From 99f2d650f37cd1206f083ce9a676a48c1546545f Mon Sep 17 00:00:00 2001
From: Ryan Wilson <ryantimwilson@meta.com>
Date: Oct 29 2024 18:07:59 +0000
Subject: core: Add debug logging for systemd killing services/units


---

diff --git a/0001-core-Add-debug-logging-for-systemd-killing-services-.patch b/0001-core-Add-debug-logging-for-systemd-killing-services-.patch
new file mode 100644
index 0000000..60b854a
--- /dev/null
+++ b/0001-core-Add-debug-logging-for-systemd-killing-services-.patch
@@ -0,0 +1,86 @@
+From a246b1c63f082565c4492d8bdd945623863df07d Mon Sep 17 00:00:00 2001
+From: Ryan Wilson <ryantimwilson@meta.com>
+Date: Tue, 29 Oct 2024 10:25:53 -0700
+Subject: [PATCH] core: Add debug logging for systemd killing services/units
+
+---
+ src/basic/pidref.c |  2 ++
+ src/core/service.c |  3 +++
+ src/core/unit.c    | 12 ++++++++++++
+ src/core/unit.h    |  3 +++
+ 4 files changed, 20 insertions(+)
+
+diff --git a/src/basic/pidref.c b/src/basic/pidref.c
+index 69a010210d..6bd7198d0d 100644
+--- a/src/basic/pidref.c
++++ b/src/basic/pidref.c
+@@ -268,6 +268,8 @@ int pidref_kill(const PidRef *pidref, int sig) {
+         if (!pidref)
+                 return -ESRCH;
+ 
++        log_debug("Sending signal %s for PID " PID_FMT " and PIDFD %d", signal_to_string(sig), pidref->pid, pidref->fd);
++
+         if (pidref->fd >= 0)
+                 return RET_NERRNO(pidfd_send_signal(pidref->fd, sig, NULL, 0));
+ 
+diff --git a/src/core/service.c b/src/core/service.c
+index 6e81460ad0..577f1f067d 100644
+--- a/src/core/service.c
++++ b/src/core/service.c
+@@ -2138,6 +2138,9 @@ static void service_enter_signal(Service *s, ServiceState state, ServiceResult f
+          * died now */
+         (void) unit_enqueue_rewatch_pids(UNIT(s));
+ 
++        log_unit_debug(UNIT(s), "Sending signal to unit for state %s with result %s",
++                       service_state_to_string(state), service_result_to_string(f));
++
+         kill_operation = state_to_kill_operation(s, state);
+         r = unit_kill_context(UNIT(s), kill_operation);
+         if (r < 0) {
+diff --git a/src/core/unit.c b/src/core/unit.c
+index 136b7aacb0..3a47331985 100644
+--- a/src/core/unit.c
++++ b/src/core/unit.c
+@@ -4796,6 +4796,16 @@ static int unit_kill_context_one(
+         return !is_alien;
+ }
+ 
++static const char* const kill_operation_table[_KILL_OPERATION_MAX] = {
++        [KILL_TERMINATE]         = "terminate",
++        [KILL_TERMINATE_AND_LOG] = "terminate-and-log",
++        [KILL_RESTART]           = "restart",
++        [KILL_KILL]              = "kill",
++        [KILL_WATCHDOG]          = "watchdog",
++};
++
++DEFINE_STRING_TABLE_LOOKUP(kill_operation, KillOperation);
++
+ int unit_kill_context(Unit *u, KillOperation k) {
+         bool wait_for_exit = false, send_sighup;
+         cg_kill_log_func_t log_func = NULL;
+@@ -4807,6 +4817,8 @@ int unit_kill_context(Unit *u, KillOperation k) {
+          * if we killed something worth waiting for, 0 otherwise. Do not confuse with unit_kill_common()
+          * which is used for user-requested killing of unit processes. */
+ 
++        log_unit_debug(u, "Killing unit context with operation %s", kill_operation_to_string(k));
++
+         KillContext *c = unit_get_kill_context(u);
+         if (!c || c->kill_mode == KILL_NONE)
+                 return 0;
+diff --git a/src/core/unit.h b/src/core/unit.h
+index b135fecc51..e46dfb7c58 100644
+--- a/src/core/unit.h
++++ b/src/core/unit.h
+@@ -1053,6 +1053,9 @@ UnitMountDependencyType unit_mount_dependency_type_from_string(const char *s) _c
+ const char* unit_mount_dependency_type_to_string(UnitMountDependencyType t) _const_;
+ UnitDependency unit_mount_dependency_type_to_dependency_type(UnitMountDependencyType t) _pure_;
+ 
++const char* kill_operation_to_string(KillOperation t) _const_;
++KillOperation kill_operation_from_string(const char *s) _pure_;
++
+ /* Macros which append UNIT= or USER_UNIT= to the message */
+ 
+ #define log_unit_full_errno_zerook(unit, level, error, ...)             \
+-- 
+2.43.5
+
diff --git a/systemd.spec b/systemd.spec
index bf7f84b..357b07b 100644
--- a/systemd.spec
+++ b/systemd.spec
@@ -44,7 +44,7 @@ Url:            https://systemd.io
 # Allow users to specify the version and release when building the rpm by 
 # setting the %%version_override and %%release_override macros.
 Version:        %{?version_override}%{!?version_override:256.7}
-Release:        %{?release_override}%{!?release_override:1.3}%{?dist}
+Release:        %{?release_override}%{!?release_override:1.4}%{?dist}
 
 %global stable %(c="%version"; [ "$c" = "${c#*.*}" ]; echo $?)
 
@@ -148,6 +148,11 @@ Patch0903: 0001-keep-on-using-DBus-as-fallback-if-varlink-is-not-ava.patch
 # bus-util: Return ENOMEDIUM if XDG_RUNTIME_DIR is unset
 Patch0904:      https://github.com/systemd/systemd/pull/34851.patch
 
+# core: Add debug logging for systemd killing services/units
+# Once we root cause systemd 256 killing services/units on upgrade, we should
+# upstream this patch + any other patches used for debugging.
+Patch0905:      0001-core-Add-debug-logging-for-systemd-killing-services-.patch
+
 %endif
 
 %ifarch %{ix86} x86_64 aarch64 riscv64