sd-device: use strjoina() more again in sd_device_new_from_subsystem_sysname()

This reverts a major part of: e17c95af8e450caacde692875b30675cea75211f

Using format strings for concatenating strings is pretty unefficient,
and using PATH_MAX buffers unpretty as well. Let's revert to using
strjoina() as before.

However, to fix the fuzz issue at hand, let's explicitly verify the two
input strings ensuring they are valid path names. This includes a length
check (to 2K each), thus making things prettier, faster and using less
memory again.

src/basic/env-util.c

@@ -572,12 +572,9 @@ char *replace_env_n(const char *format, size_t n, char **env, unsigned flags) {
 
                                 t = strv_env_get_n(env, word+2, e-word-2, flags);
 
-                                k = strjoin(r, t);
-                                if (!k)
+                                if (!strextend(&r, t))
                                         return NULL;
 
-                                free_and_replace(r, k);
-
                                 word = e+1;
                                 state = WORD;
                         } else if (*e == ':') {
@@ -627,12 +624,9 @@ char *replace_env_n(const char *format, size_t n, char **env, unsigned flags) {
                                 else if (!t && state == DEFAULT_VALUE)
                                         t = v = replace_env_n(test_value, e-test_value, env, flags);
 
-                                k = strjoin(r, t);
-                                if (!k)
+                                if (!strextend(&r, t))
                                         return NULL;
 
-                                free_and_replace(r, k);
-
                                 word = e+1;
                                 state = WORD;
                         }
@@ -646,12 +640,9 @@ char *replace_env_n(const char *format, size_t n, char **env, unsigned flags) {
 
                                 t = strv_env_get_n(env, word+1, e-word-1, flags);
 
-                                k = strjoin(r, t);
-                                if (!k)
+                                if (!strextend(&r, t))
                                         return NULL;
 
-                                free_and_replace(r, k);
-
                                 word = e--;
                                 i--;
                                 state = WORD;

src/basic/fileio.c

@@ -371,8 +371,6 @@ int read_virtual_file(const char *filename, size_t max_size, char **ret_contents
         int n_retries;
         bool truncated = false;
 
-        assert(ret_contents);
-
         /* Virtual filesystems such as sysfs or procfs use kernfs, and kernfs can work with two sorts of
          * virtual files. One sort uses "seq_file", and the results of the first read are buffered for the
          * second read. The other sort uses "raw" reads which always go direct to the device. In the latter
@@ -486,7 +484,9 @@ int read_virtual_file(const char *filename, size_t max_size, char **ret_contents
                 return -EBADMSG;
 
         buf[n] = 0;
-        *ret_contents = TAKE_PTR(buf);
+
+        if (ret_contents)
+                *ret_contents = TAKE_PTR(buf);
 
         return !truncated;
 }

src/basic/log.h

@@ -236,6 +236,29 @@ int log_emergency_level(void);
 #define log_error_errno(error, ...)     log_full_errno(LOG_ERR,     error, __VA_ARGS__)
 #define log_emergency_errno(error, ...) log_full_errno(log_emergency_level(), error, __VA_ARGS__)
 
+/* This logs at the specified level the first time it is called, and then
+ * logs at debug. If the specified level is debug, this logs only the first
+ * time it is called. */
+#define log_once(level, ...)                                             \
+        ({                                                               \
+                if (ONCE)                                                \
+                        log_full(level, __VA_ARGS__);                    \
+                else if (LOG_PRI(level) != LOG_DEBUG)                    \
+                        log_debug(__VA_ARGS__);                          \
+        })
+
+#define log_once_errno(level, error, ...)                                \
+        ({                                                               \
+                int _err = (error);                                      \
+                if (ONCE)                                                \
+                        _err = log_full_errno(level, _err, __VA_ARGS__); \
+                else if (LOG_PRI(level) != LOG_DEBUG)                    \
+                        _err = log_debug_errno(_err, __VA_ARGS__);       \
+                else                                                     \
+                        _err = -ERRNO_VALUE(_err);                       \
+                _err;                                                    \
+        })
+
 #if LOG_TRACE
 #  define log_trace(...) log_debug(__VA_ARGS__)
 #else

src/basic/string-util.c

@@ -790,8 +790,8 @@ char *strextend_with_separator_internal(char **x, const char *separator, ...) {
         return p;
 }
 
