systemctl: show tainted state

Let's make this detectable explicitly.

src/basic/def.h

@@ -73,3 +73,5 @@
 #define VARLINK_ADDR_PATH_MANAGED_OOM_SYSTEM "/run/systemd/io.system.ManagedOOM"
 /* Path where systemd-oomd listens for varlink connections from user managers to report changes in ManagedOOM settings. */
 #define VARLINK_ADDR_PATH_MANAGED_OOM_USER "/run/systemd/oom/io.system.ManagedOOM"
+
+#define KERNEL_BASELINE_VERSION "3.15"

src/basic/virt.c

@@ -12,6 +12,7 @@
 #include "cgroup-util.h"
 #include "dirent-util.h"
 #include "env-util.h"
+#include "errno-util.h"
 #include "fd-util.h"
 #include "fileio.h"
 #include "macro.h"
@@ -791,10 +792,7 @@ int detect_virtualization(void) {
 
 static int userns_has_mapping(const char *name) {
         _cleanup_fclose_ FILE *f = NULL;
-        _cleanup_free_ char *buf = NULL;
-        size_t n_allocated = 0;
-        ssize_t n;
-        uint32_t a, b, c;
+        uid_t a, b, c;
         int r;
 
         f = fopen(name, "re");
@@ -803,19 +801,17 @@ static int userns_has_mapping(const char *name) {
                 return errno == ENOENT ? false : -errno;
         }
 
-        n = getline(&buf, &n_allocated, f);
-        if (n < 0) {
-                if (feof(f)) {
-                        log_debug("%s is empty, we're in an uninitialized user namespace", name);
-                        return true;
-                }
+        errno = 0;
+        r = fscanf(f, UID_FMT " " UID_FMT " " UID_FMT "\n", &a, &b, &c);
+        if (r == EOF) {
+                if (ferror(f))
+                        return log_debug_errno(errno_or_else(EIO), "Failed to read %s: %m", name);
 
-                return log_debug_errno(errno, "Failed to read %s: %m", name);
+                log_debug("%s is empty, we're in an uninitialized user namespace", name);
+                return true;
         }
-
-        r = sscanf(buf, "%"PRIu32" %"PRIu32" %"PRIu32, &a, &b, &c);
-        if (r < 3)
-                return log_debug_errno(errno, "Failed to parse %s: %m", name);
+        if (r != 3)
+                return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Failed to parse %s: %m", name);
 
         if (a == 0 && b == 0 && c == UINT32_MAX) {
                 /* The kernel calls mappings_overlap() and does not allow overlaps */
@@ -840,19 +836,18 @@ int running_in_userns(void) {
         if (r != 0)
                 return r;
 
-        /* "setgroups" file was added in kernel v3.18-rc6-15-g9cc46516dd. It is also
-         * possible to compile a kernel without CONFIG_USER_NS, in which case "setgroups"
-         * also does not exist. We cannot distinguish those two cases, so assume that
-         * we're running on a stripped-down recent kernel, rather than on an old one,
-         * and if the file is not found, return false.
-         */
-        r = read_one_line_file("/proc/self/setgroups", &line);
+        /* "setgroups" file was added in kernel v3.18-rc6-15-g9cc46516dd. It is also possible to compile a
+         * kernel without CONFIG_USER_NS, in which case "setgroups" also does not exist. We cannot
+         * distinguish those two cases, so assume that we're running on a stripped-down recent kernel, rather
+         * than on an old one, and if the file is not found, return false. */
+        r = read_virtual_file("/proc/self/setgroups", SIZE_MAX, &line, NULL);
         if (r < 0) {
                 log_debug_errno(r, "/proc/self/setgroups: %m");
                 return r == -ENOENT ? false : r;
         }
 
-        truncate_nl(line);
+        strstrip(line); /* remove trailing newline */
+
         r = streq(line, "deny");
         /* See user_namespaces(7) for a description of this "setgroups" contents. */
         log_debug("/proc/self/setgroups contains \"%s\", %s user namespace", line, r ? "in" : "not in");

src/core/main.c

@@ -6,6 +6,7 @@
 #include <linux/oom.h>
 #include <sys/mount.h>
 #include <sys/prctl.h>
+#include <sys/utsname.h>
 #include <unistd.h>
 #if HAVE_SECCOMP
 #include <seccomp.h>
@@ -2009,6 +2010,7 @@ static void log_execution_mode(bool *ret_first_boot) {
         assert(ret_first_boot);
 
         if (arg_system) {
+                struct utsname uts;
                 int v;
 
                 log_info("systemd " GIT_VERSION " running in %ssystem mode (%s)",
@@ -2046,6 +2048,14 @@ static void log_execution_mode(bool *ret_first_boot) {
                                 log_debug("Detected initialized system, this is not the first boot.");
                         }
                 }
+
+                assert(uname(&uts) >= 0);
+
+                if (strverscmp_improved(uts.release, KERNEL_BASELINE_VERSION) < 0)
+                        log_warning("Warning! Reported kernel version %s is older than systemd's required baseline kernel version %s. "
+                                    "Your mileage may vary.", uts.release, KERNEL_BASELINE_VERSION);
+                else
+                        log_debug("Kernel version %s, our baseline is %s", uts.release, KERNEL_BASELINE_VERSION);
         } else {
                 if (DEBUG_LOGGING) {
                         _cleanup_free_ char *t = NULL;

