From: Carl Worth <cworth@cworth.org>
Date: Wed, 12 Jun 2013 23:22:06 +0000 (-0700)
Subject: Fix to actually load the real libGL.so when the application asks for it.
X-Git-Url: https://git.cworth.org/git?a=commitdiff_plain;h=ad0f6ba12d81e4704ce2ba59795d9e1dd31098d7;hp=54157251d30d586e8f97fb594f22bf18e9ac4bbe;p=fips

Fix to actually load the real libGL.so when the application asks for it.

Our wrapper library intercepts calls to dlopen "libGL.so" and returns
a handle to itself. That's correct, and as intended.

Before doing this, however, it's essential to actual dlopen "libGL.so"
for real even though we won't be returning a handle to it. This
ensures that any side effects from that dlopen are taken care of.

This fixes a bug where "fips apitrace replay foo.trace" would cause
Mesa to fail to load its driver as follows (with LIBGL_DEBUG=verbose):

libGL: OpenDriver: trying .../lib/dri/i965_dri.so
libGL error: dlopen .../lib/dri/i965_dri.so failed (.../lib/libdricore9.2.0.so.1: undefined symbol: _glapi_tls_Context)
---

diff --git a/dlwrap.c b/dlwrap.c
index 9f623da..69ffbd1 100644
--- a/dlwrap.c
+++ b/dlwrap.c
@@ -41,10 +41,18 @@ void *
 dlopen (const char *filename, int flag)
 {
 	Dl_info info;
+	void *ret;
+
+	/* Before deciding whether to redirect this dlopen to our own
+	 * library, we call the real dlopen. This assures that any
+	 * expected side-effects from loading the intended library are
+	 * resolved. Below, we may still return a handle pointing to
+	 * our own library, and not what is opened here. */
+	ret = dlwrap_real_dlopen (filename, flag);
 
 	/* Not libGL, so just return real dlopen */
 	if (STRNCMP_LITERAL (filename, "libGL.so"))
-		return dlwrap_real_dlopen (filename, flag);
+		return ret;
 
 	/* Otherwise, for all libGL lookups we redirectl dlopens to
 	 * our own library. If we've resolved libfips_handle before,