-int strextendf(char **x, const char *format, ...) {
-        size_t m, a;
+int strextendf_with_separator(char **x, const char *separator, const char *format, ...) {
+        size_t m, a, l_separator;
         va_list ap;
         int l;
 
@@ -802,6 +802,8 @@ int strextendf(char **x, const char *format, ...) {
         assert(x);
         assert(format);
 
+        l_separator = isempty(*x) ? 0 : strlen_ptr(separator);
+
         /* Let's try to use the allocated buffer, if there's room at the end still. Otherwise let's extend by 64 chars. */
         if (*x) {
                 m = strlen(*x);
@@ -810,13 +812,15 @@ int strextendf(char **x, const char *format, ...) {
         } else
                 m = a = 0;
 
-        if (a - m < 17) { /* if there's less than 16 chars space, then enlarge the buffer first */
+        if (a - m < 17 + l_separator) { /* if there's less than 16 chars space, then enlarge the buffer first */
                 char *n;
 
-                if (_unlikely_(m > SIZE_MAX - 64)) /* overflow check */
+                if (_unlikely_(l_separator > SIZE_MAX - 64)) /* overflow check #1 */
+                        return -ENOMEM;
+                if (_unlikely_(m > SIZE_MAX - 64 - l_separator)) /* overflow check #2 */
                         return -ENOMEM;
 
-                n = realloc(*x, m + 64);
+                n = realloc(*x, m + 64 + l_separator);
                 if (!n)
                         return -ENOMEM;
 
@@ -825,19 +829,20 @@ int strextendf(char **x, const char *format, ...) {
         }
 
         /* Now, let's try to format the string into it */
+        memcpy_safe(*x + m, separator, l_separator);
         va_start(ap, format);
-        l = vsnprintf(*x + m, a - m, format, ap);
+        l = vsnprintf(*x + m + l_separator, a - m - l_separator, format, ap);
         va_end(ap);
 
         assert(l >= 0);
 
-        if ((size_t) l < a - m) {
+        if ((size_t) l < a - m - l_separator) {
                 char *n;
 
                 /* Nice! This worked. We are done. But first, let's return the extra space we don't
                  * need. This should be a cheap operation, since we only lower the allocation size here,
                  * never increase. */
-                n = realloc(*x, m + (size_t) l + 1);
+                n = realloc(*x, m + (size_t) l + l_separator + 1);
                 if (n)
                         *x = n;
         } else {
@@ -845,22 +850,22 @@ int strextendf(char **x, const char *format, ...) {
 
                 /* Wasn't enough. Then let's allocate exactly what we need. */
 
-                if (_unlikely_((size_t) l > SIZE_MAX - 1)) /* overflow check #1 */
+                if (_unlikely_((size_t) l > SIZE_MAX - (l_separator + 1))) /* overflow check #1 */
                         goto oom;
-                if (_unlikely_(m > SIZE_MAX - ((size_t) l + 1))) /* overflow check #2 */
+                if (_unlikely_(m > SIZE_MAX - ((size_t) l + l_separator + 1))) /* overflow check #2 */
                         goto oom;
 
-                a = m + (size_t) l + 1;
+                a = m + (size_t) l + l_separator + 1;
                 n = realloc(*x, a);
                 if (!n)
                         goto oom;
                 *x = n;
 
                 va_start(ap, format);
-                l = vsnprintf(*x + m, a - m, format, ap);
+                l = vsnprintf(*x + m + l_separator, a - m - l_separator, format, ap);
                 va_end(ap);
 
