network: a couple of tweaks suggested by Coccinelle

Follow-up for b55093ce8884ee4fc72f28c6fd5e39897e921e21.

man/machine-info.xml

@@ -136,7 +136,8 @@
         <command>kernel-install</command> should use. The value must be a valid machine ID (32 hexadecimal
         characters). This would generally be the original machine-id that was used when the boot loader
         entries for this installation were first added. When not set, the current value of
-        <cite>machine-id(5)</cite> will be used.</para></listitem>
+        <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+        will be used.</para></listitem>
       </varlistentry>
     </variablelist>
   </refsect1>

man/sd_journal_next.xml

@@ -80,7 +80,7 @@
     <para><function>sd_journal_next_skip()</function> and
     <function>sd_journal_previous_skip()</function> advance/set back the read pointer by multiple
     entries at once, as specified in the <varname>skip</varname> parameter. The <varname>skip</varname>
-    parameter must be less than or equal to 2147483647 (2^31-1).</para>
+    parameter must be less than or equal to 2147483647 (2³¹-1).</para>
 
     <para>The journal is strictly ordered by reception time, and hence
     advancing to the next entry guarantees that the entry then

man/systemd-journald.service.xml

@@ -71,7 +71,7 @@
     </para>
 
     <para>Log data collected by the journal is primarily text-based but can also include binary data where
-    necessary. Individual fields making up a log record stored in the journal may be up to 2^64-1 bytes in size.</para>
+    necessary. Individual fields making up a log record stored in the journal may be up to 2⁶⁴-1 bytes in size.</para>
 
     <para>The journal service stores log data either persistently below <filename>/var/log/journal</filename> or in a
     volatile way below <filename>/run/log/journal/</filename> (in the latter case it is lost at reboot). By default, log

man/systemd.net-naming-scheme.xml

@@ -384,10 +384,10 @@
           numbers, which could either result in an incorrect value of the <varname>ID_NET_NAME_SLOT</varname>
           property or none at all.</para>
 
-          <para>Some firmware and hypervisor implementations report unreasonable high numbers for the onboard
+          <para>Some firmware and hypervisor implementations report unreasonably high numbers for the onboard
           index. To prevent the generation of bogus onbard interface names, index numbers greater than 16381
-          (2^14-1) were ignored. For s390 PCI devices index values up to 65535 (2^16-1) are valid. To account
-          for that, the limit is increased to now 65535.</para>
+          (2¹⁴-1) were ignored. For s390 PCI devices index values up to 65535 (2¹⁶-1) are valid. To account
+          for that, the limit was increased to 65535.</para>
 
           <para>The udev rule <varname>NAME=</varname> replaces <literal>:</literal>,
           <literal>/</literal>, and <literal>%</literal> with an underscore (<literal>_</literal>), and

src/basic/string-util.h

@@ -60,6 +60,10 @@ static inline const char *empty_to_null(const char *p) {
         return isempty(p) ? NULL : p;
 }
 
+static inline const char *empty_to_na(const char *p) {
+        return isempty(p) ? "n/a" : p;
+}
+
 static inline const char *empty_to_dash(const char *str) {
         return isempty(str) ? "-" : str;
 }

src/network/netdev/ipoib.c

@@ -139,7 +139,7 @@ int config_parse_ipoib_pkey(
                            rvalue);
                 return 0;
         }
-        if (u == 0 || u == 0x8000) {
+        if (IN_SET(u, 0, 0x8000)) {
                 log_syntax(unit, LOG_WARNING, filename, line, 0,
                            "IPoIB pkey cannot be 0 nor 0x8000, ignoring assignment: %s",
                            rvalue);

src/network/networkd-address-generation.c

@@ -358,10 +358,9 @@ int config_parse_address_generation_type(
 
                                 addr = addr_alloc;
                         }
-                } else if (*addr == ',') {
-                        comma = addr;
-                        addr = NULL;
-                } else if (*addr == '\0') {
+                } else if (*addr == ',')
+                        comma = TAKE_PTR(addr);
+                else if (*addr == '\0') {
                         comma = NULL;
                         addr = NULL;
                 } else {

src/network/networkd-dhcp4.c

@@ -1528,7 +1528,7 @@ static int dhcp4_configure(Link *link) {
                         return log_link_debug_errno(link, r, "DHCPv4 CLIENT: Failed to set max attempts: %m");
         }
 
