commit d8026c50d32aef1b346ee75be0e65e7b82f3aa85
Author: Ryota Ozaki <ozaki-r@iij.ad.jp>
Date:   Tue Apr 4 17:23:07 2017 +0900

    Don't strip symbols of rump libraries

diff --git a/share/mk/bsd.lib.mk b/share/mk/bsd.lib.mk
index b657c7b9eea..fcf26784f64 100644
--- a/share/mk/bsd.lib.mk
+++ b/share/mk/bsd.lib.mk
@@ -577,6 +577,9 @@ _LIBLDOPTS+=	-Wl,-rpath,${SHLIBDIR} \
 _LIBLDOPTS+=	-Wl,-rpath-link,${DESTDIR}${SHLIBINSTALLDIR} \
 		-L=${SHLIBINSTALLDIR}
 .endif
+.if ${LIBSYMSTRIP:Uyes} == yes
+_LIBLDOPTS+=	-Wl,-x
+.endif
 
 # gcc -shared now adds -lc automatically. For libraries other than libc and
 # libgcc* we add as a dependency the installed shared libc. For libc and
@@ -635,7 +638,7 @@ ${_LIB.so.full}: ${_MAINLIBDEPS}
 .endif
 	${_MKTARGET_BUILD}
 	rm -f ${.TARGET}
-	${LIBCC} ${LDLIBC} -Wl,-x -shared ${SHLIB_SHFLAGS} \
+	${LIBCC} ${LDLIBC} -shared ${SHLIB_SHFLAGS} \
 	    ${_LDFLAGS.${_LIB}} -o ${.TARGET} ${_LIBLDOPTS} \
 	    -Wl,--whole-archive ${SOLIB} \
 	    -Wl,--no-whole-archive ${_LDADD.${_LIB}}
diff --git a/share/mk/bsd.sys.mk b/share/mk/bsd.sys.mk
index 35c11f569ca..45f42aad561 100644
--- a/share/mk/bsd.sys.mk
+++ b/share/mk/bsd.sys.mk
@@ -308,6 +308,11 @@ OBJCOPYLIBFLAGS_EXTRA=-w -K '[$$][dx]' -K '[$$][dx]\.*'
 # ARM big endian needs to preserve $a/$d/$t symbols for the linker.
 OBJCOPYLIBFLAGS_EXTRA=-w -K '[$$][adt]' -K '[$$][adt]\.*'
 .endif
+
+.if ${LIBSYMSTRIP:Uyes} == yes
 OBJCOPYLIBFLAGS?=${"${.TARGET:M*.po}" != "":?-X:-x} ${OBJCOPYLIBFLAGS_EXTRA}
+.else
+OBJCOPYLIBFLAGS?=${OBJCOPYLIBFLAGS_EXTRA}
+.endif
 
 .endif	# !defined(_BSD_SYS_MK_)
diff --git a/sys/rump/Makefile.rump b/sys/rump/Makefile.rump
index e65cfee1d1b..f2c9a101c3e 100644
--- a/sys/rump/Makefile.rump
+++ b/sys/rump/Makefile.rump
@@ -112,6 +112,11 @@ RUMP_KTRACE?=yes
 CPPFLAGS+=	-DKTRACE
 .endif
 
+RUMP_KEEPSYMBOLS?=no
+.if ${RUMP_KEEPSYMBOLS} == "yes"
+LIBSYMSTRIP=	no
+.endif
+
 # kernel libs should not get linked against libc
 # XXX: actually, we would like to enable this but cannot, since it
 # also leaves out libgcc, it causes problems on some platforms.
diff --git a/sys/rump/README.compileopts b/sys/rump/README.compileopts
index 26a356ef8a6..da2d3529bb6 100644
--- a/sys/rump/README.compileopts
+++ b/sys/rump/README.compileopts
@@ -80,6 +80,16 @@ effect:	Builds NetBSD COMPAT_nn code for each of the elements in the list.
 	NetBSD userspace, and an empty value may be supplied elsewhere.
 
 
+    RUMP_KEEPSYMBOLS
+
+values:	yes|no
+defval:	no
+effect:	Iff "yes", build shared libraries without stripping local symbols,
+	which is equivalent to not passing -x option to the linker.  Keeping
+	local symbols is useful on debugging, for example, symbols of static
+	functions in a backtrace can be seen as well as public functions.
+
+
 ================================================================================
 
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