1 files changed, 185 insertions, 0 deletions

diff --git a/libraries/eina/src/lib/eina_mmap.c b/libraries/eina/src/lib/eina_mmap.c
new file mode 100644
index 0000000..fb27bd7
--- /dev/null
+++ b/libraries/eina/src/lib/eina_mmap.c
@@ -0,0 +1,185 @@
+/* EINA - EFL data type library
+ * Copyright (C) 2011 Carsten Haitzler
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library;
+ * if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#ifdef HAVE_SIGINFO_T
+
+#ifdef STDC_HEADERS
+# include <stdlib.h>
+# include <stddef.h>
+#else
+# ifdef HAVE_STDLIB_H
+#  include <stdlib.h>
+# endif
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <limits.h>
+#include <signal.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#if HAVE_SIGINFO_H
+# include <siginfo.h>
+#endif
+
+#endif
+
+#include "eina_config.h"
+#include "eina_private.h"
+#include "eina_log.h"
+#include "eina_mmap.h"
+
+/*============================================================================*
+ *                                 Local                                      *
+ *============================================================================*/
+
+static Eina_Bool mmap_safe = EINA_FALSE;
+#ifdef HAVE_SIGINFO_T
+
+static int _eina_mmap_log_dom = -1;
+static int _eina_mmap_zero_fd = -1;
+static long _eina_mmap_pagesize = -1;
+
+#ifdef ERR
+#undef ERR
+#endif
+#define ERR(...) EINA_LOG_DOM_ERR(_eina_mmap_log_dom, __VA_ARGS__)
+
+#ifdef DBG
+#undef DBG
+#endif
+#define DBG(...) EINA_LOG_DOM_DBG(_eina_mmap_log_dom, __VA_ARGS__)
+
+static void
+_eina_mmap_safe_sigbus(int sig __UNUSED__,
+                       siginfo_t *siginfo,
+                       void *ptr __UNUSED__)
+{
+   unsigned char *addr = (unsigned char *)(siginfo->si_addr);
+   int perrno;
+
+   /* save previous errno */
+   perrno = errno;
+   /* if problems was an unaligned access - complain accordingly and abort */
+   if (siginfo->si_code == BUS_ADRALN)
+     {
+        ERR("Unaligned memory access. SIGBUS!!!");
+        errno = perrno;
+        abort();
+     }
+   /* send this to stderr - not eina_log. Specifically want this on stderr */
+   fprintf(stderr,
+           "EINA: Data at address 0x%lx is invalid. Replacing with zero page.\n",
+           (unsigned long)addr);
+   /* align address to the lower page boundary */
+   addr = (unsigned char *)((long)addr & (~(_eina_mmap_pagesize - 1)));
+   /* mmap a pzge of zero's from /dev/zero in there */
+   if (mmap(addr, _eina_mmap_pagesize,
+            PROT_READ | PROT_WRITE | PROT_EXEC,
+            MAP_PRIVATE | MAP_FIXED,
+            _eina_mmap_zero_fd, 0) == MAP_FAILED)
+     {
+        /* mmap of /dev/zero failed :( */
+        perror("mmap");
+        ERR("Failed to mmap() /dev/zero in place of page. SIGBUS!!!");
+        errno = perrno;
+        abort();
+     }
+   /* restore previous errno */
+   errno = perrno;
+}
+#endif
+
+/*============================================================================*
+ *                                   API                                      *
+ *============================================================================*/
+
+EAPI Eina_Bool
+eina_mmap_safety_enabled_set(Eina_Bool enabled)
+{
+#ifndef HAVE_SIGINFO_T
+   (void) enabled;
+   return EINA_FALSE;
+#else
+   if (_eina_mmap_log_dom < 0)
+     {
+        _eina_mmap_log_dom = eina_log_domain_register("eina_mmap",
+                                                         EINA_LOG_COLOR_DEFAULT);
+        if (_eina_mmap_log_dom < 0)
+          {
+             EINA_LOG_ERR("Could not register log domain: eina_mmap");
+             return EINA_FALSE;
+          }
+     }
+
+   enabled = !!enabled;
+
+   if (mmap_safe == enabled) return mmap_safe;
+   if (enabled)
+     {
+        struct sigaction  sa;
+
+        /* find out system page size the cleanest way we can */
+#ifdef _SC_PAGESIZE
+        _eina_mmap_pagesize = sysconf(_SC_PAGESIZE);
+        if (_eina_mmap_pagesize <= 0) return EINA_FALSE;
+#else
+        _eina_mmap_pagesize = 4096;
+#endif
+        /* no zero page device - open it */
+        if (_eina_mmap_zero_fd < 0)
+          {
+             _eina_mmap_zero_fd = open("/dev/zero", O_RDWR);
+             /* if we don;'t have one - fail to set up mmap safety */
+             if (_eina_mmap_zero_fd < 0) return EINA_FALSE;
+          }
+        /* set up signal handler for SIGBUS */
+        sa.sa_sigaction = _eina_mmap_safe_sigbus;
+        sa.sa_flags = SA_RESTART | SA_SIGINFO;
+        sigemptyset(&sa.sa_mask);
+        if (sigaction(SIGBUS, &sa, NULL) == 0) return EINA_FALSE;
+        /* setup of SIGBUS handler failed, lets close zero page dev and fail */
+        close(_eina_mmap_zero_fd);
+        _eina_mmap_zero_fd = -1;
+        return EINA_FALSE;
+     }
+   else
+     {
+        /* reset signal handler to default for SIGBUS */
+        signal(SIGBUS, SIG_DFL);
+     }
+   mmap_safe = enabled;
+   return mmap_safe;
+#endif
+}
+
+EAPI Eina_Bool
+eina_mmap_safety_enabled_get(void)
+{
+   return mmap_safe;
+}