-                assert((size_t) l < a - m);
+                assert((size_t) l < a - m - l_separator);
         }
 
         return 0;

src/basic/string-util.h

@@ -156,11 +156,11 @@ char *strreplace(const char *text, const char *old_string, const char *new_strin
 char *strip_tab_ansi(char **ibuf, size_t *_isz, size_t highlight[2]);
 
 char *strextend_with_separator_internal(char **x, const char *separator, ...) _sentinel_;
-
 #define strextend_with_separator(x, separator, ...) strextend_with_separator_internal(x, separator, __VA_ARGS__, NULL)
 #define strextend(x, ...) strextend_with_separator_internal(x, NULL, __VA_ARGS__, NULL)
 
-int strextendf(char **x, const char *format, ...) _printf_(2,3);
+int strextendf_with_separator(char **x, const char *separator, const char *format, ...) _printf_(3,4);
+#define strextendf(x, ...) strextendf_with_separator(x, NULL, __VA_ARGS__)
 
 char *strrep(const char *s, unsigned n);
 

src/core/dbus-util.c

@@ -181,7 +181,7 @@ int bus_read_mount_options(
                 return r;
 
         while ((r = sd_bus_message_read(message, "(ss)", &partition, &mount_options)) > 0) {
-                _cleanup_free_ char *previous = NULL, *escaped = NULL;
+                _cleanup_free_ char *escaped = NULL;
                 _cleanup_free_ MountOptions *o = NULL;
                 PartitionDesignator partition_designator;
 
@@ -198,9 +198,7 @@ int bus_read_mount_options(
                 if (!escaped)
                         return -ENOMEM;
 
-                previous = TAKE_PTR(format_str);
-                format_str = strjoin(previous, previous ? separator : "", partition, ":", escaped);
-                if (!format_str)
+                if (!strextend_with_separator(&format_str, separator, partition, ":", escaped))
                         return -ENOMEM;
 
                 o = new(MountOptions, 1);

src/escape/escape.c

@@ -188,13 +188,8 @@ static int run(int argc, char *argv[]) {
 
                                 free_and_replace(e, x);
                         } else if (arg_suffix) {
-                                char *x;
-
-                                x = strjoin(e, ".", arg_suffix);
-                                if (!x)
+                                if (!strextend(&e, ".", arg_suffix))
                                         return log_oom();
-
-                                free_and_replace(e, x);
                         }
 
                         break;

src/fundamental/macro-fundamental.h

@@ -50,6 +50,17 @@
 #define UNIQ_T(x, uniq) CONCATENATE(__unique_prefix_, CONCATENATE(x, uniq))
 #define UNIQ __COUNTER__
 
+/* Note that this works differently from pthread_once(): this macro does
+ * not synchronize code execution, i.e. code that is run conditionalized
+ * on this macro will run concurrently to all other code conditionalized
+ * the same way, there's no ordering or completion enforced. */
+#define ONCE __ONCE(UNIQ_T(_once_, UNIQ))
+#define __ONCE(o)                                                       \
+        ({                                                              \
+                static bool (o) = false;                                \
+                __sync_bool_compare_and_swap(&(o), false, true);        \
+        })
+
 #undef MAX
 #define MAX(a, b) __MAX(UNIQ, (a), UNIQ, (b))
 #define __MAX(aq, a, bq, b)                             \

src/libsystemd/sd-bus/sd-bus.c

@@ -1574,18 +1574,12 @@ int bus_set_address_machine(sd_bus *b, bool user, const char *machine) {
                         return -ENOMEM;
 
                 if (user) {
-                        char *k;
-
                         /* Ideally we'd use the "--user" switch to systemd-stdio-bridge here, but it's only
                          * available in recent systemd versions. Using the "-p" switch with the explicit path
                          * is a working alternative, and is compatible with older versions, hence that's what
                          * we use here. */
-
-                        k = strjoin(a, ",argv7=-punix:path%3d%24%7bXDG_RUNTIME_DIR%7d/bus");
-                        if (!k)
+                        if (!strextend(&a, ",argv7=-punix:path%3d%24%7bXDG_RUNTIME_DIR%7d/bus"))
                                 return -ENOMEM;
-
-                        free_and_replace(a, k);
                 }
         } else {
                 _cleanup_free_ char *e = NULL;

src/libsystemd/sd-device/sd-device.c

@@ -244,71 +244,103 @@ _public_ int sd_device_new_from_devnum(sd_device **ret, char type, dev_t devnum)
         return sd_device_new_from_syspath(ret, syspath);
 }
 
