Attachment 128707 Details for Bug 93103 – Test-case for global symbol contamination due to LLVM dependency.

Test-case for global symbol contamination due to LLVM dependency.

llvm-libedit-bug.py (text/plain), 1.88 KB, created by fiach.antaw on 2017-01-02 08:58:01 UTC

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Creator: fiach.antaw

Created: 2017-01-02 08:58:01 UTC

Size: 1.88 KB

patch

obsolete

>#!/usr/bin/env python2
>#
># Test-case for global symbol contamination bug.
>#
># When libGL dlopens the llvmpipe-based swrast driver, it sets RTLD_GLOBAL
># to maintain compatability with third party software (see bug #79469).
># Since LLVM depends on libedit, and swrast depends on LLVM, libedit's symbols
># are loaded as RTLD_GLOBAL.
>#
># Libedit is a BSD-licensed reimplementation of GNU readline containing a
># partial readline compatability layer, and hence shares some symbol names
># with the original readline library. Python's readline module uses symbols
># which are not implemented by libedit, causing some symbols to be resolved to
># libedit and others to be resolved to readline, resulting in program
># misbehaviour (e.g. not cleaning up the terminal correctly after termination)
># and semi-random segfaults. As a specific example, rl_initialize is resolved
># to libedit.so if libgl is loaded and libreadline.so if it is not.
>#
># This is a variant of bug #93103.
># Tested on Debian Sid with mesa commit 62a819184141133478cfdcfa76b62d5bb7e14fd5
>
>import os
>from ctypes import *
>
># Force use of swrast driver
>os.environ['LIBGL_ALWAYS_SOFTWARE'] = "1"
>
># Get an X Display handle to feed libGL
>
>print "Loading libX11"
>libX11 = cdll.LoadLibrary("libX11.so.6")
>libX11.XOpenDisplay.argtypes = [c_char_p]
>libX11.XOpenDisplay.restype = c_void_p
>
>print "Calling XOpenDisplay(None)"
>dpy = libX11.XOpenDisplay(None)
>
># Trigger libGL to dlopen the driver by calling glXQueryVersion
>
>print "Loading libGL"
>libGL = cdll.LoadLibrary("libGL.so.1")
>libGL.glXQueryVersion.argtypes = [c_void_p, POINTER(c_bool), POINTER(c_bool)]
>libGL.glXQueryVersion.restype = c_bool
>print "Calling glXQueryVersion(dpy, None, None)"
>success = libGL.glXQueryVersion(dpy, None, None)
>
># Trigger python to load the readline library
>
>print "Loading readline module"
>import readline
>
># Attempt to use the readline-enhanced raw_input function
>raw_input("Input: ")

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