sstate: Fix dir ownership issues in SSTATE_DIR

We currently use mkdir -p to create missing parent directories within SSTATE_DIR.
Reading the man page for mkdir mentions that parent directories are created with
the current umask, *not* the mode passed upon the commandline.

We could fix this by setting and resetting the umask but since we already have
decent python code able to do this, move to using that injecting a python function
into the chain of functions already present.

This should help fix the occasional sstate directory creation with the wrong
permissions.

[YOCTO #14385]

(From OE-Core rev: 90d1e97b7c8bce0fb49714923989c63d243eb2da)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit ae642a4b038c6946e6c8aa9778bf09099d938a31)
Signed-off-by: Steve Sakoman <steve@sakoman.com>

meta/classes-global/sstate.bbclass

@@ -703,7 +703,7 @@ def sstate_package(ss, d):
     if d.getVar('SSTATE_SKIP_CREATION') == '1':
         return
 
-    sstate_create_package = ['sstate_report_unihash', 'sstate_create_package']
+    sstate_create_package = ['sstate_report_unihash', 'sstate_create_pkgdirs', 'sstate_create_package']
     if d.getVar('SSTATE_SIG_KEY'):
         sstate_create_package.append('sstate_sign_package')
 
@@ -810,6 +810,12 @@ python sstate_task_postfunc () {
 }
 sstate_task_postfunc[dirs] = "${WORKDIR}"
 
+python sstate_create_pkgdirs () {
+    # report_unihash can change SSTATE_PKG and mkdir -p in shell doesn't own intermediate directories
+    # correctly so do this in an intermediate python task
+    with bb.utils.umask(0o002):
+        bb.utils.mkdirhier(os.path.dirname(d.getVar('SSTATE_PKG')))
+}
 
 #
 # Shell function to generate a sstate package from a directory
@@ -822,7 +828,6 @@ sstate_create_package () {
 		return
 	fi
 
-	mkdir --mode=0775 -p `dirname ${SSTATE_PKG}`
 	TFILE=`mktemp ${SSTATE_PKG}.XXXXXXXX`
 
 	OPT="-cS"