From: Simon Schubert <corecode@dragonflybsd.org>
Date: Sat, 19 Jan 2008 13:30:51 +0000 (+0000)
Subject: Don't write errno to the GOT, but properly follow the indirection
X-Git-Tag: v2.0.1~1317
X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/d4fca68c8b3aded13954bc509c820f01052faee8

Don't write errno to the GOT, but properly follow the indirection

This only applies to PIC objects without TLS support, i.e. rtld.
This was broken since long but didn't get caught, because rtld is the
only consumer of this configuration and doesn't deal with errno a lot.

Noticed-by:  godlkwrth on IRC while porting WINE
---

diff --git a/lib/libc/i386/sys/cerror.S b/lib/libc/i386/sys/cerror.S
index 97e67207c0..ec892bdf49 100644
--- a/lib/libc/i386/sys/cerror.S
+++ b/lib/libc/i386/sys/cerror.S
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  * $FreeBSD: src/lib/libc/i386/sys/cerror.S,v 1.10 1999/08/27 23:59:38 peter Exp $
- * $DragonFly: src/lib/libc/i386/sys/cerror.S,v 1.5 2005/05/11 19:46:54 dillon Exp $
+ * $DragonFly: src/lib/libc/i386/sys/cerror.S,v 1.6 2008/01/19 13:30:51 corecode Exp $
  */
 
 #include "SYS.h"
@@ -47,11 +47,11 @@ HIDENAME(cerror):
 #ifdef PIC
 	/* The caller must execute the PIC prologue before jumping to cerror. */
 #ifdef __thread
-	movl	%eax, PIC_GOT(CNAME(errno))
+	movl	PIC_GOT(CNAME(errno)),%edx
 #else
 	movl	%gs:12,%edx
-	movl	%eax,(%edx)
 #endif
+	movl	%eax,(%edx)
 	PIC_EPILOGUE
 #else
 
@@ -73,7 +73,8 @@ HIDENAME(cerror):
 #ifdef PIC
 	/* The caller must execute the PIC prologue before jumping to cerror. */
 #ifdef __thread
-	movl    %eax, PIC_GOT(CNAME(errno))
+	movl    PIC_GOT(CNAME(errno)),%ecx
+	movl	%eax,(%ecx)
 #else
 	pushl   %eax
 	leal    errno@TLSGD(,%ebx,1), %eax