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Date:      Tue, 2 Sep 2003 22:38:36 -0400 (EDT)
From:      Daniel Eischen <eischen@vigrid.com>
To:        ports@freebsd.org
Subject:   ports using i386_set_ldt (was: mplayer won't work with libkse/libthr)
Message-ID:  <Pine.GSO.4.10.10309022234250.25430-100000@pcnet5.pcnet.com>

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FYI, any port that uses ldt's in -current won't work with
our new thread libraries (libkse, libthr) unless they
use auto LDT creation.  Below is a patch to make mplayer
work with libkse.  I assume there will be other ports
that need similar patches.

-- 
Dan Eischen

---------- Forwarded message ----------
Date: Tue, 2 Sep 2003 22:15:55 -0400 (EDT)
From: Daniel Eischen <eischen@vigrid.com>
Reply-To: deischen@freebsd.org
To: kde@freebsd.org
Cc: Andy Fawcett <andy@athame.co.uk>
Subject: Re: mplayer won't work with libkse/libthr (was Re: [kde-freebsd]
    Showing off KDE on TechTV)

On Tue, 2 Sep 2003, Daniel Eischen wrote:

> On Tue, 2 Sep 2003, Daniel Eischen wrote:
> 
> > On Tue, 2 Sep 2003, Andy Fawcett wrote:
> > 
> > > Untested fix (no -current here at the moment)
> > > 
> > > pre-configure:
> > >         ${REINPLACE_CMD} "s,-pedantic ,," ${WRKSRC}/configure
> > 
> > Though there were still a lot of warnings, this got it to
> > build (USE_REINPLACE was already true).  Should this be
> > committed as a fix for 5.x?
> 
> mplayer can't work with libkse or libthr because it uses
> static ldt assigments and it clashes with our threads
> libraries.
> 
> Under -current, applications should use dynamic ldts by
> using LDT_AUTO_ALLOC as the first argument to i386_set_ldt().

Here's a patch that makes it work for me with libkse.
It was a quick and dirty patch, so you guys might want
to do it another way...  Should I send-pr it?

-- 
Dan Eischen

--- loader/ldt_keeper.c.orig	Sun Nov 17 12:41:19 2002
+++ loader/ldt_keeper.c	Tue Sep  2 17:55:21 2003
@@ -88,11 +88,16 @@
 #define       LDT_SEL(idx) ((idx) << 3 | 1 << 2 | 3)
 
 /* i got this value from wine sources, it's the first free LDT entry */
+#if defined(__FreeBSD__) && defined(LDT_AUTO_ALLOC)
+#define       TEB_SEL_IDX     LDT_AUTO_ALLOC
+#endif
+
 #ifndef       TEB_SEL_IDX
 #define       TEB_SEL_IDX     17
 #endif
 
-#define       TEB_SEL LDT_SEL(TEB_SEL_IDX)
+static unsigned int fs_ldt = TEB_SEL_IDX;
+
 
 /**
  * here is a small logical problem with Restore for multithreaded programs -
@@ -104,8 +109,10 @@
 #endif
 void Setup_FS_Segment(void)
 {
+    unsigned int ldt_desc = LDT_SEL(fs_ldt);
+
     __asm__ __volatile__(
-	"movl %0,%%eax; movw %%ax, %%fs" : : "i" (TEB_SEL)
+	"movl %0,%%eax; movw %%ax, %%fs" : : "r" (ldt_desc)
     );
 }
 
@@ -211,7 +218,13 @@
         unsigned long d[2];
 
         LDT_EntryToBytes( d, &array );
+#if defined(__FreeBSD__) && defined(LDT_AUTO_ALLOC)
+        ret = i386_set_ldt(LDT_AUTO_ALLOC, (union descriptor *)d, 1);
+        array.entry_number = ret;
+        fs_ldt = ret;
+#else
         ret = i386_set_ldt(array.entry_number, (union descriptor *)d, 1);
+#endif
         if (ret < 0)
         {
             perror("install_fs");
@@ -224,7 +237,7 @@
 #if defined(__svr4__)
     {
 	struct ssd ssd;
-	ssd.sel = TEB_SEL;
+	ssd.sel = LDT_SEL(TEB_SEL_IDX);
 	ssd.bo = array.base_addr;
 	ssd.ls = array.limit - array.base_addr;
 	ssd.acc1 = ((array.read_exec_only == 0) << 1) |





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