Split the code to fill an exec closure into two functions.

This lets us initialize the exec closure early and fill in the
events later.  It also makes things consistent with the exec_pty
version.

src/exec_monitor.c

@@ -407,22 +407,34 @@ exec_cmnd_pty(struct command_details *details, sigset_t *mask,
 }
 
 /*
- * Fill in the monitor closure and setup initial events.
+ * Fill in the non-event part of the monitor closure.
- * Allocates read events for the signal pipe, error pipe and backchannel.
  */
 static void
-fill_exec_closure_monitor(struct monitor_closure *mc,
+init_exec_closure_monitor(struct monitor_closure *mc,
     const struct command_details *details, struct command_status *cstat,
-    int errfd, int backchannel)
+    int backchannel)
 {
-    debug_decl(fill_exec_closure_monitor, SUDO_DEBUG_EXEC);
+    debug_decl(init_exec_closure_monitor, SUDO_DEBUG_EXEC);
     
     /* Fill in the non-event part of the closure. */
+    memset(mc, 0, sizeof(*mc));
     mc->details = details;
     mc->cstat = cstat;
     mc->backchannel = backchannel;
     mc->mon_pgrp = getpgrp();
 
+    debug_return;
+}
+
+/*
+ * Fill in the monitor closure and setup initial events.
+ * Allocates read events for the signal pipe, error pipe and backchannel.
+ */
+static void
+init_exec_events_monitor(struct monitor_closure *mc, int errfd)
+{
+    debug_decl(init_exec_events_monitor, SUDO_DEBUG_EXEC);
+
     /* Setup event base and events. */
     mc->evbase = sudo_ev_base_alloc();
     if (mc->evbase == NULL)
@@ -437,7 +449,7 @@ fill_exec_closure_monitor(struct monitor_closure *mc,
 	sudo_fatal("%s", U_("unable to add event to queue"));
 
     /* Event for forwarded signals via backchannel. */
-    mc->backchannel_event = sudo_ev_alloc(backchannel,
+    mc->backchannel_event = sudo_ev_alloc(mc->backchannel,
 	SUDO_EV_READ|SUDO_EV_PERSIST, mon_backchannel_cb, mc);
     if (mc->backchannel_event == NULL)
 	sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
@@ -542,7 +554,7 @@ int
 exec_monitor(struct command_details *details, sigset_t *oset,
     bool foreground, int backchannel, int intercept_fd)
 {
-    struct monitor_closure mc = { 0 };
+    struct monitor_closure mc;
     struct command_status cstat;
     struct sigaction sa;
     int errsock[2];
@@ -578,6 +590,9 @@ exec_monitor(struct command_details *details, sigset_t *oset,
 	goto bad;
     }
 
+    /* Fill in exec closure after creating a new session. */
+    init_exec_closure_monitor(&mc, details, &cstat, backchannel);
+
     /*
      * The child waits on the other end of a socketpair for the
      * parent to set the controlling terminal.  It also writes
@@ -648,7 +663,7 @@ exec_monitor(struct command_details *details, sigset_t *oset,
      * Create new event base and register read events for the
      * signal pipe, error pipe, and backchannel.
      */
-    fill_exec_closure_monitor(&mc, details, &cstat, errsock[0], backchannel);
+    init_exec_events_monitor(&mc, errsock[0]);
 
     /* Restore signal mask now that signal handlers are setup. */
     sigprocmask(SIG_SETMASK, oset, NULL);

src/exec_nopty.c

@@ -201,19 +201,17 @@ signal_cb_nopty(int signo, int what, void *v)
     debug_return;
 }
 
-
 /*
- * Fill in the exec closure and setup initial exec events.
+ * Fill in the non-event part of the exec closure.
- * Allocates events for the signal pipe and error pipe.
  */
 static void
-fill_exec_closure(struct exec_closure *ec, struct command_status *cstat,
+init_exec_closure(struct exec_closure *ec, struct command_status *cstat,
-    struct command_details *details, const struct user_details *user_details,
+    struct command_details *details, const struct user_details *user_details)
-    struct sudo_event_base *evbase, int errfd)
 {
-    debug_decl(fill_exec_closure, SUDO_DEBUG_EXEC);
+    debug_decl(init_exec_closure, SUDO_DEBUG_EXEC);
 
     /* Fill in the non-event part of the closure. */
+    memset(ec, 0, sizeof(*ec));
     ec->sudo_pid = getpid();
     ec->ppgrp = getpgrp();
     ec->cstat = cstat;
@@ -221,6 +219,18 @@ fill_exec_closure(struct exec_closure *ec, struct command_status *cstat,
     ec->rows = user_details->ts_rows;
     ec->cols = user_details->ts_cols;
 
+    debug_return;
+}
+
+/*
+ * Allocate and set events for the signal pipe and error pipe.
+ */
+static void
+init_exec_events(struct exec_closure *ec, struct sudo_event_base *evbase,
+    int errfd)
+{
+    debug_decl(init_exec_events, SUDO_DEBUG_EXEC);
+
     /* Setup event base and events. */
     ec->evbase = evbase;
 
@@ -543,7 +553,7 @@ exec_nopty(struct command_details *details,
 {
     int io_pipe[3][2] = { { -1, -1 }, { -1, -1 }, { -1, -1 } };
     int errpipe[2], intercept_sv[2] = { -1, -1 };
-    struct exec_closure ec = { 0 };
+    struct exec_closure ec;
     sigset_t set, oset;
     debug_decl(exec_nopty, SUDO_DEBUG_EXEC);
 
@@ -554,6 +564,9 @@ exec_nopty(struct command_details *details,
     if (policy_init_session(details) != true)
 	sudo_fatalx("%s", U_("policy plugin failed session initialization"));
 
+    /* Fill in exec closure. */
+    init_exec_closure(&ec, cstat, details, user_details);
+
     /*
      * We use a pipe to get errno if execve(2) fails in the child.
      */
@@ -659,11 +672,8 @@ exec_nopty(struct command_details *details,
     if (ISSET(details->flags, CD_SET_TIMEOUT))
 	alarm(details->timeout);
 
-    /*
+    /* Allocate and set signal events and the error pipe event.  */
-     * Fill in exec closure, allocate event base, signal events and
+    init_exec_events(&ec, evbase, errpipe[0]);
-     * the error pipe event.
-     */
-    fill_exec_closure(&ec, cstat, details, user_details, evbase, errpipe[0]);
 
     if (ISSET(details->flags, CD_INTERCEPT|CD_LOG_SUBCMDS)) {
 	int rc = 1;

src/exec_pty.c

@@ -971,6 +971,7 @@ init_exec_closure(struct exec_closure *ec, struct command_status *cstat,
     debug_decl(init_exec_closure, SUDO_DEBUG_EXEC);
 
     /* Fill in the non-event part of the closure. */
+    memset(ec, 0, sizeof(*ec));
     ec->sudo_pid = sudo_pid;
     ec->ppgrp = ppgrp;
     ec->cmnd_pid = -1;