if (--shmdesc->refcnt)
return TRUE;
#if SHM_FD_PASSING
- if (shmdesc->is_fd)
+ if (shmdesc->is_fd) {
+ if (shmdesc->busfault)
+ busfault_unregister(shmdesc->busfault);
munmap(shmdesc->addr, shmdesc->size);
- else
+ } else
#endif
shmdt(shmdesc->addr);
for (prev = &Shmsegs; *prev != shmdesc; prev = &(*prev)->next);
}
#ifdef SHM_FD_PASSING
+
+static void
+ShmBusfaultNotify(void *context)
+{
+ ShmDescPtr shmdesc = context;
+
+ ErrorF("shared memory 0x%x truncated by client\n",
+ (unsigned int) shmdesc->resource);
+ busfault_unregister(shmdesc->busfault);
+ shmdesc->busfault = NULL;
+ FreeResource (shmdesc->resource, RT_NONE);
+}
+
static int
ProcShmAttachFd(ClientPtr client)
{
shmdesc->refcnt = 1;
shmdesc->writable = !stuff->readOnly;
shmdesc->size = statb.st_size;
+ shmdesc->resource = stuff->shmseg;
+
+ shmdesc->busfault = busfault_register_mmap(shmdesc->addr, shmdesc->size, ShmBusfaultNotify, shmdesc);
+ if (!shmdesc->busfault) {
+ munmap(shmdesc->addr, shmdesc->size);
+ free(shmdesc);
+ return BadAlloc;
+ }
+
shmdesc->next = Shmsegs;
Shmsegs = shmdesc;
shmdesc->refcnt = 1;
shmdesc->writable = !stuff->readOnly;
shmdesc->size = stuff->size;
+
+ shmdesc->busfault = busfault_register_mmap(shmdesc->addr, shmdesc->size, ShmBusfaultNotify, shmdesc);
+ if (!shmdesc->busfault) {
+ close(fd);
+ munmap(shmdesc->addr, shmdesc->size);
+ free(shmdesc);
+ return BadAlloc;
+ }
+
shmdesc->next = Shmsegs;
Shmsegs = shmdesc;
#define SHM_FD_PASSING 1
#endif
+#ifdef SHM_FD_PASSING
+#include "busfault.h"
+#endif
+
typedef struct _ShmDesc {
struct _ShmDesc *next;
int shmid;
unsigned long size;
#ifdef SHM_FD_PASSING
Bool is_fd;
+ struct busfault *busfault;
XID resource;
#endif
} ShmDescRec, *ShmDescPtr;
;;
esac
+AC_CHECK_FUNCS([sigaction])
+
+BUSFAULT=no
+
+case x"$ac_cv_func_sigaction" in
+ xyes)
+ AC_DEFINE(HAVE_SIGACTION, 1, [Have sigaction function])
+ BUSFAULT=yes
+ ;;
+esac
+
+case x"$BUSFAULT" in
+ xyes)
+ AC_DEFINE(BUSFAULT, 1, [Include busfault OS API])
+ ;;
+esac
+
+AM_CONDITIONAL(BUSFAULT, test x"$BUSFAULT" = xyes)
+
PKG_CHECK_MODULES([XSHMFENCE], $XSHMFENCE,
[HAVE_XSHMFENCE=yes], [HAVE_XSHMFENCE=no])
sdk_HEADERS = \
XIstubs.h \
Xprintf.h \
+ busfault.h \
callback.h \
client.h \
closestr.h \
--- /dev/null
+/*
+ * Copyright © 2013 Keith Packard
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission. The copyright holders make no representations
+ * about the suitability of this software for any purpose. It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#ifndef _BUSFAULT_H_
+#define _BUSFAULT_H_
+
+#include <dix-config.h>
+
+#ifdef BUSFAULT
+
+#include <sys/types.h>
+
+typedef void (*busfault_notify_ptr) (void *context);
+
+struct busfault *
+busfault_register_mmap(void *addr, size_t size, busfault_notify_ptr notify, void *context);
+
+void
+busfault_unregister(struct busfault *busfault);
+
+void
+busfault_check(void);
+
+Bool
+busfault_init(void);
+
+#endif
+
+#endif /* _BUSFAULT_H_ */
/* Use XTrans FD passing support */
#undef XTRANS_SEND_FDS
+/* Wrap SIGBUS to catch MIT-SHM faults */
+#undef BUSFAULT
+
#endif /* _DIX_CONFIG_H_ */
SECURERPC_SRCS = rpcauth.c
XDMCP_SRCS = xdmcp.c
XORG_SRCS = log.c
+BUSFAULT_SRCS = busfault.c
libos_la_SOURCES = \
WaitFor.c \
libos_la_LIBADD += $(LIBUNWIND_LIBS)
endif
+if BUSFAULT
+libos_la_SOURCES += $(BUSFAULT_SRCS)
+endif
+
EXTRA_DIST = $(SECURERPC_SRCS) $(XDMCP_SRCS)
if SPECIAL_DTRACE_OBJECTS
#ifdef DPMSExtension
#include "dpmsproc.h"
#endif
