Module Name: src
Committed By: christos
Date: Fri Feb 11 21:15:25 UTC 2022
Modified Files:
src/usr.bin/script: script.c
Log Message:
PR/56254: RVP: Don't call non-async-signal-safe functions from signal handlers.
Establish a non-restart signal handler to avoid blocking in long I/Os.
To generate a diff of this commit:
cvs rdiff -u -r1.30 -r1.31 src/usr.bin/script/script.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.bin/script/script.c
diff -u src/usr.bin/script/script.c:1.30 src/usr.bin/script/script.c:1.31
--- src/usr.bin/script/script.c:1.30 Thu Jan 20 14:49:51 2022
+++ src/usr.bin/script/script.c Fri Feb 11 16:15:25 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: script.c,v 1.30 2022/01/20 19:49:51 christos Exp $ */
+/* $NetBSD: script.c,v 1.31 2022/02/11 21:15:25 christos Exp $ */
/*
* Copyright (c) 1980, 1992, 1993
@@ -39,7 +39,7 @@ __COPYRIGHT("@(#) Copyright (c) 1980, 19
#if 0
static char sccsid[] = "@(#)script.c 8.1 (Berkeley) 6/6/93";
#endif
-__RCSID("$NetBSD: script.c,v 1.30 2022/01/20 19:49:51 christos Exp $");
+__RCSID("$NetBSD: script.c,v 1.31 2022/02/11 21:15:25 christos Exp $");
#endif /* not lint */
#include <sys/types.h>
@@ -81,6 +81,8 @@ static int usesleep, rawout;
static int quiet, flush;
static const char *fname;
+static volatile sig_atomic_t die = 0; /* exit if 1 */
+static int cstat = EXIT_SUCCESS; /* cmd. exit status */
static int eflag;
static int isterm;
static struct termios tt;
@@ -88,6 +90,7 @@ static struct termios tt;
__dead static void done(int);
__dead static void doshell(const char *);
__dead static void fail(void);
+static sig_t xsignal(int, sig_t);
static void dooutput(void);
static void finish(int);
static void scriptflush(int);
@@ -182,7 +185,7 @@ main(int argc, char *argv[])
(void)tcsetattr(STDIN_FILENO, TCSAFLUSH, &rtt);
}
- (void)signal(SIGCHLD, finish);
+ (void)xsignal(SIGCHLD, finish);
child = fork();
if (child == -1) {
warn("fork");
@@ -202,35 +205,49 @@ main(int argc, char *argv[])
if (!rawout)
(void)fclose(fscript);
- while ((scc = read(STDIN_FILENO, ibuf, BUFSIZ)) > 0) {
+ while (!die && (scc = read(STDIN_FILENO, ibuf, BUFSIZ)) > 0) {
cc = (size_t)scc;
if (rawout)
record(fscript, ibuf, cc, 'i');
(void)write(master, ibuf, cc);
}
- finish(-1);
+ done(cstat);
+}
+
+/**
+ * wrapper around sigaction() because we want POSIX semantics:
+ * no auto-restarting of interrupted slow syscalls.
+ */
+static sig_t
+xsignal(int signo, sig_t handler)
+{
+ struct sigaction sa, osa;
+
+ sa.sa_handler = handler;
+ sa.sa_flags = 0;
+ sigemptyset(&sa.sa_mask);
+ if (sigaction(signo, &sa, &osa) == -1)
+ return SIG_ERR;
+ return osa.sa_handler;
}
static void
finish(int signo)
{
- int die, pid, status, cstat;
+ int pid, status;
- die = 0;
while ((pid = wait(&status)) > 0)
if (pid == child) {
cstat = status;
die = 1;
}
- if (!die)
- return;
if (!eflag)
- done(EXIT_SUCCESS);
+ cstat = EXIT_SUCCESS;
else if (WIFEXITED(cstat))
- done(WEXITSTATUS(cstat));
+ cstat = WEXITSTATUS(cstat);
else
- done(128 + WTERMSIG(cstat));
+ cstat = 128 + WTERMSIG(cstat);
}
static void
@@ -268,7 +285,7 @@ dooutput(void)
if (flush)
(void)fflush(fscript);
}
- finish(-1);
+ done(cstat);
}
static void
