busybox: do not build SUID binary without an applet

If the merge of all config snippets leads to a SUID binary without any
applets, do not build and install it to reduce the SUID binaries in the
system.

Signed-off-by: Jörg Sommer <joerg.sommer@navimatix.de>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

diff --git a/meta/recipes-core/busybox/busybox.inc b/meta/recipes-core/busybox/busybox.inc
index c7b76a3dd8f2b03f0c93e1c887059e954a15d58c..4ad4cfd763998734c927ffba429eaef5e370701d 100644 (file)
--- a/meta/recipes-core/busybox/busybox.inc
+++ b/meta/recipes-core/busybox/busybox.inc
@@ -172,6 +172,10 @@ do_compile() {
                oe_runmake busybox.cfg.suid
                oe_runmake busybox.cfg.nosuid
 
+               if [ -s busybox.cfg.suid ]; then
+                       with_suid=y
+               fi
+
                # workaround for suid bug 10346
                if ! grep -q "CONFIG_SH_IS_NONE" busybox.cfg.nosuid; then
                        echo "CONFIG_SH_IS_NONE" >> busybox.cfg.suid
@@ -182,7 +186,7 @@ do_compile() {
                done
                merge_config.sh -m .config.orig .config.disable.apps
                cp .config .config.nonapps
-               for s in suid nosuid; do
+               for s in ${with_suid:+suid} nosuid; do
                        cat busybox.cfg.$s | while read item; do
                                grep -w "$item" .config.orig
                        done > .config.app.$s
@@ -206,7 +210,7 @@ do_compile() {
                fi
 
                # cleanup
-               rm .config.app.suid .config.app.nosuid .config.disable.apps .config.nonapps
+               rm ${with_suid:+.config.app.suid} .config.app.nosuid .config.disable.apps .config.nonapps
        else
                oe_runmake busybox_unstripped
                cp busybox_unstripped busybox
@@ -245,9 +249,13 @@ do_install () {
                # can run. Let update-alternatives handle the rest.
                install -d ${D}${base_bindir}
                if [ "${BUSYBOX_SPLIT_SUID}" = "1" ]; then
-                       install -m 4755 ${B}/busybox.suid ${D}${base_bindir}
+                       if [ -e ${B}/busybox.suid ]; then
+                               install -m 4755 ${B}/busybox.suid ${D}${base_bindir}
+                       fi
                        install -m 0755 ${B}/busybox.nosuid ${D}${base_bindir}
-                       install -m 0644 ${S}/busybox.links.suid ${D}${sysconfdir}
+                       if [ -e ${S}/busybox.links.suid ]; then
+                               install -m 0644 ${S}/busybox.links.suid ${D}${sysconfdir}
+                       fi
                        install -m 0644 ${S}/busybox.links.nosuid ${D}${sysconfdir}
                        if grep -q "CONFIG_SH_IS_ASH=y" ${B}/.config; then
                                ln -sf busybox.nosuid ${D}${base_bindir}/sh
@@ -388,10 +396,14 @@ python do_package:prepend () {
 
     dvar = d.getVar('D')
     pn = d.getVar('PN')
-    def set_alternative_vars(links, target):
-        links = d.expand(links)
-        target = d.expand(target)
-        f = open('%s%s' % (dvar, links), 'r')
+    links_prefix = d.expand("${D}${sysconfdir}/busybox.links")
+    target_prefix = d.expand("${base_bindir}/busybox")
+    for suffix in ('', '.suid', '.nosuid'):
+        links = links_prefix + suffix
+        if not os.path.exists(links):
+            continue
+        target = target_prefix + suffix
+        f = open(links, 'r')
         for alt_link_name in f:
             alt_link_name = alt_link_name.strip()
             alt_name = os.path.basename(alt_link_name)
@@ -406,13 +418,6 @@ python do_package:prepend () {
             if os.path.exists('%s%s' % (dvar, target)):
                 d.setVarFlag('ALTERNATIVE_TARGET', alt_name, target)
         f.close()
-        return
-
-    if os.path.exists('%s/etc/busybox.links' % (dvar)):
-        set_alternative_vars("${sysconfdir}/busybox.links", "${base_bindir}/busybox")
-    else:
-        set_alternative_vars("${sysconfdir}/busybox.links.nosuid", "${base_bindir}/busybox.nosuid")
-        set_alternative_vars("${sysconfdir}/busybox.links.suid", "${base_bindir}/busybox.suid")
 }
 
 # This part of code is dedicated to the on target upgrade problem.  It's known