-        if (link->network->dhcp_ip_service_type > 0) {
+        if (link->network->dhcp_ip_service_type >= 0) {
                 r = sd_dhcp_client_set_service_type(link->dhcp_client, link->network->dhcp_ip_service_type);
                 if (r < 0)
                         return log_link_debug_errno(link, r, "DHCPv4 CLIENT: Failed to set IP service type: %m");

src/udev/udev-builtin-net_id.c

@@ -176,27 +176,33 @@ static int dev_pci_onboard(sd_device *dev, const LinkInfo *info, NetNames *names
         assert(names);
 
         /* ACPI _DSM — device specific method for naming a PCI or PCI Express device */
-        if (sd_device_get_sysattr_value(names->pcidev, "acpi_index", &attr) < 0) {
+        if (sd_device_get_sysattr_value(names->pcidev, "acpi_index", &attr) >= 0)
+                log_device_debug(names->pcidev, "acpi_index=%s", attr);
+        else {
                 /* SMBIOS type 41 — Onboard Devices Extended Information */
                 r = sd_device_get_sysattr_value(names->pcidev, "index", &attr);
                 if (r < 0)
                         return r;
+                log_device_debug(names->pcidev, "index=%s", attr);
         }
 
         r = safe_atolu(attr, &idx);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(names->pcidev, r,
+                                              "Failed to parse onboard index \"%s\": %m", attr);
         if (idx == 0 && !naming_scheme_has(NAMING_ZERO_ACPI_INDEX))
-                return -EINVAL;
-
+                return log_device_debug_errno(names->pcidev, SYNTHETIC_ERRNO(EINVAL),
+                                              "Naming scheme does not allow onboard index==0.");
         if (!is_valid_onboard_index(idx))
-                return -ENOENT;
+                return log_device_debug_errno(names->pcidev, SYNTHETIC_ERRNO(ENOENT),
+                                              "Not a valid onboard index: %lu", idx);
 
         /* kernel provided port index for multiple ports on a single PCI function */
         if (sd_device_get_sysattr_value(dev, "dev_port", &attr) >= 0) {
                 r = safe_atolu_full(attr, 10, &dev_port);
                 if (r < 0)
                         log_device_debug_errno(dev, r, "Failed to parse dev_port, ignoring: %m");
+                log_device_debug(dev, "dev_port=%lu", dev_port);
         }
 
         s = names->pci_onboard;
@@ -209,8 +215,13 @@ static int dev_pci_onboard(sd_device *dev, const LinkInfo *info, NetNames *names
                 l = strpcpyf(&s, l, "d%lu", dev_port);
         if (l == 0)
                 names->pci_onboard[0] = '\0';
+        log_device_debug(dev, "Onboard index identifier: index=%lu phys_port=%s dev_port=%lu → %s",
+                         idx, strempty(info->phys_port_name), dev_port,
+                         empty_to_na(names->pci_slot));
 
-        if (sd_device_get_sysattr_value(names->pcidev, "label", &names->pci_onboard_label) < 0)
+        if (sd_device_get_sysattr_value(names->pcidev, "label", &names->pci_onboard_label) >= 0)
+                log_device_debug(dev, "Onboard label from PCI device: %s", names->pci_onboard_label);
+        else
                 names->pci_onboard_label = NULL;
 
         return 0;
@@ -261,7 +272,10 @@ static bool is_pci_bridge(sd_device *dev) {
                 return false;
 
