Bug#923924: Please review and apply attached patch to support shutdown on SIGPWR

[Andras Korn]

Package: runit
Version: 2.1.2-22
Severity: wishlist
Tags: upstream

Hi,

currently lxc can't cleanly shutdown a container running runit as its init
system, because all it can do to bring about a shutdown is send signals to
init (sigpwr by default), and runit requires additional steps to initiate a
shutdown.

I wrote a trivial patch that should add sigpwr support to runit. Please
review it and if you think it's OK, apply it and perhaps submit it to Gerrit
for inclusion.

Thanks!

András

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diff --git a/runit-2.1.2/man/runit.8 b/runit-2.1.2/man/runit.8
index 6c07cf8..d597fdd 100644
--- a/runit-2.1.2/man/runit.8
+++ b/runit-2.1.2/man/runit.8
@@ -75,6 +75,12 @@ exists and has the execute by owner permission set,
 .B runit
 is told to shutdown the system.
 .P
+If
+.B runit
+receives a PWR signal,
+.B runit
+is told to shutdown the system.
+.P
 if
 .B runit
 receives an INT signal, a ctrl-alt-del keyboard request is triggered.
diff --git a/runit-2.1.2/src/runit.c b/runit-2.1.2/src/runit.c
index 2bb4794..584207a 100644
--- a/runit-2.1.2/src/runit.c
+++ b/runit-2.1.2/src/runit.c
@@ -30,6 +30,7 @@ const char * const stage[3] ={
 int selfpipe[2];
 int sigc =0;
 int sigi =0;
+int sigp =0;
 
 void sig_cont_handler (void) {
   sigc++;
@@ -39,6 +40,10 @@ void sig_int_handler (void) {
   sigi++;
   write(selfpipe[1], "", 1);
 }
+void sig_pwr_handler (void) {
+  sigp++;
+  write(selfpipe[1], "", 1);
+}
 void sig_child_handler (void) { write(selfpipe[1], "", 1); }
 
 void sync_if_needed() {
@@ -71,6 +76,7 @@ int main (int argc, const char * const *argv, char * const *envp) {
   sig_block(sig_hangup);
   sig_block(sig_int);
   sig_catch(sig_int, sig_int_handler);
+  sig_catch(sig_pwr, sig_pwr_handler);
   sig_block(sig_pipe);
   sig_block(sig_term);
 
@@ -244,7 +250,7 @@ int main (int argc, const char * const *argv, char * const *envp) {
         sigi =0;
         sigc++;
       }
-      if (sigc && (stat(STOPIT, &s) != -1) && (s.st_mode & S_IXUSR)) {
+      if ((sigp) || (sigc && (stat(STOPIT, &s) != -1) && (s.st_mode & S_IXUSR))) {
         int i;
         /* unlink(STOPIT); */
         chmod(STOPIT, 0);
@@ -308,7 +314,7 @@ int main (int argc, const char * const *argv, char * const *envp) {
   switch (pid) {
   case  0:
   case -1:
-  if ((stat(REBOOT, &s) != -1) && (s.st_mode & S_IXUSR)) {
+  if ((!sigp) && ((stat(REBOOT, &s) != -1) && (s.st_mode & S_IXUSR))) {
     strerr_warn2(INFO, "system reboot.", 0);
     sync_if_needed();
     reboot_system(RB_AUTOBOOT);
diff --git a/runit-2.1.2/src/sig.c b/runit-2.1.2/src/sig.c
index 423d18e..9d9d69b 100644
--- a/runit-2.1.2/src/sig.c
+++ b/runit-2.1.2/src/sig.c
@@ -9,6 +9,7 @@ int sig_cont = SIGCONT;
 int sig_hangup = SIGHUP;
 int sig_int = SIGINT;
 int sig_pipe = SIGPIPE;
+int sig_pwr = SIGPWR;
 int sig_term = SIGTERM;
 
 void (*sig_defaulthandler)() = SIG_DFL;
diff --git a/runit-2.1.2/src/sig.h b/runit-2.1.2/src/sig.h
index 2a3c780..0ced62d 100644
--- a/runit-2.1.2/src/sig.h
+++ b/runit-2.1.2/src/sig.h
@@ -9,6 +9,7 @@ extern int sig_cont;
 extern int sig_hangup;
 extern int sig_int;
 extern int sig_pipe;
+extern int sig_pwr;
 extern int sig_term;
 
 extern void (*sig_defaulthandler)();