[patch] clear direction flag for signal handlers

[Aggelos Economopoulos <aoiko@xxxxxxxxxxxxxx>]

gcc-4.3 assumes the direction flag is clear on function entry as
specified by the i386 abi. Ensure that is the case when running
a signal handler.

Linux-kernel discussion with gcc people starts here:
http://article.gmane.org/gmane.linux.kernel/650279

Index: platform/pc32/i386/machdep.c
===================================================================
retrieving revision 1.129
diff -u -r1.129 machdep.c
--- platform/pc32/i386/machdep.c
+++ platform/pc32/i386/machdep.c
@@ -515,7 +515,13 @@
 
 	regs->tf_esp = (int)sfp;
 	regs->tf_eip = PS_STRINGS - *(p->p_sysent->sv_szsigcode);
-	regs->tf_eflags &= ~PSL_T;
+
+	/*
+	 * i386 abi specifies that the direction flag must be cleared
+	 * on function entry
+	 */
+	regs->tf_eflags &= ~(PSL_T|PSL_D);
+
 	regs->tf_cs = _ucodesel;
 	regs->tf_ds = _udatasel;
 	regs->tf_es = _udatasel;