         /* PCI device subclass 04 corresponds to PCI bridge */
-        return strneq(p + 2, "04", 2);
+        bool b = strneq(p + 2, "04", 2);
+        if (b)
+                log_device_debug(dev, "Device is a PCI bridge.");
+        return b;
 }
 
 static int parse_hotplug_slot_from_function_id(sd_device *dev, const char *slots, uint32_t *ret) {
@@ -326,9 +340,12 @@ static int dev_pci_slot(sd_device *dev, const LinkInfo *info, NetNames *names) {
 
         r = sd_device_get_sysname(names->pcidev, &sysname);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(names->pcidev, r, "Failed to get sysname: %m");
 
-        if (sscanf(sysname, "%x:%x:%x.%u", &domain, &bus, &slot, &func) != 4)
+        r = sscanf(sysname, "%x:%x:%x.%u", &domain, &bus, &slot, &func);
+        log_device_debug(dev, "Parsing slot information from PCI device sysname \"%s\": %s",
+                         sysname, r == 4 ? "success" : "failure");
+        if (r != 4)
                 return -ENOENT;
 
         if (naming_scheme_has(NAMING_NPAR_ARI) &&
@@ -340,6 +357,8 @@ static int dev_pci_slot(sd_device *dev, const LinkInfo *info, NetNames *names) {
 
         /* kernel provided port index for multiple ports on a single PCI function */
         if (sd_device_get_sysattr_value(dev, "dev_port", &attr) >= 0) {
+                log_device_debug(dev, "dev_port=%s", attr);
+
                 r = safe_atolu_full(attr, 10, &dev_port);
                 if (r < 0)
                         log_device_debug_errno(dev, r, "Failed to parse attribute dev_port, ignoring: %m");
@@ -350,6 +369,8 @@ static int dev_pci_slot(sd_device *dev, const LinkInfo *info, NetNames *names) {
                 if (dev_port == 0 &&
                     info->iftype == ARPHRD_INFINIBAND &&
                     sd_device_get_sysattr_value(dev, "dev_id", &attr) >= 0) {
+                        log_device_debug(dev, "dev_id=%s", attr);
+
                         r = safe_atolu_full(attr, 10, &dev_port);
                         if (r < 0)
                                 log_device_debug_errno(dev, r, "Failed to parse attribute dev_id, ignoring: %m");
@@ -372,20 +393,26 @@ static int dev_pci_slot(sd_device *dev, const LinkInfo *info, NetNames *names) {
         if (l == 0)
                 names->pci_path[0] = '\0';
 
+        log_device_debug(dev, "PCI path identifier: domain=%u bus=%u slot=%u func=%u phys_port=%s dev_port=%lu → %s",
+                         domain, bus, slot, func, strempty(info->phys_port_name), dev_port,
+                         empty_to_na(names->pci_path));
+
         /* ACPI _SUN — slot user number */
         r = sd_device_new_from_subsystem_sysname(&pci, "subsystem", "pci");
         if (r < 0)
-                return r;
+                return log_debug_errno(r, "sd_device_new_from_subsystem_sysname failed: %m");
 
         r = sd_device_get_syspath(pci, &syspath);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(pci, r, "sd_device_get_syspath failed: %m");
+
         if (!snprintf_ok(slots, sizeof slots, "%s/slots", syspath))
-                return -ENAMETOOLONG;
+                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(ENAMETOOLONG),
+                                              "Cannot access %s/slots: %m", syspath);
 
         dir = opendir(slots);
         if (!dir)
-                return -errno;
+                return log_device_debug_errno(dev, errno, "Cannot access %s: %m", slots);
 
         hotplug_slot_dev = names->pcidev;
         while (hotplug_slot_dev) {
@@ -423,8 +450,10 @@ static int dev_pci_slot(sd_device *dev, const LinkInfo *info, NetNames *names) {
                                  * slot index if the device is a PCI bridge, because it can have other child
                                  * devices that will try to claim the same index and that would create name
                                  * collision. */
-                                if (naming_scheme_has(NAMING_BRIDGE_NO_SLOT) && is_pci_bridge(hotplug_slot_dev))
+                                if (naming_scheme_has(NAMING_BRIDGE_NO_SLOT) && is_pci_bridge(hotplug_slot_dev)) {
+                                        log_device_debug(dev, "Not using slot information because the PCI device is a bridge.");
                                         return 0;
+                                }
 
