glucose and xgl progress
José Fonseca
jrfonseca at tungstengraphics.com
Wed Sep 19 03:20:49 PDT 2007
On Tue, 18 Sep 2007 18:47:09 +0100, José Fonseca wrote:
> At this moment, Xgl in glucose-2 branch runs normal 2D and XVideo apps
> OK. However GLX crashes. The problem seems to be duplicate symbols in
> dynamic shared libraries. Namely, Xgl seems to be picking dynamically
> symbols from glxcmds.c inside my system's /usr/lib/libGL.so (that comes
> from Mesa) and the glxcmds.c that lives in xserver/GL/glx .
>
> I'm not sure if this problem was caused by my changes to get Xgl
> compile, or to recent changes to Mesa/Xorg source. Can anybody provide
> some hints?
I've discovered a bit deeper: one function, __glXFreeContext, exists both in /
usr/lib/libGl.so and /opt/xorg/lib/xorg/modules/xgl/libglxext.so :
$ grep __glXFreeContext /usr/lib/libGL.so
Binary file /usr/lib/libGL.so matches
$ grep __glXFreeContext /opt/xorg/lib/xorg/modules/xgl/libglxext.so
Binary file /opt/xorg/lib/xorg/modules/xgl/libglxext.so matches
It is *not* an undefined symbol in libglxext.so:
$ ldd -r /opt/xorg/lib/xorg/modules/xgl/libglxext.so
undefined symbol: PixmapWidthPaddingInfo (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
linux-gate.so.1 => (0xb7f86000)
libm.so.6 => /lib/i686/cmov/libm.so.6 (0xb7c2d000)
librt.so.1 => /lib/i686/cmov/librt.so.1 (0xb7c24000)
libc.so.6 => /lib/i686/cmov/libc.so.6 (0xb7adb000)
/lib/ld-linux.so.2 (0x80000000)
libpthread.so.0 => /lib/i686/cmov/libpthread.so.0 (0xb7ac4000)
undefined symbol: screenInfo (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: StandardMinorOpcode (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: Xstrdup (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: Xrealloc (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: CreateScratchGC (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: ErrorF (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: Xalloc (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: AttendClient (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: LookupIDByType (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: LogMessage (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: WriteToClient (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: FakeClientID (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: FreeResourceByType (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: DamageDestroy (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: FindWindowWithOptional (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: AllocColor (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: FreeResource (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: Xcalloc (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: Xfree (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: ResetCurrentRequest (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: dixLookupDrawable (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: CreateNewResourceType (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: QueryColors (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: LegalNewID (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: FreeScratchGC (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: IgnoreClient (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: AddExtensionAlias (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: DamageUnregister (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: ValidateGC (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: dixChangeGC (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: AddExtension (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: AddResource (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: FatalError (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
undefined symbol: FreeColors (/opt/xorg/lib/xorg/modules/xgl/libglxext.so)
However, when loaded, references to __glXFreeContext *inside*
libglxgext.so are linked to the external __glXFreeContext in libGL.so:
$ LD_DEBUG=all /opt/xorg/bin/Xgl :1 -ac -accel glx:pbuffer -accel xv:fbo
...
