ima: rework CONFIG_IMA dependency block

Changing the direct dependencies of IMA_BLACKLIST_KEYRING and
IMA_LOAD_X509 caused them to no longer depend on IMA, but a
a configuration without IMA results in link failures:

arm-linux-gnueabi-ld: security/integrity/iint.o: in function `integrity_load_keys':
iint.c:(.init.text+0xd8): undefined reference to `ima_load_x509'

aarch64-linux-ld: security/integrity/digsig_asymmetric.o: in function `asymmetric_verify':
digsig_asymmetric.c:(.text+0x104): undefined reference to `ima_blacklist_keyring'

Adding explicit dependencies on IMA would fix this, but a more reliable
way to do this is to enclose the entire Kconfig file in an 'if IMA' block.
This also allows removing the existing direct dependencies.

Fixes: be210c6 ("ima: Finish deprecation of IMA_TRUSTED_KEYRING Kconfig")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

security/integrity/ima/Kconfig

@@ -29,9 +29,11 @@ config IMA
 	  to learn more about IMA.
 	  If unsure, say N.
 
+if IMA
+
 config IMA_KEXEC
 	bool "Enable carrying the IMA measurement list across a soft boot"
-	depends on IMA && TCG_TPM && HAVE_IMA_KEXEC
+	depends on TCG_TPM && HAVE_IMA_KEXEC
 	default n
 	help
 	   TPM PCRs are only reset on a hard reboot.  In order to validate
@@ -43,7 +45,6 @@ config IMA_KEXEC
 
 config IMA_MEASURE_PCR_IDX
 	int
-	depends on IMA
 	range 8 14
 	default 10
 	help
@@ -53,15 +54,14 @@ config IMA_MEASURE_PCR_IDX
 
 config IMA_LSM_RULES
 	bool
-	depends on IMA && AUDIT && (SECURITY_SELINUX || SECURITY_SMACK || SECURITY_APPARMOR)
+	depends on AUDIT && (SECURITY_SELINUX || SECURITY_SMACK || SECURITY_APPARMOR)
 	default y
 	help
 	  Disabling this option will disregard LSM based policy rules.
 
 choice
 	prompt "Default template"
 	default IMA_NG_TEMPLATE
-	depends on IMA
 	help
 	  Select the default IMA measurement template.
 
@@ -80,14 +80,12 @@ endchoice
 
 config IMA_DEFAULT_TEMPLATE
 	string
-	depends on IMA
 	default "ima-ng" if IMA_NG_TEMPLATE
 	default "ima-sig" if IMA_SIG_TEMPLATE
 
 choice
 	prompt "Default integrity hash algorithm"
 	default IMA_DEFAULT_HASH_SHA1
-	depends on IMA
 	help
 	   Select the default hash algorithm used for the measurement
 	   list, integrity appraisal and audit log.  The compiled default
@@ -117,7 +115,6 @@ endchoice
 
 config IMA_DEFAULT_HASH
 	string
-	depends on IMA
 	default "sha1" if IMA_DEFAULT_HASH_SHA1
 	default "sha256" if IMA_DEFAULT_HASH_SHA256
 	default "sha512" if IMA_DEFAULT_HASH_SHA512
@@ -126,7 +123,6 @@ config IMA_DEFAULT_HASH
 
 config IMA_WRITE_POLICY
 	bool "Enable multiple writes to the IMA policy"
-	depends on IMA
 	default n
 	help
 	  IMA policy can now be updated multiple times.  The new rules get
@@ -137,7 +133,6 @@ config IMA_WRITE_POLICY
 
 config IMA_READ_POLICY
 	bool "Enable reading back the current IMA policy"
-	depends on IMA
 	default y if IMA_WRITE_POLICY
 	default n if !IMA_WRITE_POLICY
 	help
@@ -147,7 +142,6 @@ config IMA_READ_POLICY
 
 config IMA_APPRAISE
 	bool "Appraise integrity measurements"
-	depends on IMA
 	default n
 	help
 	  This option enables local measurement integrity appraisal.
@@ -304,7 +298,6 @@ config IMA_APPRAISE_SIGNED_INIT
 
 config IMA_MEASURE_ASYMMETRIC_KEYS
 	bool
-	depends on IMA
 	depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE=y
 	default y
 
@@ -323,7 +316,8 @@ config IMA_SECURE_AND_OR_TRUSTED_BOOT
 
 config IMA_DISABLE_HTABLE
 	bool "Disable htable to allow measurement of duplicate records"
-	depends on IMA
 	default n
 	help
 	   This option disables htable to allow measurement of duplicate records.
+
+endif