                                 break;
                         }
@@ -440,16 +469,20 @@ static int dev_pci_slot(sd_device *dev, const LinkInfo *info, NetNames *names) {
                 s = names->pci_slot;
                 l = sizeof(names->pci_slot);
                 if (domain > 0)
-                        l = strpcpyf(&s, l, "P%d", domain);
+                        l = strpcpyf(&s, l, "P%u", domain);
                 l = strpcpyf(&s, l, "s%"PRIu32, hotplug_slot);
                 if (func > 0 || is_pci_multifunction(names->pcidev))
-                        l = strpcpyf(&s, l, "f%d", func);
+                        l = strpcpyf(&s, l, "f%u", func);
                 if (!isempty(info->phys_port_name))
                         l = strpcpyf(&s, l, "n%s", info->phys_port_name);
                 else if (dev_port > 0)
                         l = strpcpyf(&s, l, "d%lu", dev_port);
                 if (l == 0)
                         names->pci_slot[0] = '\0';
+
+                log_device_debug(dev, "Slot identifier: domain=%u slot=%"PRIu32" func=%u phys_port=%s dev_port=%lu → %s",
+                                 domain, hotplug_slot, func, strempty(info->phys_port_name), dev_port,
+                                 empty_to_na(names->pci_slot));
         }
 
         return 0;
@@ -464,13 +497,14 @@ static int names_vio(sd_device *dev, NetNames *names) {
         /* check if our direct parent is a VIO device with no other bus in-between */
         r = sd_device_get_parent(dev, &parent);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(dev, r, "sd_device_get_parent failed: %m");
 
         r = sd_device_get_subsystem(parent, &subsystem);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(parent, r, "sd_device_get_subsystem failed: %m");
         if (!streq("vio", subsystem))
                 return -ENOENT;
+        log_device_debug(dev, "Parent device is in the vio subsystem.");
 
         /* The devices' $DEVPATH number is tied to (virtual) hardware (slot id
          * selected in the HMC), thus this provides a reliable naming (e.g.
@@ -478,19 +512,23 @@ static int names_vio(sd_device *dev, NetNames *names) {
          * there should only ever be one bus, and then remove leading zeros. */
         r = sd_device_get_syspath(dev, &syspath);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(dev, r, "sd_device_get_syspath failed: %m");
 
-        if (sscanf(syspath, "/sys/devices/vio/%4x%4x/net/eth%u", &busid, &slotid, &ethid) != 3)
+        r = sscanf(syspath, "/sys/devices/vio/%4x%4x/net/eth%u", &busid, &slotid, &ethid);
+        log_device_debug(dev, "Parsing vio slot information from syspath \"%s\": %s",
+                         syspath, r == 3 ? "success" : "failure");
+        if (r != 3)
                 return -EINVAL;
 
         xsprintf(names->vio_slot, "v%u", slotid);
         names->type = NET_VIO;
+        log_device_debug(dev, "Vio slot identifier: slotid=%u → %s", slotid, names->vio_slot);
         return 0;
 }
 
-#define _PLATFORM_TEST "/sys/devices/platform/vvvvPPPP"
-#define _PLATFORM_PATTERN4 "/sys/devices/platform/%4s%4x:%2x/net/eth%u"
-#define _PLATFORM_PATTERN3 "/sys/devices/platform/%3s%4x:%2x/net/eth%u"
+#define PLATFORM_TEST "/sys/devices/platform/vvvvPPPP"
+#define PLATFORM_PATTERN4 "/sys/devices/platform/%4s%4x:%2x/net/eth%u"
+#define PLATFORM_PATTERN3 "/sys/devices/platform/%3s%4x:%2x/net/eth%u"
 
