forked from enlightenment/efl
243 lines
7.3 KiB
C
243 lines
7.3 KiB
C
/* EINA - EFL data type library
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* Copyright (C) 2011 Carsten Haitzler
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library;
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* if not, see <http://www.gnu.org/licenses/>.
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#ifdef HAVE_SIGINFO_T
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#ifdef STDC_HEADERS
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# include <stdlib.h>
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# include <stddef.h>
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#else
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# ifdef HAVE_STDLIB_H
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# include <stdlib.h>
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# endif
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/mman.h>
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#include <limits.h>
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#include <signal.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <unistd.h>
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#if HAVE_SIGINFO_H
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# include <siginfo.h>
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#endif
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#endif
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#include "eina_config.h"
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#include "eina_private.h"
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#include "eina_log.h"
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#include "eina_mmap.h"
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#include "eina_cpu.h"
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#include "eina_file.h"
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/*============================================================================*
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* Local *
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*============================================================================*/
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static Eina_Bool mmap_safe = EINA_FALSE;
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#ifdef HAVE_SIGINFO_T
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static int _eina_mmap_log_dom = -1;
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static int _eina_mmap_zero_fd = -1;
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static long _eina_mmap_pagesize = -1;
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static struct sigaction _eina_mmap_prev_sigaction;
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#ifdef ERR
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#undef ERR
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#endif
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#define ERR(...) EINA_LOG_DOM_ERR(_eina_mmap_log_dom, __VA_ARGS__)
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#ifdef DBG
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#undef DBG
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#endif
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#define DBG(...) EINA_LOG_DOM_DBG(_eina_mmap_log_dom, __VA_ARGS__)
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static void
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_eina_mmap_safe_sigbus(int sig, siginfo_t *siginfo, void *ptr)
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{
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unsigned char *addr = (unsigned char *)(siginfo->si_addr);
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int perrno;
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/* save previous errno */
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perrno = errno;
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/* if problems was an unaligned access - complain accordingly and abort */
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if (siginfo->si_code != BUS_ADRERR)
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{
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if (siginfo->si_code == BUS_ADRALN)
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ERR("Unaligned memory access - BUS_ADRALN. SIGBUS!!!");
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else if (siginfo->si_code == BUS_OBJERR)
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ERR("Invalid object - BUS_OBJERR. SIGBUS!!!");
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#ifdef BUS_MCEERR_AR
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else if (siginfo->si_code == BUS_MCEERR_AR)
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ERR("Memory Fault - BUS_MCEERR_AR. SIGBUS!!!");
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#endif
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#ifdef BUS_MCEERR_AO
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else if (siginfo->si_code == BUS_MCEERR_AO)
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ERR("Memory Fault - BUS_MCEERR_AO. SIGBUS!!!");
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#endif
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else
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ERR("Memory Fault - Unknown. SIGBUS!!!");
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errno = perrno;
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if (_eina_mmap_prev_sigaction.sa_flags & SA_SIGINFO)
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{
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if (_eina_mmap_prev_sigaction.sa_sigaction)
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{
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_eina_mmap_prev_sigaction.sa_sigaction(sig, siginfo, ptr);
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if (_eina_mmap_prev_sigaction.sa_flags & SA_RESETHAND)
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_eina_mmap_prev_sigaction.sa_sigaction = NULL;
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if (_eina_mmap_prev_sigaction.sa_flags & SA_RESTART)
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return;
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}
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abort();
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}
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else
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{
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if (_eina_mmap_prev_sigaction.sa_handler == SIG_IGN)
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return;
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else if (_eina_mmap_prev_sigaction.sa_handler == SIG_DFL)
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abort();
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else if (_eina_mmap_prev_sigaction.sa_handler)
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{
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_eina_mmap_prev_sigaction.sa_handler(sig);
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abort();
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}
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}
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}
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// Look into mmaped Eina_File if it was one of them, mark it as having
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// I/O errors and then mmap a zero page in place here
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if (eina_file_mmap_faulty(addr, _eina_mmap_pagesize))
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{
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// Send this to stderr not eina_log. Specifically want this on stderr