-_public_ int sd_device_new_from_subsystem_sysname(sd_device **ret, const char *subsystem, const char *sysname) {
-        char syspath[PATH_MAX], *name;
+static int device_strjoin_new(
+                const char *a,
+                const char *b,
+                const char *c,
+                const char *d,
+                sd_device **ret) {
+
+        const char *p;
+        int r;
+
+        p = strjoina(a, b, c, d);
+        if (access(p, F_OK) < 0)
+                return IN_SET(errno, ENOENT, ENAMETOOLONG) ? 0 : -errno; /* If this sysfs is too long then it doesn't exist either */
+
+        r = sd_device_new_from_syspath(ret, p);
+        if (r < 0)
+                return r;
+
+        return 1;
+}
+
+_public_ int sd_device_new_from_subsystem_sysname(
+                sd_device **ret,
+                const char *subsystem,
+                const char *sysname) {
+
+        const char *s;
+        char *name;
+        int r;
 
         assert_return(ret, -EINVAL);
-        assert_return(subsystem, -EINVAL);
-        assert_return(sysname, -EINVAL);
-        assert_return(strlen(sysname) < PATH_MAX - strlen("/sys/bus/"), -ENAMETOOLONG);
+        assert_return(path_is_normalized(subsystem), -EINVAL);
+        assert_return(path_is_normalized(sysname), -EINVAL);
 
         if (streq(subsystem, "subsystem")) {
-                if (snprintf_ok(syspath, sizeof syspath, "/sys/subsystem/%s", sysname) &&
-                    access(syspath, F_OK) >= 0)
-                        return sd_device_new_from_syspath(ret, syspath);
 
-                if (snprintf_ok(syspath, sizeof syspath, "/sys/bus/%s", sysname) &&
-                    access(syspath, F_OK) >= 0)
-                        return sd_device_new_from_syspath(ret, syspath);
-
-                if (snprintf_ok(syspath, sizeof syspath, "/sys/class/%s", sysname) &&
-                    access(syspath, F_OK) >= 0)
-                        return sd_device_new_from_syspath(ret, syspath);
+                FOREACH_STRING(s, "/sys/subsystem/", "/sys/bus/", "/sys/class/") {
+                        r = device_strjoin_new(s, sysname, NULL, NULL, ret);
+                        if (r < 0)
+                                return r;
+                        if (r > 0)
+                                return 0;
+                }
 
         } else  if (streq(subsystem, "module")) {
-                if (snprintf_ok(syspath, sizeof syspath, "/sys/module/%s", sysname) &&
-                    access(syspath, F_OK) >= 0)
-                        return sd_device_new_from_syspath(ret, syspath);
+
+                r = device_strjoin_new("/sys/module/", sysname, NULL, NULL, ret);
+                if (r < 0)
+                        return r;
+                if (r > 0)
+                        return 0;
 
         } else if (streq(subsystem, "drivers")) {
-                const char *subsys, *sep;
+                const char *sep;
 
                 sep = strchr(sysname, ':');
                 if (sep && sep[1] != '\0') { /* Require ":" and something non-empty after that. */
+                        const char *subsys;
+
                         subsys = memdupa_suffix0(sysname, sep - sysname);
+                        sep++;
 