 static int names_platform(sd_device *dev, NetNames *names, bool test) {
         sd_device *parent;
@@ -502,29 +540,32 @@ static int names_platform(sd_device *dev, NetNames *names, bool test) {
         /* check if our direct parent is a platform device with no other bus in-between */
         r = sd_device_get_parent(dev, &parent);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(dev, r, "sd_device_get_parent failed: %m");
 
         r = sd_device_get_subsystem(parent, &subsystem);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(parent, r, "sd_device_get_subsystem failed: %m");
 
         if (!streq("platform", subsystem))
                  return -ENOENT;
+        log_device_debug(dev, "Parent device is in the platform subsystem.");
 
         r = sd_device_get_syspath(dev, &syspath);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(dev, r, "sd_device_get_syspath failed: %m");
 
         /* syspath is too short, to have a valid ACPI instance */
-        if (strlen(syspath) < sizeof _PLATFORM_TEST)
-                return -EINVAL;
+        if (strlen(syspath) < STRLEN(PLATFORM_TEST) + 1)
+                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EINVAL),
+                                              "Syspath \"%s\" is too short for a valid ACPI instance.",
+                                              syspath);
 
         /* Vendor ID can be either PNP ID (3 chars A-Z) or ACPI ID (4 chars A-Z and numerals) */
-        if (syspath[sizeof _PLATFORM_TEST - 1] == ':') {
-                pattern = _PLATFORM_PATTERN4;
+        if (syspath[STRLEN(PLATFORM_TEST)] == ':') {
+                pattern = PLATFORM_PATTERN4;
                 validchars = UPPERCASE_LETTERS DIGITS;
         } else {
-                pattern = _PLATFORM_PATTERN3;
+                pattern = PLATFORM_PATTERN3;
                 validchars = UPPERCASE_LETTERS;
         }
 
@@ -533,17 +574,23 @@ static int names_platform(sd_device *dev, NetNames *names, bool test) {
          * The Vendor (3 or 4 char), followed by hexadecimal model number : instance id. */
 
         DISABLE_WARNING_FORMAT_NONLITERAL;
-        if (sscanf(syspath, pattern, vendor, &model, &instance, &ethid) != 4)
-                return -EINVAL;
+        r = sscanf(syspath, pattern, vendor, &model, &instance, &ethid);
         REENABLE_WARNING;
+        log_device_debug(dev, "Parsing platform device information from syspath \"%s\": %s",
+                         syspath, r == 4 ? "success" : "failure");
+        if (r != 4)
+                return -EINVAL;
 
         if (!in_charset(vendor, validchars))
-                return -ENOENT;
+                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(ENOENT),
+                                              "Platform vendor contains invalid characters: %s", vendor);
 
         ascii_strlower(vendor);
 
         xsprintf(names->platform_path, "a%s%xi%u", vendor, model, instance);
         names->type = NET_PLATFORM;
+        log_device_debug(dev, "Platform identifier: vendor=%s model=%u instance=%u → %s",
+                         vendor, model, instance, names->platform_path);
         return 0;
 }
 
@@ -619,28 +666,31 @@ static int names_usb(sd_device *dev, NetNames *names) {
 
         r = sd_device_get_parent_with_subsystem_devtype(dev, "usb", "usb_interface", &usbdev);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(dev, r, "sd_device_get_parent_with_subsystem_devtype() failed: %m");
 
         r = sd_device_get_sysname(usbdev, &sysname);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(usbdev, r, "sd_device_get_sysname() failed: %m");
 
         /* get USB port number chain, configuration, interface */
         strscpy(name, sizeof(name), sysname);
         s = strchr(name, '-');
         if (!s)
-                return -EINVAL;
+                return log_device_debug_errno(usbdev, SYNTHETIC_ERRNO(EINVAL),
+                                              "sysname \"%s\" does not have '-' in the expected place.", sysname);
         ports = s+1;
 
         s = strchr(ports, ':');
         if (!s)
-                return -EINVAL;
+                return log_device_debug_errno(usbdev, SYNTHETIC_ERRNO(EINVAL),
+                                              "sysname \"%s\" does not have ':' in the expected place.", sysname);
         s[0] = '\0';
         config = s+1;
 
         s = strchr(config, '.');
         if (!s)
-                return -EINVAL;
+                return log_device_debug_errno(usbdev, SYNTHETIC_ERRNO(EINVAL),
+                                              "sysname \"%s\" does not have '.' in the expected place.", sysname);
         s[0] = '\0';
         interf = s+1;
 
