Merge pull request #26217 from bluca/dump_mem

Add D-Bus method and analyze command to dump malloc_info()

man/systemd-analyze.xml

@@ -139,6 +139,12 @@
       <arg choice="plain">security</arg>
       <arg choice="plain" rep="repeat"><replaceable>UNIT</replaceable></arg>
     </cmdsynopsis>
+    <cmdsynopsis>
+      <command>systemd-analyze</command>
+      <arg choice="opt" rep="repeat">OPTIONS</arg>
+      <arg choice="plain">malloc</arg>
+      <arg choice="opt" rep="repeat"><replaceable>D-BUS SERVICE</replaceable></arg>
+    </cmdsynopsis>
   </refsynopsisdiv>
 
   <refsect1>
@@ -271,6 +277,16 @@ Timestamp units-load-finish: Thu 2019-03-14 23:28:07 CET
       </example>
     </refsect2>
 
+    <refsect2>
+      <title><command>systemd-analyze malloc [<replaceable>D-Bus service</replaceable>…]</command></title>
+
+      <para>This command can be used to request the output of the internal memory state (as returned by
+      <citerefentry><refentrytitle>malloc_info</refentrytitle><manvolnum>3</manvolnum></citerefentry>) of
+      a D-Bus service implementing this pattern. If no service is specified, the command will be sent to
+      <filename>org.freedesktop.systemd1</filename> (the system or user service manager). The output format
+      is subject to change without notice and should not be parsed by applications.</para>
+    </refsect2>
+
     <refsect2>
       <title><command>systemd-analyze plot</command></title>
 

src/analyze/analyze-dump.c

@@ -29,21 +29,6 @@ static int dump_fallback(sd_bus *bus) {
         return 0;
 }
 
-static int dump_fd_reply(sd_bus_message *message) {
-        int fd, r;
-
-        r = sd_bus_message_read(message, "h", &fd);
-        if (r < 0)
-                return bus_log_parse_error(r);
-
-        fflush(stdout);
-        r = copy_bytes(fd, STDOUT_FILENO, UINT64_MAX, 0);
-        if (r < 0)
-                return r;
-
-        return 1;  /* Success */
-}
-
 static int dump(sd_bus *bus) {
         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;

src/analyze/analyze-malloc.c

@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "sd-bus.h"
+
+#include "analyze-malloc.h"
+#include "analyze.h"
+#include "bus-error.h"
+#include "bus-internal.h"
+
+static int dump_malloc_info(sd_bus *bus, char *service) {
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
+        int r;
+
+        assert(bus);
+        assert(service);
+
+        r = sd_bus_call_method(bus,
+                               service,
+                               "/org/freedesktop/MemoryAllocation1",
+                               "org.freedesktop.MemoryAllocation1",
+                               "GetMallocInfo",
+                               &error,
+                               &reply,
+                               NULL);
+        if (r < 0)
+                return log_error_errno(r, "Failed to call GetMallocInfo on '%s': %s", service, bus_error_message(&error, r));
+
+        return dump_fd_reply(reply);
+}
+
+int verb_malloc(int argc, char *argv[], void *userdata) {
+        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+        char **services = STRV_MAKE("org.freedesktop.systemd1");
+        int r;
+
+        if (!strv_isempty(strv_skip(argv, 1))) {
+                services = strv_skip(argv, 1);
+                STRV_FOREACH(service, services)
+                        if (!service_name_is_valid(*service))
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "D-Bus service name '%s' is not valid.", *service);
+        }
+
+        r = acquire_bus(&bus, NULL);
+        if (r < 0)
+                return bus_log_connect_error(r, arg_transport);
+
+        r = sd_bus_can_send(bus, SD_BUS_TYPE_UNIX_FD);
+        if (r < 0)
+                return log_error_errno(r, "Unable to determine if bus connection supports fd passing: %m");
+        if (r == 0)
+                return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Unable to receive FDs over D-Bus.");
+
+        pager_open(arg_pager_flags);
+
+        STRV_FOREACH(service, services) {
+                r = dump_malloc_info(bus, *service);
+                if (r < 0)
+                        return r;
+        }
+
+        return EXIT_SUCCESS;
+}

