KEYS: remove CONFIG_KEYS_COMPAT

KEYS_COMPAT now always takes the value of COMPAT && KEYS.  But the
security/keys/ directory is only compiled if KEYS is enabled, so in
practice KEYS_COMPAT is the same as COMPAT.  Therefore, remove the
unnecessary KEYS_COMPAT and just use COMPAT directly.

(Also remove an outdated comment from compat.c.)
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

security/keys/Kconfig

@@ -21,10 +21,6 @@ config KEYS
 
 	  If you are unsure as to whether this is required, answer N.
 
-config KEYS_COMPAT
-	def_bool y
-	depends on COMPAT && KEYS
-
 config KEYS_REQUEST_CACHE
 	bool "Enable temporary caching of the last request_key() result"
 	depends on KEYS

security/keys/Makefile

@@ -17,7 +17,7 @@ obj-y := \
 	request_key_auth.o \
 	user_defined.o
 compat-obj-$(CONFIG_KEY_DH_OPERATIONS) += compat_dh.o
-obj-$(CONFIG_KEYS_COMPAT) += compat.o $(compat-obj-y)
+obj-$(CONFIG_COMPAT) += compat.o $(compat-obj-y)
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_SYSCTL) += sysctl.o
 obj-$(CONFIG_PERSISTENT_KEYRINGS) += persistent.o

security/keys/compat.c

@@ -46,11 +46,6 @@ static long compat_keyctl_instantiate_key_iov(
 
 /*
  * The key control system call, 32-bit compatibility version for 64-bit archs
- *
- * This should only be called if the 64-bit arch uses weird pointers in 32-bit
- * mode or doesn't guarantee that the top 32-bits of the argument registers on
- * taking a 32-bit syscall are zero.  If you can, you should call sys_keyctl()
- * directly.
  */
 COMPAT_SYSCALL_DEFINE5(keyctl, u32, option,
 		       u32, arg2, u32, arg3, u32, arg4, u32, arg5)

security/keys/internal.h

@@ -264,7 +264,7 @@ extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
 			      size_t, struct keyctl_kdf_params __user *);
 extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
 				size_t, struct keyctl_kdf_params *);
-#ifdef CONFIG_KEYS_COMPAT
+#ifdef CONFIG_COMPAT
 extern long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
 				char __user *buffer, size_t buflen,
 				struct compat_keyctl_kdf_params __user *kdf);
@@ -279,7 +279,7 @@ static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
 	return -EOPNOTSUPP;
 }
 
-#ifdef CONFIG_KEYS_COMPAT
+#ifdef CONFIG_COMPAT
 static inline long compat_keyctl_dh_compute(
 				struct keyctl_dh_params __user *params,
 				char __user *buffer, size_t buflen,