@@ -659,8 +709,10 @@ static int names_usb(sd_device *dev, NetNames *names) {
         if (!streq(interf, "0"))
                 l = strpcpyl(&s, sizeof(names->usb_ports), "i", interf, NULL);
         if (l == 0)
-                return -ENAMETOOLONG;
-
+                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(ENAMETOOLONG),
+                                              "Generated USB name would be too long.");
+        log_device_debug(dev, "USB name identifier: ports=%.*s config=%s interface=%s → %s",
+                         (int) strlen(ports), sysname + (ports - name), config, interf, names->usb_ports);
         names->type = NET_USB;
         return 0;
 }
@@ -676,28 +728,31 @@ static int names_bcma(sd_device *dev, NetNames *names) {
 
         r = sd_device_get_parent_with_subsystem_devtype(dev, "bcma", NULL, &bcmadev);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(dev, r, "sd_device_get_parent_with_subsystem_devtype() failed: %m");
 
         r = sd_device_get_sysname(bcmadev, &sysname);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(dev, r, "sd_device_get_sysname() failed: %m");
 
         /* bus num:core num */
-        if (sscanf(sysname, "bcma%*u:%u", &core) != 1)
+        r = sscanf(sysname, "bcma%*u:%u", &core);
+        log_device_debug(dev, "Parsing bcma device information from sysname \"%s\": %s",
+                         sysname, r == 1 ? "success" : "failure");
+        if (r != 1)
                 return -EINVAL;
         /* suppress the common core == 0 */
         if (core > 0)
                 xsprintf(names->bcma_core, "b%u", core);
 
         names->type = NET_BCMA;
+        log_device_debug(dev, "BCMA core identifier: core=%u → \"%s\"", core, names->bcma_core);
         return 0;
 }
 
 static int names_ccw(sd_device *dev, NetNames *names) {
         sd_device *cdev;
         const char *bus_id, *subsys;
-        size_t bus_id_len;
-        size_t bus_id_start;
+        size_t bus_id_start, bus_id_len;
         int r;
 
         assert(dev);
@@ -706,7 +761,7 @@ static int names_ccw(sd_device *dev, NetNames *names) {
         /* Retrieve the associated CCW device */
         r = sd_device_get_parent(dev, &cdev);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(dev, r, "sd_device_get_parent() failed: %m");
 
         /* skip virtio subsystem if present */
         cdev = skip_virtio(cdev);
@@ -715,11 +770,12 @@ static int names_ccw(sd_device *dev, NetNames *names) {
 
         r = sd_device_get_subsystem(cdev, &subsys);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(cdev, r, "sd_device_get_subsystem() failed: %m");
 
         /* Network devices are either single or grouped CCW devices */
         if (!STR_IN_SET(subsys, "ccwgroup", "ccw"))
                 return -ENOENT;
+        log_device_debug(dev, "Device is CCW.");
 
         /* Retrieve bus-ID of the CCW device.  The bus-ID uniquely
          * identifies the network device on the Linux on System z channel
@@ -727,14 +783,15 @@ static int names_ccw(sd_device *dev, NetNames *names) {
          */
         r = sd_device_get_sysname(cdev, &bus_id);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(cdev, r, "Failed to get sysname: %m");
 
         /* Check the length of the bus-ID. Rely on the fact that the kernel provides a correct bus-ID;
          * alternatively, improve this check and parse and verify each bus-ID part...
          */
         bus_id_len = strlen(bus_id);
         if (!IN_SET(bus_id_len, 8, 9))
-                return -EINVAL;
+                return log_device_debug_errno(cdev, SYNTHETIC_ERRNO(EINVAL),
+                                              "Invalid bus_id: %s", bus_id);
 
