Make all signal handler functions async-signal-safe

by deleting the redundant "killersig" struct member
and using the existing sig_atomic_t cl_sigterm variable instead.
While here, garbage collect the h_hup() signal handler
which is essentially identical to h_term().
This also gets rid of the last #define & #undef in cl_main.c.

OK martijn@, and also tested by Tim <trondd at kagu hyphen tsuchi dot com>.

4 files changed, 17 insertions, 34 deletions

diff --git a/usr.bin/vi/cl/cl.h b/usr.bin/vi/cl/cl.h
index bfef0dc225a..8613313a0a5 100644
--- a/usr.bin/vi/cl/cl.h
+++ b/usr.bin/vi/cl/cl.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cl.h,v 1.11 2021/09/01 14:28:15 schwarze Exp $	*/
+/*	$OpenBSD: cl.h,v 1.12 2021/09/02 11:19:02 schwarze Exp $	*/
 
 /*-
  * Copyright (c) 1993, 1994
@@ -11,7 +11,6 @@
  *	@(#)cl.h	10.19 (Berkeley) 9/24/96
  */
 
-extern	volatile sig_atomic_t cl_sighup;
 extern	volatile sig_atomic_t cl_sigint;
 extern	volatile sig_atomic_t cl_sigterm;
 extern	volatile sig_atomic_t cl_sigwinch;
@@ -31,7 +30,6 @@ typedef struct _cl_private {
 	char	*rmso, *smso;	/* Inverse video terminal strings. */
 	char	*smcup, *rmcup;	/* Terminal start/stop strings. */
 
-	int	 killersig;	/* Killer signal. */
 #define	INDX_HUP	0
 #define	INDX_INT	1
 #define	INDX_TERM	2
diff --git a/usr.bin/vi/cl/cl_funcs.c b/usr.bin/vi/cl/cl_funcs.c
index eeb6046358f..24b18c675bf 100644
--- a/usr.bin/vi/cl/cl_funcs.c
+++ b/usr.bin/vi/cl/cl_funcs.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cl_funcs.c,v 1.21 2021/09/01 14:28:15 schwarze Exp $	*/
+/*	$OpenBSD: cl_funcs.c,v 1.22 2021/09/02 11:19:02 schwarze Exp $	*/
 
 /*-
  * Copyright (c) 1993, 1994
@@ -437,7 +437,7 @@ cl_refresh(SCR *sp, int repaint)
 	 * If we received a killer signal, we're done, there's no point
 	 * in refreshing the screen.
 	 */
-	if (clp->killersig)
+	if (cl_sigterm)
 		return (0);
 
 	/*
@@ -582,7 +582,7 @@ cl_suspend(SCR *sp, int *allowedp)
 	 * unchanged.  In addition, the terminal has already been reset
 	 * correctly, so leave it alone.
 	 */
-	if (clp->killersig) {
+	if (cl_sigterm) {
 		F_CLR(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT);
 		return (0);
 	}
diff --git a/usr.bin/vi/cl/cl_main.c b/usr.bin/vi/cl/cl_main.c
index 4cd624e72bf..5c38139c76d 100644
--- a/usr.bin/vi/cl/cl_main.c
+++ b/usr.bin/vi/cl/cl_main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cl_main.c,v 1.34 2021/09/01 14:28:15 schwarze Exp $	*/
+/*	$OpenBSD: cl_main.c,v 1.35 2021/09/02 11:19:02 schwarze Exp $	*/
 
 /*-
  * Copyright (c) 1993, 1994
@@ -33,7 +33,6 @@
 
 GS *__global_list;				/* GLOBAL: List of screens. */
 
-volatile sig_atomic_t cl_sighup;
 volatile sig_atomic_t cl_sigint;
 volatile sig_atomic_t cl_sigterm;
 volatile sig_atomic_t cl_sigwinch;
@@ -120,9 +119,9 @@ main(int argc, char *argv[])
 	}
 
 	/* If a killer signal arrived, pretend we just got it. */
-	if (clp->killersig) {
-		(void)signal(clp->killersig, SIG_DFL);
-		(void)kill(getpid(), clp->killersig);
+	if (cl_sigterm) {
+		(void)signal(cl_sigterm, SIG_DFL);
+		(void)kill(getpid(), cl_sigterm);
 		/* NOTREACHED */
 	}
 
@@ -215,17 +214,6 @@ term_init(char *ttype)
 	}
 }
 
-#define	GLOBAL_CLP \
-	CL_PRIVATE *clp = GCLP(__global_list);
-static void
-h_hup(int signo)
-{
-	GLOBAL_CLP;
-
-	cl_sighup = 1;
-	clp->killersig = SIGHUP;
-}
-
 static void
 h_int(int signo)
 {
@@ -235,10 +223,7 @@ h_int(int signo)
 static void
 h_term(int signo)
 {
-	GLOBAL_CLP;
-
-	cl_sigterm = 1;
-	clp->killersig = SIGTERM;
+	cl_sigterm = signo;
 }
 
 static void
@@ -246,7 +231,6 @@ h_winch(int signo)
 {
 	cl_sigwinch = 1;
 }
-#undef	GLOBAL_CLP
 
 /*
  * sig_init --
@@ -261,20 +245,19 @@ sig_init(GS *gp, SCR *sp)
 
 	clp = GCLP(gp);
 
-	cl_sighup = 0;
 	cl_sigint = 0;
 	cl_sigterm = 0;
 	cl_sigwinch = 0;
 
 	if (sp == NULL) {
-		if (setsig(SIGHUP, &clp->oact[INDX_HUP], h_hup) ||
+		if (setsig(SIGHUP, &clp->oact[INDX_HUP], h_term) ||
 		    setsig(SIGINT, &clp->oact[INDX_INT], h_int) ||
 		    setsig(SIGTERM, &clp->oact[INDX_TERM], h_term) ||
 		    setsig(SIGWINCH, &clp->oact[INDX_WINCH], h_winch)
 		    )
 			err(1, NULL);
 	} else
-		if (setsig(SIGHUP, NULL, h_hup) ||
+		if (setsig(SIGHUP, NULL, h_term) ||
 		    setsig(SIGINT, NULL, h_int) ||
 		    setsig(SIGTERM, NULL, h_term) ||
 		    setsig(SIGWINCH, NULL, h_winch)
diff --git a/usr.bin/vi/cl/cl_read.c b/usr.bin/vi/cl/cl_read.c
index aa3e1ba0dd4..0e4166aa146 100644
--- a/usr.bin/vi/cl/cl_read.c
+++ b/usr.bin/vi/cl/cl_read.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cl_read.c,v 1.22 2021/09/01 14:28:15 schwarze Exp $	*/
+/*	$OpenBSD: cl_read.c,v 1.23 2021/09/02 11:19:02 schwarze Exp $	*/
 
 /*-
  * Copyright (c) 1993, 1994
@@ -62,13 +62,15 @@ retest:	if (LF_ISSET(EC_INTERRUPT) || cl_sigint) {
 			evp->e_event = E_TIMEOUT;
 		return (0);
 	}
-	if (cl_sighup) {
+	switch (cl_sigterm) {
+	case SIGHUP:
 		evp->e_event = E_SIGHUP;
 		return (0);
-	}
-	if (cl_sigterm) {
+	case SIGTERM:
 		evp->e_event = E_SIGTERM;
 		return (0);
+	default:
+		break;
 	}
 	if (cl_sigwinch) {
 		cl_sigwinch = 0;