-                        if (snprintf_ok(syspath, sizeof syspath, "/sys/subsystem/%s/drivers/%s", subsys, sep + 1) &&
-                            access(syspath, F_OK) >= 0)
-                                return sd_device_new_from_syspath(ret, syspath);
-
-                        if (snprintf_ok(syspath, sizeof syspath, "/sys/bus/%s/drivers/%s", subsys, sep + 1) &&
-                            access(syspath, F_OK) >= 0)
-                                return sd_device_new_from_syspath(ret, syspath);
+                        FOREACH_STRING(s, "/sys/subsystem/", "/sys/bus/") {
+                                r = device_strjoin_new(s, subsys, "/drivers/", sep, ret);
+                                if (r < 0)
+                                        return r;
+                                if (r > 0)
+                                        return 0;
+                        }
                 }
         }
 
         /* translate sysname back to sysfs filename */
         name = strdupa(sysname);
-
         for (size_t i = 0; name[i]; i++)
                 if (name[i] == '/')
                         name[i] = '!';
 
-        if (snprintf_ok(syspath, sizeof syspath, "/sys/subsystem/%s/devices/%s", subsystem, name) &&
-            access(syspath, F_OK) >= 0)
-                return sd_device_new_from_syspath(ret, syspath);
+        FOREACH_STRING(s, "/sys/subsystem/", "/sys/bus/") {
+                r = device_strjoin_new(s, subsystem, "/devices/", name, ret);
+                if (r < 0)
+                        return r;
+                if (r > 0)
+                        return 0;
+        }
 
-        if (snprintf_ok(syspath, sizeof syspath, "/sys/bus/%s/devices/%s", subsystem, name) &&
-            access(syspath, F_OK) >= 0)
-                return sd_device_new_from_syspath(ret, syspath);
+        r = device_strjoin_new("/sys/class/", subsystem, "/", name, ret);
+        if (r < 0)
+                return r;
+        if (r > 0)
+                return 0;
 
-        if (snprintf_ok(syspath, sizeof syspath, "/sys/class/%s/%s", subsystem, name) &&
-            access(syspath, F_OK) >= 0)
-                return sd_device_new_from_syspath(ret, syspath);
-
-        if (snprintf_ok(syspath, sizeof syspath, "/sys/firmware/%s/%s", subsystem, sysname) &&
-            access(syspath, F_OK) >= 0)
-                return sd_device_new_from_syspath(ret, syspath);
+        r = device_strjoin_new("/sys/firmware/", subsystem, "/", sysname, ret);
+        if (r < 0)
+                return r;
+        if (r > 0)
+                return 0;
 
         return -ENODEV;
 }

src/libsystemd/sd-journal/journal-vacuum.c

@@ -206,6 +206,9 @@ int journal_directory_vacuum(
                 } else if (endswith(de->d_name, ".journal~")) {
                         unsigned long long tmp;
 
+                        /* seqnum_id won't be initialised before use below, so set to 0 */
+                        seqnum_id = SD_ID128_NULL;
+
                         /* Vacuum corrupted files */
 
                         if (q < 1 + 16 + 1 + 16 + 8 + 1) {

src/network/networkctl.c

@@ -1046,26 +1046,25 @@ static int dump_gateways(
                 return n;
 
         for (int i = 0; i < n; i++) {
-                _cleanup_free_ char *gateway = NULL, *description = NULL, *with_description = NULL;
+                _cleanup_free_ char *gateway = NULL, *description = NULL;
                 char name[IF_NAMESIZE+1];
 
                 r = in_addr_to_string(local[i].family, &local[i].address, &gateway);
                 if (r < 0)
-                        return r;
+                        return log_oom();
 
                 r = get_gateway_description(rtnl, hwdb, local[i].ifindex, local[i].family, &local[i].address, &description);
                 if (r < 0)
                         log_debug_errno(r, "Could not get description of gateway, ignoring: %m");
 
                 if (description) {
-                        with_description = strjoin(gateway, " (", description, ")");
-                        if (!with_description)
+                        if (!strextend(&gateway, " (", description, ")"))
                                 return log_oom();
                 }
 