32507: symbol=__glXFreeContext; lookup in file=/opt/xorg/bin/Xgl [0]
32507: symbol=__glXFreeContext; lookup in file=/opt/xorg/lib/libXfont.so.1 [0]
32507: symbol=__glXFreeContext; lookup in file=/opt/xorg/lib/libXau.so.6 [0]
32507: symbol=__glXFreeContext; lookup in file=/opt/xorg/lib/libfontenc.so.1 [0]
32507: symbol=__glXFreeContext; lookup in file=/opt/xorg/lib/libpixman-1.so.0 [0]
32507: symbol=__glXFreeContext; lookup in file=/opt/xorg/lib/libXdmcp.so.6 [0]
32507: symbol=__glXFreeContext; lookup in file=/opt/xorg/lib/libglitz-glx.so.1 [0]
32507: symbol=__glXFreeContext; lookup in file=/opt/xorg/lib/libX11.so.6 [0]
32507: symbol=__glXFreeContext; lookup in file=/lib/i686/cmov/libpthread.so.0 [0]
32507: symbol=__glXFreeContext; lookup in file=/lib/i686/cmov/libdl.so.2 [0]
32507: symbol=__glXFreeContext; lookup in file=/lib/i686/cmov/libm.so.6 [0]
32507: symbol=__glXFreeContext; lookup in file=/lib/i686/cmov/librt.so.1 [0]
32507: symbol=__glXFreeContext; lookup in file=/lib/i686/cmov/libc.so.6 [0]
32507: symbol=__glXFreeContext; lookup in file=/opt/xorg/lib/libglitz.so.1 [0]
32507: symbol=__glXFreeContext; lookup in file=/usr/lib/libfreetype.so.6 [0]
32507: symbol=__glXFreeContext; lookup in file=/usr/lib/libz.so.1 [0]
32507: symbol=__glXFreeContext; lookup in file=/usr/lib/libGL.so.1 [0]
32507: binding file /opt/xorg//lib/xorg/modules/xgl/libglxext.so [0] to /usr/lib/libGL.so.1 [0]: normal symbol `__glXFreeContext'
...
This causes Xgl to crash whenever a GLX client disconnects.
Other symbols are linked OK, but just by chance, e.g.:
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/bin/Xgl [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/lib/libXfont.so.1 [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/lib/libXau.so.6 [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/lib/libfontenc.so.1 [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/lib/libpixman-1.so.0 [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/lib/libXdmcp.so.6 [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/lib/libglitz-glx.so.1 [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/lib/libX11.so.6 [0]
32507: symbol=__glXDrawableInit; lookup in file=/lib/i686/cmov/libpthread.so.0 [0]
32507: symbol=__glXDrawableInit; lookup in file=/lib/i686/cmov/libdl.so.2 [0]
32507: symbol=__glXDrawableInit; lookup in file=/lib/i686/cmov/libm.so.6 [0]
32507: symbol=__glXDrawableInit; lookup in file=/lib/i686/cmov/librt.so.1 [0]
32507: symbol=__glXDrawableInit; lookup in file=/lib/i686/cmov/libc.so.6 [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/lib/libglitz.so.1 [0]
32507: symbol=__glXDrawableInit; lookup in file=/usr/lib/libfreetype.so.6 [0]
32507: symbol=__glXDrawableInit; lookup in file=/usr/lib/libz.so.1 [0]
32507: symbol=__glXDrawableInit; lookup in file=/usr/lib/libGL.so.1 [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/lib/libxcb-xlib.so.0 [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/lib/libxcb.so.1 [0]
32507: symbol=__glXDrawableInit; lookup in file=/lib/ld-linux.so.2 [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/lib/libXext.so.6 [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/lib/libXxf86vm.so.1 [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/lib/libXdamage.so.1 [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/lib/libXfixes.so.3 [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg/lib/libdrm.so.2 [0]
32507: symbol=__glXDrawableInit; lookup in file=/opt/xorg//lib/xorg/modules/xgl/libglxext.so [0]
32507: binding file /opt/xorg//lib/xorg/modules/xgl/libglxext.so [0] to /opt/xorg//lib/xorg/modules/xgl/libglxext.so [0]: normal symbol `__glXDrawableInit'
So the problem is that the dynamic linker is searching libglxext.so
symbols outside libglxext.so first, which is a recipe for disaster.
libtool's -export-dynamic flag is not being used. Using libtool's -module
flag doesn't change anything.
This problem is likely to happen only with DRI's libGL (as closed-source
binary libGL's export different symbols). However DRI drivers were
supported by Xgl in the past, so this problem should have happened before too.
José Fonseca
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