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Diffstat (limited to '3rdparty/libbacktrace/mmapio.c')
-rw-r--r-- | 3rdparty/libbacktrace/mmapio.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/3rdparty/libbacktrace/mmapio.c b/3rdparty/libbacktrace/mmapio.c new file mode 100644 index 000000000..1cf4019f6 --- /dev/null +++ b/3rdparty/libbacktrace/mmapio.c @@ -0,0 +1,100 @@ +/* mmapio.c -- File views using mmap. + Copyright (C) 2012-2018 Free Software Foundation, Inc. + Written by Ian Lance Taylor, Google. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + + (1) Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + (2) 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. + + (3) The name of the author may not be used to + endorse or promote products derived from this software without + specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 "config.h" + +#include <errno.h> +#include <sys/types.h> +#include <sys/mman.h> +#include <unistd.h> + +#include "backtrace.h" +#include "internal.h" + +#ifndef MAP_FAILED +#define MAP_FAILED ((void *)-1) +#endif + +/* This file implements file views and memory allocation when mmap is + available. */ + +/* Create a view of SIZE bytes from DESCRIPTOR at OFFSET. */ + +int +backtrace_get_view (struct backtrace_state *state ATTRIBUTE_UNUSED, + int descriptor, off_t offset, size_t size, + backtrace_error_callback error_callback, + void *data, struct backtrace_view *view) +{ + size_t pagesize; + unsigned int inpage; + off_t pageoff; + void *map; + + pagesize = getpagesize (); + inpage = offset % (unsigned int)pagesize; + pageoff = offset - inpage; + + size += inpage; + size = (size + (pagesize - 1)) & ~ (pagesize - 1); + + map = mmap (NULL, size, PROT_READ, MAP_PRIVATE, descriptor, pageoff); + if (map == MAP_FAILED) + { + error_callback (data, "mmap", errno); + return 0; + } + + view->data = (char *) map + inpage; + view->base = map; + view->len = size; + + return 1; +} + +/* Release a view read by backtrace_get_view. */ + +void +backtrace_release_view (struct backtrace_state *state ATTRIBUTE_UNUSED, + struct backtrace_view *view, + backtrace_error_callback error_callback, + void *data) +{ + union { + const void *cv; + void *v; + } const_cast; + + const_cast.cv = view->base; + if (munmap (const_cast.v, view->len) < 0) + error_callback (data, "munmap", errno); +} |