41da295eb5
If a client passes a section of memory via file descriptor and then subsequently truncates that file, the underlying pages will be freed and the addresses invalidated. Subsequent accesses to the page will fail with a SIGBUS error. Trap that SIGBUS, figure out which segment was causing the error and then allocate new pages to fill in for that region. Mark the offending shared segment as invalid and free the resource ID so that the client will be able to tell when subsequently attempting to use the segment. Signed-off-by: Keith Packard <keithp@keithp.com> v2: Use MAP_FIXED to simplify the recovery logic (Mark Kettenis) v3: Also catch errors in ShmCreateSegment Conflicts: include/dix-config.h.in include/xorg-config.h.in
100 lines
2.8 KiB
C
100 lines
2.8 KiB
C
/*
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* Copyright © 2003 Keith Packard
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*
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* Permission to use, copy, modify, distribute, and sell this software and its
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* documentation for any purpose is hereby granted without fee, provided that
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* the above copyright notice appear in all copies and that both that
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* copyright notice and this permission notice appear in supporting
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* documentation, and that the name of Keith Packard not be used in
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* advertising or publicity pertaining to distribution of the software without
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* specific, written prior permission. Keith Packard makes no
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* representations about the suitability of this software for any purpose. It
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* is provided "as is" without express or implied warranty.
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*
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* KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
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* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
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* EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
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* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
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* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
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* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
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* PERFORMANCE OF THIS SOFTWARE.
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*/
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#ifndef _SHMINT_H_
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#define _SHMINT_H_
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#include <X11/extensions/shmproto.h>
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#include "screenint.h"
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#include "pixmap.h"
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#include "gc.h"
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#define XSHM_PUT_IMAGE_ARGS \
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DrawablePtr /* dst */, \
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GCPtr /* pGC */, \
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int /* depth */, \
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unsigned int /* format */, \
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int /* w */, \
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int /* h */, \
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int /* sx */, \
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int /* sy */, \
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int /* sw */, \
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int /* sh */, \
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int /* dx */, \
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int /* dy */, \
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char * /* data */
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#define XSHM_CREATE_PIXMAP_ARGS \
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ScreenPtr /* pScreen */, \
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int /* width */, \
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int /* height */, \
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int /* depth */, \
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char * /* addr */
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typedef struct _ShmFuncs {
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PixmapPtr (*CreatePixmap) (XSHM_CREATE_PIXMAP_ARGS);
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void (*PutImage) (XSHM_PUT_IMAGE_ARGS);
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} ShmFuncs, *ShmFuncsPtr;
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#include <protocol-versions.h>
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#if SERVER_SHM_MAJOR_VERSION == 1 && SERVER_SHM_MINOR_VERSION >= 2
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#define SHM_FD_PASSING 1
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#endif
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#ifdef SHM_FD_PASSING
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#include "busfault.h"
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#endif
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typedef struct _ShmDesc {
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struct _ShmDesc *next;
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int shmid;
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int refcnt;
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char *addr;
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Bool writable;
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unsigned long size;
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#ifdef SHM_FD_PASSING
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Bool is_fd;
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struct busfault *busfault;
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XID resource;
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#endif
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} ShmDescRec, *ShmDescPtr;
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#ifdef SHM_FD_PASSING
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#define SHMDESC_IS_FD(shmdesc) ((shmdesc)->is_fd)
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#else
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#define SHMDESC_IS_FD(shmdesc) (0)
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#endif
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extern _X_EXPORT void
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ShmRegisterFuncs(ScreenPtr pScreen, ShmFuncsPtr funcs);
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extern _X_EXPORT void
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ShmRegisterFbFuncs(ScreenPtr pScreen);
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extern _X_EXPORT RESTYPE ShmSegType;
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extern _X_EXPORT int ShmCompletionCode;
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extern _X_EXPORT int BadShmSegCode;
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#endif /* _SHMINT_H_ */
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