audit: move the compat_xxx_class[] extern declarations to audit_arch.h

[ Upstream commit 7648995 ]

The comapt_xxx_class symbols aren't declared in anything that
lib/comapt_audit.c is including (arm64 build) which is causing
the following sparse warnings:

lib/compat_audit.c:7:10: warning: symbol 'compat_dir_class'
  was not declared. Should it be static?
lib/compat_audit.c:12:10: warning: symbol 'compat_read_class'
  was not declared. Should it be static?
lib/compat_audit.c:17:10: warning: symbol 'compat_write_class'
  was not declared. Should it be static?
lib/compat_audit.c:22:10: warning: symbol 'compat_chattr_class'
  was not declared. Should it be static?
lib/compat_audit.c:27:10: warning: symbol 'compat_signal_class'
  was not declared. Should it be static?

Trying to fix this by chaning compat_audit.c to inclde <linux/audit.h>
does not work on arm64 due to compile errors with the extra includes
that changing this header makes. The simpler thing would be just to
move the definitons of these symbols out of <linux/audit.h> into
<linux/audit_arch.h> which is included.

Fixes: 4b58841 ("audit: Add generic compat syscall support")
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
[PM: rewrite subject line, fixed line length in description]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: bjdooks-ct

include/linux/audit.h

@@ -122,12 +122,6 @@ enum audit_nfcfgop {
 extern int __init audit_register_class(int class, unsigned *list);
 extern int audit_classify_syscall(int abi, unsigned syscall);
 extern int audit_classify_arch(int arch);
-/* only for compat system calls */
-extern unsigned compat_write_class[];
-extern unsigned compat_read_class[];
-extern unsigned compat_dir_class[];
-extern unsigned compat_chattr_class[];
-extern unsigned compat_signal_class[];
 
 /* audit_names->type values */
 #define	AUDIT_TYPE_UNKNOWN	0	/* we don't know yet */

include/linux/audit_arch.h

@@ -23,4 +23,11 @@ enum auditsc_class_t {
 
 extern int audit_classify_compat_syscall(int abi, unsigned syscall);
 
+/* only for compat system calls */
+extern unsigned compat_write_class[];
+extern unsigned compat_read_class[];
+extern unsigned compat_dir_class[];
+extern unsigned compat_chattr_class[];
+extern unsigned compat_signal_class[];
+
 #endif