um: link with -lpthread

commit a7df4716d19594b7b3f106f0bc0ca1c548e508e6 upstream.

Similarly to commit fb1770aa78a43530940d0c2dd161e77bc705bdac, with gcc 5
on Ubuntu and CONFIG_STATIC_LINK=y I was seeing these linker errors:

/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/librt.a(timer_create.o): In function `__timer_create_new':
(.text+0xcd): undefined reference to `pthread_once'
/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/librt.a(timer_create.o): In function `__timer_create_new':
(.text+0x126): undefined reference to `pthread_attr_init'
/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/librt.a(timer_create.o): In function `__timer_create_new':
(.text+0x168): undefined reference to `pthread_attr_setdetachstate'
[...]

Obviously we also need -lpthread for librt.a.

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index dacf71a43ad41f678e3a0574c84321bacd0ff30e..ba6c34ea5429535cd303b1aa1d6ebd6ae30dd912 100755 (executable)
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -62,7 +62,7 @@ vmlinux_link()
                        -Wl,--start-group                                    \
                                 ${KBUILD_VMLINUX_MAIN}                      \
                        -Wl,--end-group                                      \
-                       -lutil -lrt ${1}
+                       -lutil -lrt -lpthread ${1}
                rm -f linux
        fi
 }