mask)) |
| return; |
| |
| astart = (uintptr_t)p & ~(uintptr_t)page_mask; |
| salign = (uintptr_t)p - astart; |
| alen = (len + salign + page_mask) & ~page_mask; |
| |
| munmap((void *)astart, alen); |
| } |
| |
| /* ----------------------------------------------------------------------- * |
| * No memory map support at all |
| * XXX: Add a section with Windows support |
| * ----------------------------------------------------------------------- */ |
| #else |
| |
| const void *nasm_map_file(FILE *fp, off_t start, off_t len) |
| { |
| (void)fp; (void)start; (void)len; |
| return NULL; |
| } |
| |
| void nasm_unmap_file(const void *p, size_t len) |
| { |
| (void)p; (void)len; |
| } |
| |
| #endif |