apparmor: Fix undefined references to zstd_ symbols

Unfortunately the switch to using zstd compression did not properly
ifdef all the code that uses zstd_ symbols. So that if exporting of
binary policy is disabled in the config the compile will fail with the
following errors

security/apparmor/lsm.c:1545: undefined reference to `zstd_min_clevel'
aarch64-linux-ld: security/apparmor/lsm.c:1545: undefined reference to `zstd_max_clevel'

Reported-by: kernel test robot <[e-mail]>
Fixes: 52ccc20c652b ("apparmor: use zstd compression for profile data")
Signed-off-by: John Johansen <[e-mail]>
Acked-by: Jon Tourville <[e-mail]>

security/apparmor/apparmorfs.c

···
 
 static int seq_ns_compress_min_show(struct seq_file *seq, void *v)
 {
-	seq_printf(seq, "%d\n", zstd_min_clevel());
+	seq_printf(seq, "%d\n", AA_MIN_CLEVEL);
 	return 0;
 }
 
 static int seq_ns_compress_max_show(struct seq_file *seq, void *v)
 {
-	seq_printf(seq, "%d\n", zstd_max_clevel());
+	seq_printf(seq, "%d\n", AA_MAX_CLEVEL);
 	return 0;
 }
 

security/apparmor/include/apparmor.h

···
 extern bool aa_g_paranoid_load;
 extern unsigned int aa_g_path_max;
 
+#ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY
+#define AA_MIN_CLEVEL zstd_min_clevel()
+#define AA_MAX_CLEVEL zstd_max_clevel()
+#define AA_DEFAULT_CLEVEL ZSTD_CLEVEL_DEFAULT
+#else
+#define AA_MIN_CLEVEL 0
+#define AA_MAX_CLEVEL 0
+#define AA_DEFAULT_CLEVEL 0
+#endif /* CONFIG_SECURITY_APPARMOR_EXPORT_BINARY */
+
+
 #endif /* __APPARMOR_H */

security/apparmor/lsm.c

···
 #endif
 
 /* policy loaddata compression level */
-int aa_g_rawdata_compression_level = ZSTD_CLEVEL_DEFAULT;
+int aa_g_rawdata_compression_level = AA_DEFAULT_CLEVEL;
 module_param_named(rawdata_compression_level, aa_g_rawdata_compression_level,
 		   aacompressionlevel, 0400);
 
···
 	error = param_set_int(val, kp);
 
 	aa_g_rawdata_compression_level = clamp(aa_g_rawdata_compression_level,
-					       zstd_min_clevel(),
-					       zstd_max_clevel());
+					       AA_MIN_CLEVEL, AA_MAX_CLEVEL);
 	pr_info("AppArmor: policy rawdata compression level set to %d\n",
 		aa_g_rawdata_compression_level);