         /* Strip leading zeros from the bus id for aesthetic purposes. This
          * keeps the ccw names stable, yet much shorter in general case of
@@ -745,9 +802,11 @@ static int names_ccw(sd_device *dev, NetNames *names) {
         bus_id += bus_id_start < bus_id_len ? bus_id_start : bus_id_len - 1;
 
         /* Store the CCW bus-ID for use as network device name */
-        if (snprintf_ok(names->ccw_busid, sizeof(names->ccw_busid), "c%s", bus_id))
+        if (!snprintf_ok(names->ccw_busid, sizeof(names->ccw_busid), "c%s", bus_id))
+                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(ENAMETOOLONG),
+                                              "Generated CCW name would be too long.");
         names->type = NET_CCW;
-
+        log_device_debug(dev, "CCW identifier: ccw_busid=%s → \"%s\"", bus_id, names->ccw_busid);
         return 0;
 }
 
@@ -762,19 +821,24 @@ static int names_mac(sd_device *dev, const LinkInfo *info) {
         /* The persistent part of a hardware address of an InfiniBand NIC is 8 bytes long. We cannot
          * fit this much in an iface name.
          * TODO: but it can be used as alternative names?? */
-        if (info->iftype == ARPHRD_INFINIBAND || info->hw_addr.length != 6)
-                return -EOPNOTSUPP;
+        if (info->iftype == ARPHRD_INFINIBAND)
+                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EOPNOTSUPP),
+                                              "Not generating MAC name for infiniband device.");
+        if (info->hw_addr.length != 6)
+                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EOPNOTSUPP),
+                                              "Not generating MAC name for device with MAC address of length %zu.",
+                                              info->hw_addr.length);
 
         /* check for NET_ADDR_PERM, skip random MAC addresses */
         r = sd_device_get_sysattr_value(dev, "addr_assign_type", &s);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(dev, r, "Failed to read addr_assign_type: %m");
         r = safe_atou(s, &i);
         if (r < 0)
-                return r;
+                return log_device_debug_errno(dev, r, "Failed to parse addr_assign_type: %m");
         if (i != NET_ADDR_PERM)
-                return -EINVAL;
-
+                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EINVAL),
+                                              "addr_assign_type=%d, MAC address is not permanent.", i);
         return 0;
 }
 
@@ -956,6 +1020,8 @@ static int builtin_net_id(sd_device *dev, sd_netlink **rtnl, int argc, char *arg
 
                 xsprintf(str, "%s%s", prefix, HW_ADDR_TO_STR_FULL(&info.hw_addr, HW_ADDR_TO_STRING_NO_COLON));
                 udev_builtin_add_property(dev, test, "ID_NET_NAME_MAC", str);
+                log_device_debug(dev, "MAC address identifier: hw_addr=%s → %s",
+                                 HW_ADDR_TO_STR(&info.hw_addr), str + strlen(prefix));
 
                 ieee_oui(dev, &info, test);
         }

test/units/testsuite-55-testbloat.service

@@ -5,6 +5,6 @@ Description=Create a lot of memory pressure
 [Service]
 # A VERY small memory.high will cause the script (trying to use a lot of memory)
 # to throttle and be put under heavy pressure.
-MemoryHigh=1M
+MemoryHigh=5M
 Slice=testsuite-55-workload.slice
 ExecStart=/usr/lib/systemd/tests/testdata/units/testsuite-55-slowgrowth.sh

test/units/testsuite-55-testchill.service

@@ -3,5 +3,6 @@
 Description=No memory pressure
 
 [Service]
+MemoryHigh=3M
 Slice=testsuite-55-workload.slice
 ExecStart=sleep infinity

test/units/testsuite-55-testmunch.service

@@ -3,6 +3,6 @@
 Description=Create some memory pressure
 
 [Service]
-MemoryHigh=2M
+MemoryHigh=6M
 Slice=testsuite-55-workload.slice
 ExecStart=/usr/lib/systemd/tests/testdata/units/testsuite-55-slowgrowth.sh