                 /* Show interface name for the entry if we show entries for all interfaces */
                 r = strv_extendf(&buf, "%s%s%s",
-                                 with_description ?: gateway,
+                                 gateway,
                                  ifindex <= 0 ? " on " : "",
                                  ifindex <= 0 ? format_ifname_full(local[i].ifindex, name, FORMAT_IFNAME_IFINDEX_WITH_PERCENT) : "");
                 if (r < 0)

src/network/networkd-route.c

@@ -773,13 +773,17 @@ static void log_route_debug(const Route *route, const char *str, const Link *lin
                 MultipathRoute *m;
 
                 ORDERED_SET_FOREACH(m, route->multipath_routes) {
-                        _cleanup_free_ char *buf = NULL, *joined = NULL;
+                        _cleanup_free_ char *buf = NULL;
                         union in_addr_union a = m->gateway.address;
 
                         (void) in_addr_to_string(m->gateway.family, &a, &buf);
-                        joined = strjoin(gw_alloc, gw_alloc ? "," : "", strna(buf), m->ifname ? "@" : "", strempty(m->ifname));
-                        if (joined)
-                                free_and_replace(gw_alloc, joined);
+                        (void) strextend_with_separator(&gw_alloc, ",", strna(buf));
+                        if (m->ifname)
+                                (void) strextend(&gw_alloc, "@", m->ifname);
+                        else if (m->ifindex > 0)
+                                (void) strextendf(&gw_alloc, "@%"PRIu32, m->ifindex);
+                        /* See comments in config_parse_multipath_route(). */
+                        (void) strextendf(&gw_alloc, ":%"PRIu32, m->weight + 1);
                 }
                 gw = gw_alloc;
         }

src/nspawn/nspawn-mount.c

@@ -382,39 +382,28 @@ int tmpfs_patch_options(
                 const char *selinux_apifs_context,
                 char **ret) {
 
-        char *buf = NULL;
+        _cleanup_free_ char *buf = NULL;
 
-        if (uid_shift != UID_INVALID) {
-                if (asprintf(&buf, "%s%suid=" UID_FMT ",gid=" UID_FMT,
-                             strempty(options), options ? "," : "",
-                             uid_shift, uid_shift) < 0)
-                        return -ENOMEM;
+        assert(ret);
 
-                options = buf;
-        }
-
-#if HAVE_SELINUX
-        if (selinux_apifs_context) {
-                char *t;
-
-                t = strjoin(strempty(options), options ? "," : "",
-                            "context=\"", selinux_apifs_context, "\"");
-                free(buf);
-                if (!t)
-                        return -ENOMEM;
-
-                buf = t;
-        }
-#endif
-
-        if (!buf && options) {
+        if (options) {
                 buf = strdup(options);
                 if (!buf)
                         return -ENOMEM;
         }
-        *ret = buf;
 
-        return !!buf;
+        if (uid_shift != UID_INVALID)
+                if (strextendf_with_separator(&buf, ",", "uid=" UID_FMT ",gid=" UID_FMT, uid_shift, uid_shift) < 0)
+                        return -ENOMEM;
+
+#if HAVE_SELINUX
+        if (selinux_apifs_context)
+                if (!strextend_with_separator(&buf, ",", "context=\"", selinux_apifs_context, "\""))
+                        return -ENOMEM;
+#endif
+
+        *ret = TAKE_PTR(buf);
+        return !!*ret;
 }
 
 int mount_sysfs(const char *dest, MountSettingsMask mount_settings) {

src/oom/oomd-util.c

@@ -333,7 +333,11 @@ int oomd_cgroup_context_acquire(const char *path, OomdCGroupContext **ret) {
                         return log_debug_errno(r, "Error getting memory.low from %s: %m", path);
 
                 r = cg_get_attribute_as_uint64(SYSTEMD_CGROUP_CONTROLLER, path, "memory.swap.current", &ctx->swap_usage);
-                if (r < 0)
+                if (r == -ENODATA)
+                        /* The kernel can be compiled without support for memory.swap.* files,
+                         * or it can be disabled with boot param 'swapaccount=0' */
+                        log_once(LOG_WARNING, "No kernel support for memory.swap.current from %s (try boot param swapaccount=1), ignoring.", path);
+                else if (r < 0)
                         return log_debug_errno(r, "Error getting memory.swap.current from %s: %m", path);
 
