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authorIngo Schwarze <schwarze@openbsd.org>2015-11-14 23:57:47 +0000
committerIngo Schwarze <schwarze@openbsd.org>2015-11-14 23:57:47 +0000
commit15be0ab8c964a27a1e5cfa3fdf7a8d5c5a94718b (patch)
treedc1c111a7a56c4e724754f6478fca23ce241eb40 /main.c
parentd3b0efc7635aefb8712b44baed58a7a281b97b40 (diff)
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Fix an issue reported by deraadt@: When hitting Ctrl-Backslash (= SIGQUIT)
in the less(1) spawned by man(1), man(1) died uncleanly, leaving behind its temp files, and killed less(1) uncleanly as well with SIGPIPE, leaving the terminal in the wrong state. Fix this by giving less(1) its own process group and handing it control of the terminal, but in such a way that Ctrl-z (= SIGSTOP) still works: In that case, let man(1) stop itself, too, and let it continue the pager when it continues itself. Joint work with millert@ who contributed most of the expertise required, and also most parts of the code. OK deraadt@ millert@
Diffstat (limited to 'main.c')
-rw-r--r--main.c40
1 files changed, 35 insertions, 5 deletions
diff --git a/main.c b/main.c
index d2d7e087..ecdf4eb2 100644
--- a/main.c
+++ b/main.c
@@ -1,4 +1,4 @@
-/* $Id: main.c,v 1.257 2015/11/07 17:58:55 schwarze Exp $ */
+/* $Id: main.c,v 1.258 2015/11/14 23:57:47 schwarze Exp $ */
/*
* Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
* Copyright (c) 2010-2012, 2014, 2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -27,6 +27,7 @@
#if HAVE_ERR
#include <err.h>
#endif
+#include <errno.h>
#include <fcntl.h>
#include <glob.h>
#include <signal.h>
@@ -131,7 +132,9 @@ main(int argc, char *argv[])
int show_usage;
int options;
int use_pager;
+ int status;
int c;
+ pid_t pager_pid;
#if HAVE_PROGNAME
progname = getprogname();
@@ -152,7 +155,7 @@ main(int argc, char *argv[])
#endif
#if HAVE_PLEDGE
- if (pledge("stdio rpath tmppath proc exec flock", NULL) == -1)
+ if (pledge("stdio rpath tmppath tty proc exec flock", NULL) == -1)
err((int)MANDOCLEVEL_SYSERR, "pledge");
#endif
@@ -427,7 +430,7 @@ main(int argc, char *argv[])
/* mandoc(1) */
#if HAVE_PLEDGE
- if (pledge(use_pager ? "stdio rpath tmppath proc exec" :
+ if (pledge(use_pager ? "stdio rpath tmppath tty proc exec" :
"stdio rpath", NULL) == -1)
err((int)MANDOCLEVEL_SYSERR, "pledge");
#endif
@@ -527,7 +530,29 @@ out:
if (tag_files != NULL) {
fclose(stdout);
tag_write();
- waitpid(spawn_pager(tag_files), NULL, 0);
+ pager_pid = spawn_pager(tag_files);
+ for (;;) {
+ if (waitpid(pager_pid, &status, WUNTRACED) == -1) {
+ if (errno == EINTR)
+ continue;
+ warn("wait");
+ rc = MANDOCLEVEL_SYSERR;
+ break;
+ }
+ if (!WIFSTOPPED(status))
+ break;
+
+ (void)tcsetpgrp(STDIN_FILENO, getpgid(0));
+ kill(0, WSTOPSIG(status));
+
+ /*
+ * I'm now stopped.
+ * When getting SIGCONT, continue here:
+ */
+
+ (void)tcsetpgrp(STDIN_FILENO, pager_pid);
+ kill(pager_pid, SIGCONT);
+ }
tag_unlink();
}
@@ -1016,10 +1041,15 @@ spawn_pager(struct tag_files *tag_files)
case -1:
err((int)MANDOCLEVEL_SYSERR, "fork");
case 0:
+ /* Set pgrp in both parent and child to avoid racing exec. */
+ (void)setpgid(0, 0);
break;
default:
+ (void)setpgid(pager_pid, 0);
+ if (tcsetpgrp(STDIN_FILENO, pager_pid) == -1)
+ err((int)MANDOCLEVEL_SYSERR, "tcsetpgrp");
#if HAVE_PLEDGE
- if (pledge("stdio rpath tmppath", NULL) == -1)
+ if (pledge("stdio rpath tmppath tty proc", NULL) == -1)
err((int)MANDOCLEVEL_SYSERR, "pledge");
#endif
return pager_pid;