src/analyze/analyze-malloc.h

@@ -0,0 +1,5 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#pragma once
+
+int verb_malloc(int argc, char *argv[], void *userdata);

src/analyze/analyze.c

@@ -25,6 +25,7 @@
 #include "analyze-filesystems.h"
 #include "analyze-inspect-elf.h"
 #include "analyze-log-control.h"
+#include "analyze-malloc.h"
 #include "analyze-plot.h"
 #include "analyze-security.h"
 #include "analyze-service-watchdogs.h"
@@ -166,6 +167,23 @@ void time_parsing_hint(const char *p, bool calendar, bool timestamp, bool timesp
                            "Use 'systemd-analyze timespan \"%s\"' instead?", p);
 }
 
+int dump_fd_reply(sd_bus_message *message) {
+        int fd, r;
+
+        assert(message);
+
+        r = sd_bus_message_read(message, "h", &fd);
+        if (r < 0)
+                return bus_log_parse_error(r);
+
+        fflush(stdout);
+        r = copy_bytes(fd, STDOUT_FILENO, UINT64_MAX, 0);
+        if (r < 0)
+                return r;
+
+        return 1;  /* Success */
+}
+
 static int help(int argc, char *argv[], void *userdata) {
         _cleanup_free_ char *link = NULL, *dot_link = NULL;
         int r;
@@ -211,6 +229,7 @@ static int help(int argc, char *argv[], void *userdata) {
                "  timespan SPAN...           Validate a time span\n"
                "  security [UNIT...]         Analyze security of unit\n"
                "  inspect-elf FILE...        Parse and print ELF package metadata\n"
+               "  malloc [D-BUS SERVICE...]  Dump malloc stats of a D-Bus service\n"
                "\nOptions:\n"
                "     --recursive-errors=MODE Control which units are verified\n"
                "     --offline=BOOL          Perform a security review on unit file(s)\n"
@@ -601,6 +620,7 @@ static int run(int argc, char *argv[]) {
                 { "timespan",          2,        VERB_ANY, 0,            verb_timespan          },
                 { "security",          VERB_ANY, VERB_ANY, 0,            verb_security          },
                 { "inspect-elf",       2,        VERB_ANY, 0,            verb_elf_inspection    },
+                { "malloc",            VERB_ANY, VERB_ANY, 0,            verb_malloc            },
                 {}
         };
 

src/analyze/analyze.h

@@ -44,3 +44,5 @@ int acquire_bus(sd_bus **bus, bool *use_full_bus);
 int bus_get_unit_property_strv(sd_bus *bus, const char *path, const char *property, char ***strv);
 
 void time_parsing_hint(const char *p, bool calendar, bool timestamp, bool timespan);
+
+int dump_fd_reply(sd_bus_message *message);

src/analyze/meson.build

@@ -14,6 +14,7 @@ systemd_analyze_sources = files(
         'analyze-filesystems.c',
         'analyze-inspect-elf.c',
         'analyze-log-control.c',
+        'analyze-malloc.c',
         'analyze-plot.c',
         'analyze-security.c',
         'analyze-service-watchdogs.c',

src/core/dbus.c

@@ -737,6 +737,10 @@ static int bus_on_connection(sd_event_source *s, int fd, uint32_t revents, void
                 return 0;
         }
 
+        r = bus_register_malloc_status(bus, "org.freedesktop.systemd1");
+        if (r < 0)
+                log_warning_errno(r, "Failed to register MemoryAllocation1, ignoring: %m");
+
         r = set_ensure_put(&m->private_buses, NULL, bus);
         if (r == -ENOMEM) {
                 log_oom();
@@ -798,6 +802,10 @@ static int bus_setup_api(Manager *m, sd_bus *bus) {
         if (r < 0)
                 return log_error_errno(r, "Failed to request name: %m");
 
