Add fmemopen_unlocked() and use unlocked ops in fuzzers and some other tests

This might make things marginially faster. I didn't benchmark though.

src/fuzz/fuzz-bus-message.c

@@ -1,13 +1,11 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
 
-#include <errno.h>
-#include <stdio.h>
-
 #include "alloc-util.h"
 #include "bus-dump.h"
 #include "bus-message.h"
 #include "env-util.h"
 #include "fd-util.h"
+#include "fileio.h"
 #include "fuzz.h"
 
 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
@@ -36,7 +34,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
         TAKE_PTR(buffer);
 
         if (getenv_bool("SYSTEMD_FUZZ_OUTPUT") <= 0)
-                assert_se(g = open_memstream(&out, &out_size));
+                assert_se(g = open_memstream_unlocked(&out, &out_size));
 
         bus_message_dump(m, g ?: stdout, BUS_MESSAGE_DUMP_WITH_HEADER);
 

src/fuzz/fuzz-env-file.c

@@ -1,9 +1,10 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
 
-#include <errno.h>
+#include <stdio.h>
 
 #include "alloc-util.h"
 #include "env-file.h"
+#include "fileio.h"
 #include "fd-util.h"
 #include "fuzz.h"
 #include "strv.h"
@@ -15,7 +16,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
         if (size == 0 || size > 65535)
                 return 0;
 
-        f = fmemopen((char*) data, size, "re");
+        f = fmemopen_unlocked((char*) data, size, "re");
         assert_se(f);
 
         /* We don't want to fill the logs with messages about parse errors.

src/fuzz/fuzz-hostname-util.c

@@ -1,9 +1,8 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
 
-#include <errno.h>
-
 #include "alloc-util.h"
 #include "fd-util.h"
+#include "fileio.h"
 #include "fuzz.h"
 #include "hostname-util.h"
 
@@ -14,7 +13,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
         if (size == 0)
                 return 0;
 
-        f = fmemopen((char*) data, size, "re");
+        f = fmemopen_unlocked((char*) data, size, "re");
         assert_se(f);
 
         /* We don't want to fill the logs with messages about parse errors.

src/fuzz/fuzz-json.c

@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
 
 #include "alloc-util.h"
+#include "fileio.h"
 #include "fd-util.h"
 #include "fuzz.h"
 #include "json.h"
@@ -14,13 +15,13 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
         if (size == 0)
                 return 0;
 
-        f = fmemopen((char*) data, size, "re");
+        f = fmemopen_unlocked((char*) data, size, "re");
         assert_se(f);
 
         if (json_parse_file(f, NULL, &v, NULL, NULL) < 0)
                 return 0;
 
-        g = open_memstream(&out, &out_size);
+        g = open_memstream_unlocked(&out, &out_size);
         assert_se(g);
 
         json_variant_dump(v, 0, g, NULL);

src/fuzz/fuzz-nspawn-oci.c

@@ -1,9 +1,8 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
 
-#include <errno.h>
-
 #include "alloc-util.h"
 #include "fd-util.h"
+#include "fileio.h"
 #include "fuzz.h"
 #include "nspawn-oci.h"
 
@@ -14,7 +13,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
         if (size == 0)
                 return 0;
 
-        f = fmemopen((char*) data, size, "re");
+        f = fmemopen_unlocked((char*) data, size, "re");
         assert_se(f);
 
         /* We don't want to fill the logs with messages about parse errors.

src/fuzz/fuzz-nspawn-settings.c

@@ -1,9 +1,8 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
 
-#include <errno.h>
-
 #include "alloc-util.h"
 #include "fd-util.h"
+#include "fileio.h"
 #include "fuzz.h"
 #include "nspawn-settings.h"
 
@@ -14,7 +13,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
         if (size == 0)
                 return 0;
 
-        f = fmemopen((char*) data, size, "re");
+        f = fmemopen_unlocked((char*) data, size, "re");
         assert_se(f);
 
         /* We don't want to fill the logs with messages about parse errors.

src/fuzz/fuzz-unit-file.c

@@ -24,7 +24,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
         if (size == 0)
                 return 0;
 
-        f = fmemopen((char*) data, size, "re");
+        f = fmemopen_unlocked((char*) data, size, "re");
         assert_se(f);
 
         if (read_line(f, LINE_MAX, &p) < 0)
@@ -75,7 +75,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
                             config_item_perf_lookup, load_fragment_gperf_lookup,
                             CONFIG_PARSE_ALLOW_INCLUDE, u);
 
-        g = open_memstream(&out, &out_size);
+        g = open_memstream_unlocked(&out, &out_size);
         assert_se(g);
 
         unit_dump(u, g, "");