| /* posix.c -- POSIX file I/O routines for the backtrace library. |
| Copyright (C) 2012-2020 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/stat.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| |
| #include "backtrace.h" |
| #include "internal.h" |
| |
| #ifndef O_BINARY |
| #define O_BINARY 0 |
| #endif |
| |
| #ifndef O_CLOEXEC |
| #define O_CLOEXEC 0 |
| #endif |
| |
| #ifndef FD_CLOEXEC |
| #define FD_CLOEXEC 1 |
| #endif |
| |
| /* Open a file for reading. */ |
| |
| int |
| backtrace_open (const char *filename, backtrace_error_callback error_callback, |
| void *data, int *does_not_exist) |
| { |
| int descriptor; |
| |
| if (does_not_exist != NULL) |
| *does_not_exist = 0; |
| |
| descriptor = open (filename, (int) (O_RDONLY | O_BINARY | O_CLOEXEC)); |
| if (descriptor < 0) |
| { |
| /* If DOES_NOT_EXIST is not NULL, then don't call ERROR_CALLBACK |
| if the file does not exist. We treat lacking permission to |
| open the file as the file not existing; this case arises when |
| running the libgo syscall package tests as root. */ |
| if (does_not_exist != NULL && (errno == ENOENT || errno == EACCES)) |
| *does_not_exist = 1; |
| else |
| error_callback (data, filename, errno); |
| return -1; |
| } |
| |
| #ifdef HAVE_FCNTL |
| /* Set FD_CLOEXEC just in case the kernel does not support |
| O_CLOEXEC. It doesn't matter if this fails for some reason. |
| FIXME: At some point it should be safe to only do this if |
| O_CLOEXEC == 0. */ |
| fcntl (descriptor, F_SETFD, FD_CLOEXEC); |
| #endif |
| |
| return descriptor; |
| } |
| |
| /* Close DESCRIPTOR. */ |
| |
| int |
| backtrace_close (int descriptor, backtrace_error_callback error_callback, |
| void *data) |
| { |
| if (close (descriptor) < 0) |
| { |
| error_callback (data, "close", errno); |
| return 0; |
| } |
| return 1; |
| } |