                 r = cg_get_keyed_attribute(SYSTEMD_CGROUP_CONTROLLER, path, "memory.stat", STRV_MAKE("pgscan"), &val);

src/resolve/resolved-dns-dnssec.c

@@ -805,7 +805,9 @@ int dnssec_verify_rrset(
         case DNSSEC_ALGORITHM_ED448:
                 *result = DNSSEC_UNSUPPORTED_ALGORITHM;
                 return 0;
-        default:
+        default: {
+                gcry_error_t err;
+
                 /* OK, the RRs are now in canonical order. Let's calculate the digest */
                 md_algorithm = algorithm_to_gcrypt_md(rrsig->rrsig.algorithm);
                 if (md_algorithm == -EOPNOTSUPP) {
@@ -815,8 +817,8 @@ int dnssec_verify_rrset(
                 if (md_algorithm < 0)
                         return md_algorithm;
 
-                gcry_md_open(&md, md_algorithm, 0);
-                if (!md)
+                err = gcry_md_open(&md, md_algorithm, 0);
+                if (gcry_err_code(err) != GPG_ERR_NO_ERROR || !md)
                         return -EIO;
 
                 hash_size = gcry_md_get_algo_dlen(md_algorithm);
@@ -828,6 +830,7 @@ int dnssec_verify_rrset(
                 if (!hash)
                         return -EIO;
         }
+        }
 
         switch (rrsig->rrsig.algorithm) {
 

src/run/run.c

@@ -667,15 +667,8 @@ static int transient_cgroup_set_properties(sd_bus_message *m) {
                 *end = 0;
         }
 
-        if (!isempty(arg_slice)) {
-                if (name) {
-                        char *j = strjoin(name, "-", arg_slice);
-                        free_and_replace(name, j);
-                } else
-                        name = strdup(arg_slice);
-                if (!name)
-                        return log_oom();
-        }
+        if (!isempty(arg_slice) && !strextend_with_separator(&name, "-", arg_slice))
+                return log_oom();
 
         if (!name)
                 return 0;

src/shared/psi-util.c

@@ -4,6 +4,7 @@
 #include <unistd.h>
 
 #include "alloc-util.h"
+#include "errno-util.h"
 #include "extract-word.h"
 #include "fd-util.h"
 #include "fileio.h"
@@ -107,12 +108,18 @@ int read_resource_pressure(const char *path, PressureType type, ResourcePressure
 int is_pressure_supported(void) {
         const char *p;
 
-        FOREACH_STRING(p, "/proc/pressure/cpu", "/proc/pressure/io", "/proc/pressure/memory")
-                if (access(p, F_OK) < 0) {
-                        if (errno == ENOENT)
-                                return 0;
-                        return -errno;
-                }
+        /* The pressure files, both under /proc and in cgroups, will exist
+         * even if the kernel has PSI support disabled; we have to read
+         * the file to make sure it doesn't return -EOPNOTSUPP */
+        FOREACH_STRING(p, "/proc/pressure/cpu", "/proc/pressure/io", "/proc/pressure/memory") {
+                int r;
+
+                r = read_virtual_file(p, 0, NULL, NULL);
+                if (r == -ENOENT || ERRNO_IS_NOT_SUPPORTED(r))
+                        return 0;
+                if (r < 0)
+                        return r;
+        }
 
         return 1;
 }

src/systemctl/systemctl-show.c

@@ -1659,14 +1659,9 @@ static int print_property(const char *name, const char *expected_value, sd_bus_m
                                 if (r < 0)
                                         return r;
 