src/core/manager.c

@@ -8,6 +8,7 @@
 #include <sys/ioctl.h>
 #include <sys/reboot.h>
 #include <sys/timerfd.h>
+#include <sys/utsname.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
@@ -4351,6 +4352,7 @@ int manager_dispatch_user_lookup_fd(sd_event_source *source, int fd, uint32_t re
 
 char *manager_taint_string(Manager *m) {
         _cleanup_free_ char *destination = NULL, *overflowuid = NULL, *overflowgid = NULL;
+        struct utsname uts;
         char *buf, *e;
         int r;
 
@@ -4367,7 +4369,8 @@ char *manager_taint_string(Manager *m) {
                                "local-hwclock:"
                                "var-run-bad:"
                                "overflowuid-not-65534:"
-                               "overflowgid-not-65534:"));
+                               "overflowgid-not-65534:"
+                               "old-kernel:"));
         if (!buf)
                 return NULL;
 
@@ -4398,6 +4401,10 @@ char *manager_taint_string(Manager *m) {
         if (r >= 0 && !streq(overflowgid, "65534"))
                 e = stpcpy(e, "overflowgid-not-65534:");
 
+        assert_se(uname(&uts) >= 0);
+        if (strverscmp_improved(uts.release, KERNEL_BASELINE_VERSION) < 0)
+                e = stpcpy(e, "old-kernel:");
+
         /* remove the last ':' */
         if (e != buf)
                 e[-1] = 0;

src/systemctl/systemctl-list-machines.c

@@ -15,11 +15,15 @@
 #include "terminal-util.h"
 
 const struct bus_properties_map machine_info_property_map[] = {
-        { "SystemState",        "s", NULL, offsetof(struct machine_info, state)          },
-        { "NJobs",              "u", NULL, offsetof(struct machine_info, n_jobs)         },
-        { "NFailedUnits",       "u", NULL, offsetof(struct machine_info, n_failed_units) },
-        { "ControlGroup",       "s", NULL, offsetof(struct machine_info, control_group)  },
+        /* Might good to keep same order here as in bus_manager_vtable[], server side */
+        { "Version",            "s", NULL, offsetof(struct machine_info, version)        },
+        { "Tainted",            "s", NULL, offsetof(struct machine_info, tainted)        },
         { "UserspaceTimestamp", "t", NULL, offsetof(struct machine_info, timestamp)      },
+        { "NNames",             "u", NULL, offsetof(struct machine_info, n_names)        },
+        { "NFailedUnits",       "u", NULL, offsetof(struct machine_info, n_failed_units) },
+        { "NJobs",              "u", NULL, offsetof(struct machine_info, n_jobs)         },
+        { "ControlGroup",       "s", NULL, offsetof(struct machine_info, control_group)  },
+        { "SystemState",        "s", NULL, offsetof(struct machine_info, state)          },
         {}
 };
 
@@ -27,8 +31,10 @@ void machine_info_clear(struct machine_info *info) {
         assert(info);
 
         free(info->name);
-        free(info->state);
+        free(info->version);
+        free(info->tainted);
         free(info->control_group);
+        free(info->state);
         zero(*info);
 }
 

src/systemctl/systemctl-list-machines.h

@@ -12,11 +12,14 @@ int verb_list_machines(int argc, char *argv[], void *userdata);
 struct machine_info {
         bool is_host;
         char *name;
-        char *state;
-        char *control_group;
+        char *version;
+        char *tainted;
+        uint64_t timestamp;
+        uint32_t n_names;
         uint32_t n_failed_units;
         uint32_t n_jobs;
-        usec_t timestamp;
+        char *control_group;
+        char *state;
 };
 
 void machine_info_clear(struct machine_info *info);

src/systemctl/systemctl-show.c

@@ -2129,6 +2129,7 @@ static int show_system_status(sd_bus *bus) {
         printf("    State: %s%s%s\n",
                on, strna(mi.state), off);
 
+        printf("    Units: %" PRIu32 " loaded (incl. loaded aliases)\n", mi.n_names);
         printf("     Jobs: %" PRIu32 " queued\n", mi.n_jobs);
         printf("   Failed: %" PRIu32 " units\n", mi.n_failed_units);
 
@@ -2136,6 +2137,11 @@ static int show_system_status(sd_bus *bus) {
                FORMAT_TIMESTAMP_STYLE(mi.timestamp, arg_timestamp_style),
                FORMAT_TIMESTAMP_RELATIVE(mi.timestamp));
 
+        printf("  systemd: %s\n", mi.version);
+
+        if (!isempty(mi.tainted))
+                printf("  Tainted: %s%s%s\n", ansi_highlight_yellow(), mi.tainted, ansi_normal());
+
         printf("   CGroup: %s\n", empty_to_root(mi.control_group));
 
         c = LESS_BY(columns(), strlen(prefix));