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fprintf(stderr,
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"EINA: Data at address 0x%lx is invalid. "
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"Replacing with zero page.\n",
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(unsigned long)addr);
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/* align address to the lower page boundary */
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addr = (unsigned char *)((long)addr & (~(_eina_mmap_pagesize - 1)));
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/* mmap a pzge of zero's from /dev/zero in there */
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if (mmap(addr, _eina_mmap_pagesize,
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PROT_READ | PROT_WRITE | PROT_EXEC,
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MAP_PRIVATE | MAP_FIXED,
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_eina_mmap_zero_fd, 0) == MAP_FAILED)
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{
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/* mmap of /dev/zero failed :( */
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perror("mmap");
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ERR("Failed to mmap() /dev/zero in place of page. SIGBUS!!!");
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errno = perrno;
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abort();
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}
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}
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else
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{
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ERR("Regular SIGBUS not in an eina_file mmaped file");
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abort();
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}
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/* restore previous errno */
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errno = perrno;
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}
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#endif
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/*============================================================================*
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* API *
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*============================================================================*/
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EAPI Eina_Bool
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eina_mmap_safety_enabled_set(Eina_Bool enabled)
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{
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#ifndef HAVE_SIGINFO_T
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(void) enabled;
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return EINA_FALSE;
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#else
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if (_eina_mmap_log_dom < 0)
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{
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_eina_mmap_log_dom = eina_log_domain_register("eina_mmap",
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EINA_LOG_COLOR_DEFAULT);
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if (_eina_mmap_log_dom < 0)
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{
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EINA_LOG_ERR("Could not register log domain: eina_mmap");
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return EINA_FALSE;
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}
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}
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enabled = !!enabled;
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if (mmap_safe == enabled) return mmap_safe;
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if (enabled)
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{
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struct sigaction sa;
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/* find out system page size the cleanest way we can */
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_eina_mmap_pagesize = eina_cpu_page_size();
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/* no zero page device - open it */
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if (_eina_mmap_zero_fd < 0)
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{
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#ifdef HAVE_OPEN_CLOEXEC
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_eina_mmap_zero_fd = open("/dev/zero", O_RDWR | O_CLOEXEC);
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/* if we don;'t have one - fail to set up mmap safety */
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if (_eina_mmap_zero_fd < 0) return EINA_FALSE;
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#else
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_eina_mmap_zero_fd = open("/dev/zero", O_RDWR);
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/* if we don;'t have one - fail to set up mmap safety */
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if (_eina_mmap_zero_fd < 0) return EINA_FALSE;
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eina_file_close_on_exec(_eina_mmap_zero_fd, EINA_TRUE);
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#endif
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}
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/* set up signal handler for SIGBUS */
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sa.sa_sigaction = _eina_mmap_safe_sigbus;
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sa.sa_flags = SA_RESTART | SA_SIGINFO;
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sigemptyset(&sa.sa_mask);
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if (sigaction(SIGBUS, &sa, &_eina_mmap_prev_sigaction) == 0) goto done;
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/* setup of SIGBUS handler failed, lets close zero page dev and fail */
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close(_eina_mmap_zero_fd);
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_eina_mmap_zero_fd = -1;
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return EINA_FALSE;
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}
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else
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{
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/* reset signal handler to default for SIGBUS */
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if (_eina_mmap_zero_fd >= 0)
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{
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close(_eina_mmap_zero_fd);
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_eina_mmap_zero_fd = -1;
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}
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signal(SIGBUS, SIG_DFL);
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}
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done:
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mmap_safe = enabled;
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return mmap_safe;
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#endif
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}
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EAPI Eina_Bool
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eina_mmap_safety_enabled_get(void)
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{
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return mmap_safe;
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}
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