From 49d684369c6682eebca325c55a6c96b7c03f5aeb Mon Sep 17 00:00:00 2001
From: Brooks Davis <brooks@FreeBSD.org>
Date: Wed, 7 Feb 2024 19:38:16 +0000
Subject: [PATCH] libthr: filter rather than link with libsys

The allows gcc + GNU ld to link programs with -m32 -pthread without
erroring out due to _umtx_op_err being undefined (unless -lsys is added
to the link command.

We now always link _umtx_op_err into libthr (not just when it's static)
and filter it with libsys so we call that implementation.  The dynamic
implementations (at least the assembly ones) should likely become stubs
as a further refinement.

Reviewed by:	kib
Differential Revision:	https://reviews.freebsd.org/D43783
---
 lib/libthr/Makefile    | 5 ++---
 lib/libthr/pthread.map | 3 +++
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/libthr/Makefile b/lib/libthr/Makefile
index 1d34f5cb5f0934..932650885deab3 100644
--- a/lib/libthr/Makefile
+++ b/lib/libthr/Makefile
@@ -13,8 +13,6 @@ MK_SSP=	no
 LIB=thr
 SHLIB_MAJOR= 3
 
-LIBADD=	sys
-
 NO_WTHREAD_SAFETY=1
 NO_WCAST_ALIGN.gcc=1    # for gcc 4.2
 CFLAGS+=-DPTHREAD_KERNEL
@@ -47,6 +45,7 @@ CFLAGS+=-D_PTHREAD_FORCED_UNWIND
 .endif
 
 LDFLAGS+=-Wl,-znodelete
+LDFLAGS+=-Wl,--auxiliary,libsys.so.7
 
 VERSION_DEF=${SRCTOP}/lib/libc/Versions.def
 SYMBOL_MAPS=${.CURDIR}/pthread.map
@@ -76,7 +75,7 @@ LIBSYS_SRCTOP=	${.CURDIR:H}/libsys
 .else
 .PATH: ${LIBSYS_SRCTOP}
 .endif
-STATICOBJS+=	_umtx_op_err.o
+OBJS+=	_umtx_op_err.o
 
 .if ${MK_INSTALLLIB} != "no"
 SYMLINKS+=lib${LIB}.a ${LIBDIR}/libpthread.a
diff --git a/lib/libthr/pthread.map b/lib/libthr/pthread.map
index 348fd48df39805..aa9abb7e6114d7 100644
--- a/lib/libthr/pthread.map
+++ b/lib/libthr/pthread.map
@@ -298,6 +298,9 @@ FBSDprivate_1.0 {
 
 	/* ABI bug workaround, indicate that pli->rtli_version is valid */
 	_pli_rtli_version;
+
+	/* Expose stub for libsys filter */
+	_umtx_op_err;
 };
 
 FBSD_1.1 {