Do not block SIGTERM in init's child processes
Previously, unless the process unblocks the signal by itself,
the signal was never delivered to the process. This caused at
least one CTS test failure.
Bug: 72453675
Test: 'kill -TERM app_pid' terminates the app process
Change-Id: I3977cac75e2673b52c5cf91d34d7a9c258c1a0e4
diff --git a/init/init.cpp b/init/init.cpp
index 79623c3..bd09e4b 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -19,6 +19,7 @@
#include <dirent.h>
#include <fcntl.h>
#include <paths.h>
+#include <pthread.h>
#include <seccomp_policy.h>
#include <signal.h>
#include <stdlib.h>
@@ -491,6 +492,16 @@
HandlePowerctlMessage("shutdown,container");
}
+static void UnblockSigterm() {
+ sigset_t mask;
+ sigemptyset(&mask);
+ sigaddset(&mask, SIGTERM);
+
+ if (sigprocmask(SIG_UNBLOCK, &mask, nullptr) == -1) {
+ PLOG(FATAL) << "failed to unblock SIGTERM for PID " << getpid();
+ }
+}
+
static void InstallSigtermHandler() {
sigset_t mask;
sigemptyset(&mask);
@@ -500,6 +511,12 @@
PLOG(FATAL) << "failed to block SIGTERM";
}
+ // Register a handler to unblock SIGTERM in the child processes.
+ const int result = pthread_atfork(nullptr, nullptr, &UnblockSigterm);
+ if (result != 0) {
+ LOG(FATAL) << "Failed to register a fork handler: " << strerror(result);
+ }
+
sigterm_signal_fd = signalfd(-1, &mask, SFD_CLOEXEC);
if (sigterm_signal_fd == -1) {
PLOG(FATAL) << "failed to create signalfd for SIGTERM";