From 22c68226777b558c3cfb35a47bc2fd4675ccd65a Mon Sep 17 00:00:00 2001
From: Juli Mallett <jmallett@FreeBSD.org>
Date: Tue, 6 Mar 2012 07:47:28 +0000
Subject: [PATCH] When emulating rdhwr for TLS, use the 32-bit offset under
 COMPAT_FREEBSD32.

---
 sys/mips/include/tls.h | 7 +++++++
 sys/mips/mips/trap.c   | 5 +++++
 2 files changed, 12 insertions(+)

diff --git a/sys/mips/include/tls.h b/sys/mips/include/tls.h
index 514a8aceabf1..97e090344dfd 100644
--- a/sys/mips/include/tls.h
+++ b/sys/mips/include/tls.h
@@ -32,6 +32,10 @@
 #ifndef	__MIPS_TLS_H__
 #define	__MIPS_TLS_H__
 
+#if defined(_KERNEL) && !defined(KLD_MODULE) && !defined(_STANDALONE)
+#include "opt_compat.h"
+#endif
+
 /*
  * TLS parameters
  */
@@ -41,6 +45,9 @@
 
 #ifdef __mips_n64
 #define TLS_TCB_SIZE	16
+#ifdef COMPAT_FREEBSD32
+#define TLS_TCB_SIZE32	8
+#endif
 #else
 #define TLS_TCB_SIZE	8
 #endif
diff --git a/sys/mips/mips/trap.c b/sys/mips/mips/trap.c
index 4e365a3325f3..a2cb1d4c9496 100644
--- a/sys/mips/mips/trap.c
+++ b/sys/mips/mips/trap.c
@@ -814,6 +814,11 @@ dofault:
 					if (inst.RType.rd == 29) {
 						frame_regs = &(trapframe->zero);
 						frame_regs[inst.RType.rt] = (register_t)(intptr_t)td->td_md.md_tls;
+#if defined(__mips_n64) && defined(COMPAT_FREEBSD32)
+						if (SV_PROC_FLAG(td->td_proc, SV_ILP32))
+							frame_regs[inst.RType.rt] += TLS_TP_OFFSET + TLS_TCB_SIZE32;
+						else
+#endif
 						frame_regs[inst.RType.rt] += TLS_TP_OFFSET + TLS_TCB_SIZE;
 						trapframe->pc += sizeof(int);
 						goto out;