kbuild: fix 'make rpm' when CONFIG_LOCALVERSION_AUTO=y and using SCM tree

Running 'make rpm' fails when CONFIG_LOCALVERSION_AUTO=y and using a kernel source
tree under SCM.  This is due to KERNELRELEASE being different when the initial make
is run and when make is run from rpmbuild.

mkspec creates kernel.spec using KERNELRELEASE:

<mkspec>
echo "%files"
echo '%defattr (-, root, root)'
echo "%dir /lib/modules"
echo "/lib/modules/$KERNELRELEASE"
echo "/lib/firmware"
echo "/boot/*"
echo ""
</mkspec>

When CONFIG_LOCALVERSION_AUTO=y scripts/setlocalversion is called and grabs any
additional version info from SCM.  Next, the srctree is tarred up and SCM
information is excluded.

rpmbuild reruns make and in the process generates a new include/config/kernel.release
and thus a new KERNELRELEASE.  However this time the SCM information is gone so
KERNELRELEASE no longer has the additional version information.  When "make modules_install"
runs, it uses the new KERNELRELEASE value to determine where to install the modules.
This conflicts with where the spec file assumes they are going because of the
mis-matching KERNELRELEASE versions.

<snippet>
+ INSTALL_MOD_PATH=/var/tmp/kernel-2.6.29rc4tip01479g5d85422-root
+ make -j16 modules_install
  INSTALL crypto/aead.ko
  INSTALL crypto/cbc.ko
  INSTALL crypto/chainiv.ko
  INSTALL crypto/crc32c.ko
  INSTALL crypto/crypto_algapi.ko
  INSTALL crypto/crypto_blkcipher.ko
  INSTALL crypto/crypto_hash.ko
  INSTALL crypto/cryptomgr.ko
  INSTALL crypto/ecb.ko
  INSTALL crypto/eseqiv.ko
  INSTALL crypto/krng.ko
  INSTALL crypto/md5.ko
  INSTALL crypto/pcbc.ko
  INSTALL crypto/rng.ko
  INSTALL drivers/block/cciss.ko
  INSTALL drivers/hid/hid-dummy.ko
  INSTALL drivers/scsi/iscsi_tcp.ko
  INSTALL drivers/scsi/libiscsi.ko
  INSTALL drivers/scsi/libiscsi_tcp.ko
  INSTALL drivers/scsi/scsi_transport_iscsi.ko
  INSTALL drivers/scsi/scsi_wait_scan.ko
  INSTALL fs/lockd/lockd.ko
  INSTALL fs/nfs/nfs.ko
  INSTALL fs/nfsd/nfsd.ko
  INSTALL lib/libcrc32c.ko
  INSTALL net/sunrpc/sunrpc.ko
  DEPMOD  2.6.29-rc4-tip
+ cp arch/x86/boot/bzImage
/var/tmp/kernel-2.6.29rc4tip01479g5d85422-root/boot/vmlinuz-2.6.29-rc4-tip-01479-g5d85422
+ cp System.map
/var/tmp/kernel-2.6.29rc4tip01479g5d85422-root/boot/System.map-2.6.29-rc4-tip-01479-g5d85422
+ cp .config
/var/tmp/kernel-2.6.29rc4tip01479g5d85422-root/boot/config-2.6.29-rc4-tip-01479-g5d85422
+ cp vmlinux vmlinux.orig
+ bzip2 -9 vmlinux
+ mv vmlinux.bz2
/var/tmp/kernel-2.6.29rc4tip01479g5d85422-root/boot/vmlinux-2.6.29-rc4-tip-01479-g5d85422.bz2
+ mv vmlinux.orig vmlinux
+ /usr/lib/rpm/brp-compress
Processing files: kernel-2.6.29rc4tip01479g5d85422-2
error: File not found:
/var/tmp/kernel-2.6.29rc4tip01479g5d85422-root/lib/modules/2.6.29-rc4-tip-01479-g5d85422

RPM build errors:
    File not found:
/var/tmp/kernel-2.6.29rc4tip01479g5d85422-root/lib/modules/2.6.29-rc4-tip-01479-g5d85422
make[1]: *** [rpm] Error 1
make: *** [rpm] Error 2
</snippet>

I have tested this patch on git -tip, Linus' git tree, and the kernel.org tar files, both
with and without CONFIG_LOCALVERSION_AUTO=y.

Signed-off-by: Josh Hunt <josh@scalex86.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
----

Makefile

@@ -904,12 +904,18 @@ localver = $(subst $(space),, $(string) \
 # and if the SCM is know a tag from the SCM is appended.
 # The appended tag is determined by the SCM used.
 #
-# Currently, only git is supported.
-# Other SCMs can edit scripts/setlocalversion and add the appropriate
-# checks as needed.
+# .scmversion is used when generating rpm packages so we do not loose
+# the version information from the SCM when we do the build of the kernel
+# from the copied source
 ifdef CONFIG_LOCALVERSION_AUTO
-	_localver-auto = $(shell $(CONFIG_SHELL) \
-	                  $(srctree)/scripts/setlocalversion $(srctree))
+
+ifeq ($(wildcard .scmversion),)
+        _localver-auto = $(shell $(CONFIG_SHELL) \
+                         $(srctree)/scripts/setlocalversion $(srctree))
+else
+        _localver-auto = $(shell cat .scmversion 2> /dev/null)
+endif
+
 	localver-auto  = $(LOCALVERSION)$(_localver-auto)
 endif
 

scripts/package/Makefile

@@ -35,9 +35,10 @@ $(objtree)/kernel.spec: $(MKSPEC) $(srctree)/Makefile
 rpm-pkg rpm: $(objtree)/kernel.spec FORCE
 	$(MAKE) clean
 	$(PREV) ln -sf $(srctree) $(KERNELPATH)
+	$(CONFIG_SHELL) $(srctree)/scripts/setlocalversion > $(objtree)/.scmversion
 	$(PREV) tar -cz $(RCS_TAR_IGNORE) -f $(KERNELPATH).tar.gz $(KERNELPATH)/.
 	$(PREV) rm $(KERNELPATH)
-
+	rm -f $(objtree)/.scmversion
 	set -e; \
 	$(CONFIG_SHELL) $(srctree)/scripts/mkversion > $(objtree)/.tmp_version
 	set -e; \