101 lines
2.9 KiB
C
101 lines
2.9 KiB
C
/* mmapio.c -- File views using mmap.
|
|
Copyright (C) 2012-2013 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 % 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);
|
|
}
|