-                                while ((r = sd_bus_message_read(m, "(ss)", &partition, &mount_options)) > 0) {
-                                        _cleanup_free_ char *previous = NULL;
-
-                                        previous = TAKE_PTR(str);
-                                        str = strjoin(strempty(previous), previous ? ":" : "", partition, ":", mount_options);
-                                        if (!str)
+                                while ((r = sd_bus_message_read(m, "(ss)", &partition, &mount_options)) > 0)
+                                        if (!strextend_with_separator(&str, ":", partition, ":", mount_options))
                                                 return log_oom();
-                                }
                                 if (r < 0)
                                         return r;
 

src/sysv-generator/sysv-generator.c

@@ -533,7 +533,7 @@ static int load_sysv(SysvStub *s) {
                          * continuation */
 
                         size_t k;
-                        char *j;
+                        const char *j;
 
                         k = strlen(t);
                         if (k > 0 && t[k-1] == '\\')
@@ -542,19 +542,8 @@ static int load_sysv(SysvStub *s) {
                                 state = NORMAL;
 
                         j = strstrip(t);
-                        if (!isempty(j)) {
-                                char *d = NULL;
-
-                                if (chkconfig_description)
-                                        d = strjoin(chkconfig_description, " ", j);
-                                else
-                                        d = strdup(j);
-                                if (!d)
-                                        return log_oom();
-
-                                free(chkconfig_description);
-                                chkconfig_description = d;
-                        }
+                        if (!isempty(j) && !strextend_with_separator(&chkconfig_description, " ", j))
+                                return log_oom();
 
                 } else if (IN_SET(state, LSB, LSB_DESCRIPTION)) {
 
@@ -604,20 +593,8 @@ static int load_sysv(SysvStub *s) {
                                         const char *j;
 
                                         j = strstrip(t);
-                                        if (!isempty(j)) {
-                                                char *d = NULL;
-
-                                                if (long_description)
-                                                        d = strjoin(long_description, " ", t);
-                                                else
-                                                        d = strdup(j);
-                                                if (!d)
-                                                        return log_oom();
-
-                                                free(long_description);
-                                                long_description = d;
-                                        }
-
+                                        if (!isempty(j) && !strextend_with_separator(&long_description, " ", j))
+                                                return log_oom();
                                 } else
                                         state = LSB;
                         }

src/test/test-string-util.c

@@ -984,6 +984,20 @@ static void test_strextendf(void) {
 
         assert_se(strextendf(&p, "<%08x>", 0x1234) >= 0);
         assert_se(streq(p, "<77><99><                                                                              88><00001234>"));
+
+        p = mfree(p);
+
+        assert_se(strextendf_with_separator(&p, ",", "<%i>", 77) >= 0);
+        assert_se(streq(p, "<77>"));
+
+        assert_se(strextendf_with_separator(&p, ",", "<%i>", 99) >= 0);
+        assert_se(streq(p, "<77>,<99>"));
+
+        assert_se(strextendf_with_separator(&p, ",", "<%80i>", 88) >= 0);
+        assert_se(streq(p, "<77>,<99>,<                                                                              88>"));
+
+        assert_se(strextendf_with_separator(&p, ",", "<%08x>", 0x1234) >= 0);
+        assert_se(streq(p, "<77>,<99>,<                                                                              88>,<00001234>"));
 }
 
 int main(int argc, char *argv[]) {

src/test/test-udev-util.c

@@ -252,7 +252,7 @@ static void test_udev_resolve_subsys_kernel(void) {
         test_udev_resolve_subsys_kernel_one("hoge", false, -EINVAL, NULL);
         test_udev_resolve_subsys_kernel_one("[hoge", false, -EINVAL, NULL);
         test_udev_resolve_subsys_kernel_one("[hoge/foo", false, -EINVAL, NULL);
-        test_udev_resolve_subsys_kernel_one("[hoge/]", false, -ENODEV, NULL);
+        test_udev_resolve_subsys_kernel_one("[hoge/]", false, -EINVAL, NULL);
 
         test_udev_resolve_subsys_kernel_one("[net/lo]", false, 0, "/sys/devices/virtual/net/lo");
         test_udev_resolve_subsys_kernel_one("[net/lo]/", false, 0, "/sys/devices/virtual/net/lo");