+#include "busfault.h"
#ifdef WIN32
/* Error codes from windows sockets differ from fileio error codes */
SmartScheduleStopTimer();
nready = 0;
+#ifdef BUSFAULT
+ busfault_check();
+#endif
+
/* We need a while loop here to handle
crashed connections and the screen saver timeout */
while (1) {
--- /dev/null
+/*
+ * Copyright © 2013 Keith Packard
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission. The copyright holders make no representations
+ * about the suitability of this software for any purpose. It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#ifdef HAVE_DIX_CONFIG_H
+#include <dix-config.h>
+#endif
+
+#include <X11/Xos.h>
+#include <X11/Xdefs.h>
+#include "misc.h"
+#include <busfault.h>
+#include <list.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <sys/mman.h>
+#include <signal.h>
+
+struct busfault {
+ struct xorg_list list;
+
+ void *addr;
+ size_t size;
+
+ Bool valid;
+
+ busfault_notify_ptr notify;
+ void *context;
+};
+
+static Bool busfaulted;
+static struct xorg_list busfaults;
+
+struct busfault *
+busfault_register_mmap(void *addr, size_t size, busfault_notify_ptr notify, void *context)
+{
+ struct busfault *busfault;
+
+ busfault = calloc(1, sizeof (struct busfault));
+ if (!busfault)
+ return NULL;
+
+ busfault->addr = addr;
+ busfault->size = size;
+ busfault->notify = notify;
+ busfault->context = context;
+ busfault->valid = TRUE;
+
+ xorg_list_add(&busfault->list, &busfaults);
+ return busfault;
+}
+
+void
+busfault_unregister(struct busfault *busfault)
+{
+ xorg_list_del(&busfault->list);
+ free(busfault);
+}
+
+void
+busfault_check(void)
+{
+ struct busfault *busfault, *tmp;
+
+ if (!busfaulted)
+ return;
+
+ busfaulted = FALSE;
+
+ xorg_list_for_each_entry_safe(busfault, tmp, &busfaults, list) {
+ if (!busfault->valid)
+ (*busfault->notify)(busfault->context);
+ }
+}
+
+static void (*previous_busfault_sigaction)(int sig, siginfo_t *info, void *param);
+
+static void
+busfault_sigaction(int sig, siginfo_t *info, void *param)
+{
+ void *fault = info->si_addr;
+ struct busfault *busfault = NULL;
+ void *new_addr;
+
+ /* Locate the faulting address in our list of shared segments
+ */
+ xorg_list_for_each_entry(busfault, &busfaults, list) {
+ if ((char *) busfault->addr <= (char *) fault && (char *) fault < (char *) busfault->addr + busfault->size) {
+ break;
+ }
+ }
+ if (!busfault)
+ goto panic;
+
+ if (!busfault->valid)
+ goto panic;
+
+ busfault->valid = FALSE;
+ busfaulted = TRUE;
+
+ /* The client truncated the file; unmap the shared file, map
+ * /dev/zero over that area and keep going
+ */
+
+ new_addr = mmap(busfault->addr, busfault->size, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE|MAP_FIXED, -1, 0);
+
+ if (new_addr == MAP_FAILED)
+ goto panic;
+
+ return;
+panic:
+ if (previous_busfault_sigaction)
+ (*previous_busfault_sigaction)(sig, info, param);
+ else
+ FatalError("bus error");
+}
+
+Bool
+busfault_init(void)
+{
+ struct sigaction act, old_act;
+
+ act.sa_sigaction = busfault_sigaction;
+ act.sa_flags = SA_SIGINFO;
+ if (sigaction(SIGBUS, &act, &old_act) < 0)
+ return FALSE;
+ previous_busfault_sigaction = old_act.sa_sigaction;
+ xorg_list_init(&busfaults);
+ return TRUE;
+}
}
#endif /* !WIN32 || __CYGWIN__ */
+#include "busfault.h"
+
void
OsInit(void)
{
}
}
#endif /* !WIN32 || __CYGWIN__ */
+#ifdef BUSFAULT
+ busfault_init();
+#endif
#ifdef HAVE_BACKTRACE
/*
projects / platform / upstream / xorg-server.git / commitdiff