Add --enable-asan and --enable-ubsan switches

`configure` now accepts `--enable-asan` and `--enable-ubsan` switches
which results in passing `-fsanitize=address`
and `-fsanitize=undefined`, respectively, to the compiler. Those
flags are enabled in GitHub workflows for ZTS and zloop. Errors
reported by both instrumentations are corrected, except for:

- Memory leak reporting is (temporarily) suppressed. The cost of
  fixing them is relatively high compared to the gains.

- Checksum computing functions in `module/zcommon/zfs_fletcher*`
  have UBSan errors suppressed. It is completely impractical
  to enforce 64-byte payload alignment there due to performance
  impact.

- There's no ASan heap poisoning in `module/zstd/lib/zstd.c`. A custom
  memory allocator is used there rendering that measure
  unfeasible.

- Memory leaks detection has to be suppressed for `cmd/zvol_id`.
  `zvol_id` is run by udev with the help of `ptrace(2)`. Tracing is
  incompatible with memory leaks detection.

Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: szubersk <szuberskidamian@gmail.com>
Closes #12928

cmd/zdb/zdb.c

@@ -8654,7 +8654,7 @@ main(int argc, char **argv)
 			dump_opt[c] += verbose;
 	}
 
-	libspl_assert_ok = (dump_opt['A'] == 1) || (dump_opt['A'] > 2);
+	libspl_set_assert_ok((dump_opt['A'] == 1) || (dump_opt['A'] > 2));
 	zfs_recover = (dump_opt['A'] > 1);
 
 	argc -= optind;

cmd/zfs/zfs_main.c

@@ -575,8 +575,9 @@ usage(boolean_t requested)
 
 		(void) fprintf(fp, gettext("\nSizes are specified in bytes "
 		    "with standard units such as K, M, G, etc.\n"));
-		(void) fprintf(fp, gettext("\nUser-defined properties can "
-		    "be specified by using a name containing a colon (:).\n"));
+		(void) fprintf(fp, "%s", gettext("\nUser-defined properties "
+		    "can be specified by using a name containing a colon "
+		    "(:).\n"));
 		(void) fprintf(fp, gettext("\nThe {user|group|project}"
 		    "[obj]{used|quota}@ properties must be appended with\n"
 		    "a user|group|project specifier of one of these forms:\n"

cmd/zpool/zpool_main.c

@@ -1760,17 +1760,19 @@ zpool_do_create(int argc, char **argv)
 			    "feature@%s", feat->fi_uname);
 
 			if (!nvlist_lookup_string(props, propname, &propval)) {
-				if (strcmp(propval, ZFS_FEATURE_DISABLED) == 0)
+				if (strcmp(propval,
+				    ZFS_FEATURE_DISABLED) == 0) {
 					(void) nvlist_remove_all(props,
 					    propname);
-				if (strcmp(propval,
+				} else if (strcmp(propval,
 				    ZFS_FEATURE_ENABLED) == 0 &&
-				    !requested_features[i])
+				    !requested_features[i]) {
 					(void) fprintf(stderr, gettext(
 					    "Warning: feature \"%s\" enabled "
 					    "but is not in specified "
 					    "'compatibility' feature set.\n"),
 					    feat->fi_uname);
+				}
 			} else if (
 			    enable_pool_features &&
 			    feat->fi_zfs_mod_supported &&
@@ -9210,7 +9212,7 @@ zpool_do_upgrade(int argc, char **argv)
 		}
 	}
 
-	(void) printf(gettext("This system supports ZFS pool feature "
+	(void) printf("%s", gettext("This system supports ZFS pool feature "
 	    "flags.\n\n"));
 	if (showversions) {
 		int i;

cmd/ztest/ztest.c

@@ -631,6 +631,8 @@ fatal(int do_perror, char *message, ...)
 
 	(void) fflush(stdout);
 	buf = umem_alloc(FATAL_MSG_SZ, UMEM_NOFAIL);
+	if (buf == NULL)
+		goto out;
 
 	va_start(args, message);
 	(void) sprintf(buf, "ztest: ");
@@ -644,6 +646,7 @@ fatal(int do_perror, char *message, ...)
 	(void) fprintf(stderr, "%s\n", buf);
 	fatal_msg = buf;			/* to ease debugging */
 
+out:
 	if (ztest_dump_core)
 		abort();
 	else

cmd/zvol_id/zvol_id_main.c

@@ -35,6 +35,21 @@
 #include <sys/zfs_znode.h>
 #include <sys/fs/zfs.h>
 
+#if defined(ZFS_ASAN_ENABLED)
+/*
+ * zvol_id is invoked by udev with the help of ptrace()
+ * making sanitized binary with leak detection croak
+ * because of tracing mechanisms collision
+ */
+extern const char *__asan_default_options(void);
+
+const char *__asan_default_options(void) {
+	return ("abort_on_error=true:halt_on_error=true:"
+		"allocator_may_return_null=true:disable_coredump=false:"
+		"detect_stack_use_after_return=true:detect_leaks=false");
+}
+#endif
+
 static int
 ioctl_get_msg(char *var, int fd)
 {