+        r = bus_register_malloc_status(bus, "org.freedesktop.systemd1");
+        if (r < 0)
+                log_warning_errno(r, "Failed to register MemoryAllocation1, ignoring: %m");
+
         log_debug("Successfully connected to API bus.");
 
         return 0;

src/shared/bus-util.c

@@ -18,6 +18,8 @@
 #include "bus-internal.h"
 #include "bus-label.h"
 #include "bus-util.h"
+#include "data-fd-util.h"
+#include "fd-util.h"
 #include "path-util.h"
 #include "socket-util.h"
 #include "stdio-util.h"
@@ -578,6 +580,62 @@ int bus_reply_pair_array(sd_bus_message *m, char **l) {
         return sd_bus_send(NULL, reply, NULL);
 }
 
+static int method_dump_memory_state_by_fd(sd_bus_message *message, void *userdata, sd_bus_error *ret_error) {
+        _cleanup_free_ char *dump = NULL; /* keep this above dump_file, so that it's freed after */
+        _cleanup_fclose_ FILE *dump_file = NULL;
+        _cleanup_close_ int fd = -EBADF;
+        size_t dump_size;
+        int r;
+
+        assert(message);
+
+        dump_file = open_memstream(&dump, &dump_size);
+        if (!dump_file)
+                return -ENOMEM;
+
+        r = RET_NERRNO(malloc_info(/* options= */ 0, dump_file));
+        if (r < 0)
+                return r;
+
+        dump_file = safe_fclose(dump_file);
+
+        fd = acquire_data_fd(dump, dump_size, 0);
+        if (fd < 0)
+                return fd;
+
+        r = sd_bus_reply_method_return(message, "h", fd);
+        if (r < 0)
+                return r;
+
+        return 1; /* Stop further processing */
+}
+
+/* The default install callback will fail and disconnect the bus if it cannot register the match, but this
+ * is only a debug method, we definitely don't want to fail in case there's some permission issue. */
+static int dummy_install_callback(sd_bus_message *message, void *userdata, sd_bus_error *ret_error) {
+        return 1;
+}
+
+int bus_register_malloc_status(sd_bus *bus, const char *destination) {
+        const char *match;
+        int r;
+
+        assert(bus);
+        assert(!isempty(destination));
+
+        match = strjoina("type='method_call',"
+                         "interface='org.freedesktop.MemoryAllocation1',"
+                         "path='/org/freedesktop/MemoryAllocation1',"
+                         "destination='", destination, "',",
+                         "member='GetMallocInfo'");
+
+        r = sd_bus_add_match_async(bus, NULL, match, method_dump_memory_state_by_fd, dummy_install_callback, NULL);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to subscribe to GetMallocInfo() calls on MemoryAllocation1 interface: %m");
+
+        return 0;
+}
+
 static void bus_message_unref_wrapper(void *m) {
         sd_bus_message_unref(m);
 }

src/shared/bus-util.h

@@ -63,4 +63,7 @@ static inline int bus_open_system_watch_bind(sd_bus **ret) {
 
 int bus_reply_pair_array(sd_bus_message *m, char **l);
 
+/* Listen to GetMallocInfo() calls to 'destination' and return malloc_info() via FD */
+int bus_register_malloc_status(sd_bus *bus, const char *destination);
+
 extern const struct hash_ops bus_message_hash_ops;

test/units/testsuite-65.sh

@@ -56,6 +56,7 @@ systemd-analyze dump "*" >/dev/null
 systemd-analyze dump "*.socket" >/dev/null
 systemd-analyze dump "*.socket" "*.service" aaaaaaa ... >/dev/null
 systemd-analyze dump systemd-journald.service >/dev/null
+systemd-analyze malloc >/dev/null
 (! systemd-analyze dump "")
 # unit-files
 systemd-analyze unit-files >/dev/null