KEYS: Separate the kernel signature checking keyring from module signing

Separate the kernel signature checking keyring from module signing so that it
can be used by code other than the module-signing code.

Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/kernel/Makefile b/kernel/Makefile
index 2c24195..6313698 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -54,8 +54,9 @@
 obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
 obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
 obj-$(CONFIG_UID16) += uid16.o
+obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o
 obj-$(CONFIG_MODULES) += module.o
-obj-$(CONFIG_MODULE_SIG) += module_signing.o modsign_pubkey.o modsign_certificate.o
+obj-$(CONFIG_MODULE_SIG) += module_signing.o
 obj-$(CONFIG_KALLSYMS) += kallsyms.o
 obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
 obj-$(CONFIG_KEXEC) += kexec.o
@@ -141,11 +142,11 @@
 $(obj)/timeconst.h: $(obj)/hz.bc $(src)/timeconst.bc FORCE
 	$(call if_changed,bc)
 
-ifeq ($(CONFIG_MODULE_SIG),y)
 ###############################################################################
 #
 # Roll all the X.509 certificates that we can find together and pull them into
-# the kernel.
+# the kernel so that they get loaded into the system trusted keyring during
+# boot.
 #
 # We look in the source root and the build root for all files whose name ends
 # in ".x509".  Unfortunately, this will generate duplicate filenames, so we
@@ -153,6 +154,7 @@
 # duplicates.
 #
 ###############################################################################
+ifeq ($(CONFIG_SYSTEM_TRUSTED_KEYRING),y)
 X509_CERTIFICATES-y := $(wildcard *.x509) $(wildcard $(srctree)/*.x509)
 X509_CERTIFICATES-$(CONFIG_MODULE_SIG) += signing_key.x509
 X509_CERTIFICATES := $(sort $(foreach CERT,$(X509_CERTIFICATES-y), \
@@ -169,10 +171,11 @@
 endif
 endif
 
-kernel/modsign_certificate.o: $(obj)/x509_certificate_list
+kernel/system_certificates.o: $(obj)/x509_certificate_list
 
 quiet_cmd_x509certs  = CERTS   $@
-      cmd_x509certs  = cat $(X509_CERTIFICATES) /dev/null >$@
+      cmd_x509certs  = cat $(X509_CERTIFICATES) /dev/null >$@ $(foreach X509,$(X509_CERTIFICATES),; echo "  - Including cert $(X509)")
+
 targets += $(obj)/x509_certificate_list
 $(obj)/x509_certificate_list: $(X509_CERTIFICATES) $(obj)/.x509.list
 	$(call if_changed,x509certs)
@@ -182,7 +185,9 @@
 	@echo $(X509_CERTIFICATES) >$@
 
 clean-files := x509_certificate_list .x509.list
+endif
 
+ifeq ($(CONFIG_MODULE_SIG),y)
 ###############################################################################
 #
 # If module signing is requested, say by allyesconfig, but a key has not been