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author | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2019-05-08 14:39:57 +0200 |
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committer | Lukas Nykryn <lnykryn@redhat.com> | 2020-02-03 11:05:28 +0100 |
commit | 8e155b3dad29a96cd2586185c63604c42bc5690e (patch) | |
tree | 3102be2e36323f73a83135aa9af21c497e760509 | |
parent | f16b5124274f35c475cb70fa936567877a4b74f9 (diff) | |
download | systemd-8e155b3dad29a96cd2586185c63604c42bc5690e.tar.gz |
sd-event: add sd_event_source_disable_unref() helper
(cherry picked from commit afd15bbb4b6414b9356799c63029e36642dae8e4)
Related: CVE-2020-1712
-rw-r--r-- | man/rules/meson.build | 4 | ||||
-rw-r--r-- | man/sd_event_source_unref.xml | 30 | ||||
-rw-r--r-- | src/libsystemd/libsystemd.sym | 1 | ||||
-rw-r--r-- | src/libsystemd/sd-event/sd-event.c | 6 | ||||
-rw-r--r-- | src/systemd/sd-event.h | 1 |
5 files changed, 30 insertions, 12 deletions
diff --git a/man/rules/meson.build b/man/rules/meson.build index 989d11c9b9..7ae94ea265 100644 --- a/man/rules/meson.build +++ b/man/rules/meson.build @@ -340,7 +340,9 @@ manpages = [ ['sd_event_source_set_userdata', '3', ['sd_event_source_get_userdata'], ''], ['sd_event_source_unref', '3', - ['sd_event_source_ref', 'sd_event_source_unrefp'], + ['sd_event_source_disable_unref', + 'sd_event_source_ref', + 'sd_event_source_unrefp'], ''], ['sd_event_wait', '3', diff --git a/man/sd_event_source_unref.xml b/man/sd_event_source_unref.xml index d1b83c57aa..af8fed33f2 100644 --- a/man/sd_event_source_unref.xml +++ b/man/sd_event_source_unref.xml @@ -22,6 +22,7 @@ <refname>sd_event_source_unref</refname> <refname>sd_event_source_unrefp</refname> <refname>sd_event_source_ref</refname> + <refname>sd_event_source_disable_unref</refname> <refpurpose>Increase or decrease event source reference counters</refpurpose> </refnamediv> @@ -45,6 +46,10 @@ <paramdef>sd_event_source *<parameter>source</parameter></paramdef> </funcprototype> + <funcprototype> + <funcdef>sd_event_source* <function>sd_event_source_disable_unref</function></funcdef> + <paramdef>sd_event_source *<parameter>source</parameter></paramdef> + </funcprototype> </funcsynopsis> </refsynopsisdiv> @@ -80,23 +85,26 @@ the passed event source object is <constant>NULL</constant>.</para> - <para>Note that event source objects stay alive and may be - dispatched as long as they have a reference counter greater than - zero. In order to drop a reference of an event source and make - sure the associated event source handler function is not called - anymore it is recommended to combine a call of + <para>Note that event source objects stay alive and may be dispatched as long as they have a reference + counter greater than zero. In order to drop a reference of an event source and make sure the associated + event source handler function is not called anymore it is recommended to combine a call of <function>sd_event_source_unref()</function> with a prior call to - <function>sd_event_source_set_enabled()</function> with - <constant>SD_EVENT_OFF</constant>.</para> + <function>sd_event_source_set_enabled()</function> with <constant>SD_EVENT_OFF</constant> or call + <function>sd_event_source_disable_unref()</function>, see below.</para> + + <para><function>sd_event_source_disable_unref()</function> combines a call to + <function>sd_event_source_set_enabled()</function> with <constant>SD_EVENT_OFF</constant> with + <function>sd_event_source_unref()</function>. This ensures that the source is disabled before the local + reference to it is lost. The <parameter>source</parameter> parameter is allowed to be + <constant>NULL</constant>.</para> </refsect1> <refsect1> <title>Return Value</title> - <para><function>sd_event_source_unref()</function> always returns - <constant>NULL</constant>. - <function>sd_event_source_ref()</function> always returns the - event source object passed in.</para> + <para><function>sd_event_source_unref()</function> and + <function>sd_event_source_disable_unref()</function> always return <constant>NULL</constant>. + <function>sd_event_source_ref()</function> always returns the event source object passed in.</para> </refsect1> <xi:include href="libsystemd-pkgconfig.xml" /> diff --git a/src/libsystemd/libsystemd.sym b/src/libsystemd/libsystemd.sym index e9972593a6..778e88a16c 100644 --- a/src/libsystemd/libsystemd.sym +++ b/src/libsystemd/libsystemd.sym @@ -570,4 +570,5 @@ global: sd_event_source_set_destroy_callback; sd_event_source_get_destroy_callback; sd_bus_enqueue_for_read; + sd_event_source_disable_unref; } LIBSYSTEMD_238; diff --git a/src/libsystemd/sd-event/sd-event.c b/src/libsystemd/sd-event/sd-event.c index d53b9a7026..0d3bf5cbb6 100644 --- a/src/libsystemd/sd-event/sd-event.c +++ b/src/libsystemd/sd-event/sd-event.c @@ -580,6 +580,12 @@ _public_ sd_event* sd_event_unref(sd_event *e) { return NULL; } +_public_ sd_event_source* sd_event_source_disable_unref(sd_event_source *s) { + if (s) + (void) sd_event_source_set_enabled(s, SD_EVENT_OFF); + return sd_event_source_unref(s); +} + static bool event_pid_changed(sd_event *e) { assert(e); diff --git a/src/systemd/sd-event.h b/src/systemd/sd-event.h index 7fcae4ac49..9876be01c6 100644 --- a/src/systemd/sd-event.h +++ b/src/systemd/sd-event.h @@ -113,6 +113,7 @@ int sd_event_get_iteration(sd_event *e, uint64_t *ret); sd_event_source* sd_event_source_ref(sd_event_source *s); sd_event_source* sd_event_source_unref(sd_event_source *s); +sd_event_source* sd_event_source_disable_unref(sd_event_source *s); sd_event *sd_event_source_get_event(sd_event_source *s); void* sd_event_source_get_userdata(sd_event_source *s); |