From: Roland McGrath <roland@redhat.com>
Subject: [RHEL5.1 PATCH] x86_64: fix 32-bit ptrace access to debug registers 	(RHBZ#247427)
Date: Thu, 13 Sep 2007 11:46:44 -0700 (PDT)
Bugzilla: 247427
Message-Id: <20070913184644.A4CF24D0424@magilla.localdomain>
Changelog: [x86_64] fix 32-bit ptrace access to debug registers


This one-bit fix corrects the behavior of setting debug registers via
ptrace in 32-bit mode on the x86_64 kernel.  This was a regression
introduced by utrace.  It's long been fixed in Fedora/upstream utrace.


Thanks,
Roland


--- linux-2.6.21.x86_64/arch/x86_64/ia32/ptrace32.c
+++ linux-2.6.21.x86_64/arch/x86_64/ia32/ptrace32.c
@@ -381,7 +381,7 @@ ia32_dbregs_set(struct task_struct *targ
 	/*
 	 * We'll just hijack the native setter to do the real work for us.
 	 */
-	const struct utrace_regset *dbregset = &utrace_x86_64_native.regsets[2];
+	const struct utrace_regset *dbregset = &utrace_x86_64_native.regsets[3];
 	int ret = 0;
 
 	for (pos >>= 2, count >>= 2; count > 0; --count, ++pos) {