From 258abbf823f753757e4dddc13ef495f4024680db Mon Sep 17 00:00:00 2001
From: Michal Srb <msrb@suse.com>
Date: Thu, 28 Jun 2012 17:17:12 +0200
Subject: [PATCH] Look for ModuleData only in appropriate library

LoaderSymbol calls dlsym with RTLD_DEFAULT pseudo handle making it search in
every loaded library. In addition glibc adds NODELETE flag to the library
containing the symbol.

It's used in doLoadModule to locate <modulename>ModuleData symbol, the
module's library gets the flag and is kept in memory even after it is
unloaded.

This patch adds LoaderSymbolFromModule function that looks for symbol only in
library specified by handle. That way the NODELETE flag isn't added.

This glibc behavior doesn't seem to be documented, but even if other
implementations differ, there is no reason to search ModuleData symbol outside
the module's library.

Signed-off-by: Michal Srb <msrb@suse.com>
Reviewed-by: Daniel Stone <daniel@fooishbar.org>

v2: Switch LoaderSymbolFromModule arguments order.
    Correct description.
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
---
 hw/xfree86/loader/loader.c  | 6 ++++++
 hw/xfree86/loader/loader.h  | 1 +
 hw/xfree86/loader/loadmod.c | 2 +-
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/hw/xfree86/loader/loader.c b/hw/xfree86/loader/loader.c
index edaefb8f9..5fbea38f8 100644
--- a/hw/xfree86/loader/loader.c
+++ b/hw/xfree86/loader/loader.c
@@ -160,6 +160,12 @@ LoaderSymbol(const char *name)
     return NULL;
 }
 
+void *
+LoaderSymbolFromModule(void *handle, const char *name)
+{
+    return dlsym(handle, name);
+}
+
 void
 LoaderUnload(const char *name, void *handle)
 {
diff --git a/hw/xfree86/loader/loader.h b/hw/xfree86/loader/loader.h
index 5cadd5ad6..c89c6410a 100644
--- a/hw/xfree86/loader/loader.h
+++ b/hw/xfree86/loader/loader.h
@@ -72,5 +72,6 @@ extern unsigned long LoaderOptions;
 
 /* Internal Functions */
 void *LoaderOpen(const char *, int *, int *);
+void *LoaderSymbolFromModule(void *, const char *);
 
 #endif                          /* _LOADER_H */
diff --git a/hw/xfree86/loader/loadmod.c b/hw/xfree86/loader/loadmod.c
index 72020a58c..dd2057318 100644
--- a/hw/xfree86/loader/loadmod.c
+++ b/hw/xfree86/loader/loadmod.c
@@ -956,7 +956,7 @@ doLoadModule(const char *module, const char *path, const char **subdirlist,
             *errmin = 0;
         goto LoadModule_fail;
     }
-    initdata = LoaderSymbol(p);
+    initdata = LoaderSymbolFromModule(ret->handle, p);
     if (initdata) {
         ModuleSetupProc setup;
         ModuleTearDownProc teardown;