s390: Handle KCOV __init vs inline mismatches

When KCOV is enabled all functions get instrumented, unless
the __no_sanitize_coverage attribute is used. To prepare for
__no_sanitize_coverage being applied to __init functions, we have to
handle differences in how GCC's inline optimizations get resolved. For
s390 this exposed a place where the __init annotation was missing but
ended up being "accidentally correct". Fix this cases and force a couple
functions to be inline with __always_inline.

Acked-by: Heiko Carstens <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>

Author: kees

arch/s390/hypfs/hypfs.h

@@ -48,7 +48,7 @@ void hypfs_sprp_exit(void);
 
 int __hypfs_fs_init(void);
 
-static inline int hypfs_fs_init(void)
+static __always_inline int hypfs_fs_init(void)
 {
 	if (IS_ENABLED(CONFIG_S390_HYPFS_FS))
 		return __hypfs_fs_init();

arch/s390/hypfs/hypfs_diag.h

@@ -19,7 +19,7 @@ int diag204_store(void *buf, int pages);
 int __hypfs_diag_fs_init(void);
 void __hypfs_diag_fs_exit(void);
 
-static inline int hypfs_diag_fs_init(void)
+static __always_inline int hypfs_diag_fs_init(void)
 {
 	if (IS_ENABLED(CONFIG_S390_HYPFS_FS))
 		return __hypfs_diag_fs_init();

arch/s390/mm/init.c

@@ -142,7 +142,7 @@ bool force_dma_unencrypted(struct device *dev)
 }
 
 /* protected virtualization */
-static void pv_init(void)
+static void __init pv_init(void)
 {
 	if (!is_prot_virt_guest())
 		return;