NVidia driver (all vers), glxgears works as root, segmentation fault as user

doc.nice · 10-03-2007, 11:32 AM

Hi All,

I recently had big trouble after updating my xorg. All fonts were "invisible". I found out that this is a known problem with old nvidia drivers, so I updated to current ones. (trying everything between 8776 and 100.14.19, the most recent by today)

After the update, the fonts were ok, but when I tried to start any GLX app like a GL screensaver or glxgears, a segmentation fault (segfault, Speicherzugriffsverletzung, memory allocation failure) occured.
BUT, when running glxgears as root, it runs without any trouble.

A search found tons of reports, but no general solution.

Here it is!

run ldd `which glxgears`
to list all used libraries for glxgears.
Then open a root console and check all the listed paths of the ldd output if any user has read access to the libaries. If not, set them.
(for directories: chmod a+rx <dir>, for files: chmod a+r <file>)

Now try running glxgears as ordinary user and be happy...

hope to help you, now going back to staring at rotation gears...
Florian

joselotl · 10-23-2007, 08:16 PM

Hi

I had the same problem and this solution worked for me

Just one thing. In order to find the library which was causing the problems I had to run the ldd `which glxgears` command as root. Running it as a normal user took me to libraries with the correct read permissions.

doc.nice · 10-24-2007, 01:34 AM

nice to hear my work could help someone else.
my ldd output was the same for root and a normal user, so I didn't mind.

thanks for the feedback, others may have the same problems and will be glad of your hint!

Sigg3.net · 03-07-2008, 03:06 PM

I'm quite the noob here, so I just wanted to ask:
1) Does the "=>" markup indicate a symbolic or dynamic link? If so, where's the file at?
2) Are the numbers in parenteses permissions? E.g. (0xb7f4a000) and (0xb6fb8000).

Just trying to figure out what files' permissions I need to alter. I'm adding this to the Zenwalk WIKI with your permission (with kudos).
Typing all that seemed like a hassle, if I could make a bash script

Here's my output from the ldd command, btw:

Code:

  linux-gate.so.1 =>  (0xb7f4a000)
        libGLU.so.1 => /usr/lib/libGLU.so.1 (0xb7ec0000)
        libGL.so.1 => /usr/lib/libGL.so.1 (0xb7e1c000)
        libm.so.6 => /lib/libm.so.6 (0xb7df5000)
        libc.so.6 => /lib/libc.so.6 (0xb7ca7000)
        libX11.so.6 => /usr/lib/libX11.so.6 (0xb7bbf000)
        libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0xb7adb000)
        libgcc_s.so.1 => /usr/lib/libgcc_s.so.1 (0xb7acf000)
        libGLcore.so.1 => /usr/lib/libGLcore.so.1 (0xb6fba000)
        libnvidia-tls.so.1 => /usr/lib/tls/libnvidia-tls.so.1 (0xb6fb8000)
        libXext.so.6 => /usr/lib/libXext.so.6 (0xb6faa000)
        libdl.so.2 => /lib/libdl.so.2 (0xb6fa6000)
        /lib/ld-linux.so.2 (0xb7f4b000)
        libxcb-xlib.so.0 => /usr/lib/libxcb-xlib.so.0 (0xb6fa3000)
        libxcb.so.1 => /usr/lib/libxcb.so.1 (0xb6f8c000)
        libXau.so.6 => /usr/lib/libXau.so.6 (0xb6f89000)
	libXdmcp.so.6 => /usr/lib/libXdmcp.so.6 (0xb6f84000)

Thanks for all help!

doc.nice · 03-07-2008, 05:28 PM

Of course you may add it to the wiki

The arrow just indicates that the file lefthand is found at the righthand position. The righthand path may be the file itself, but may also be a (chain of) symlinks...

The hex numbers in brackets look like memory addresses to me, but I don't know either.

If you wrote a script, you just had to use all the "path-looking texts":
regexp "/(.+/)*.+\.so.*":

Code:

one /
any number of {at least one characters followed by one /}
at least one character
the string ".so"
any number of characters

this will match /libA.so, /a/path/to/libB.so, /libC.so.1.2.3, /anotherPath/libC.so.1.2.3 etc.

I think you can savely do a chmod a+r on all files, there should not be any harm or security hole when anyone can read shared libs (isn't that the use of shared libs?

)

Maybe you have to write a script that will loop over {"file $fname" to check if it is a symlink and follow it} until you reach the real file...

Sigg3.net · 03-11-2008, 07:22 AM

Thanks for the quick reply!
I'll try it and get back to you..

On another side note, wouldn't changing the permissions of a symlink ultimately change the permissions of the file linked to as well/instead?
(Given, of course, permission to change permissions on the target, that I assume for root.)

doc.nice · 03-11-2008, 07:44 AM

Of course you are right, at least on my linux system. There may be others, where symlinks can have their own permissions, I somewhen heared of that, but infact never have seen it in use...