Add xsignal_flags() and more consistently use xsignal() instead of signal().

xsignal() wraps sigaction() giving control of SA_RESTART behavior and such.

4 files changed, 13 insertions, 3 deletions

diff --git a/lib/lib.c b/lib/lib.c
index 17a4f483..9deadad9 100644
--- a/lib/lib.c
+++ b/lib/lib.c
@@ -854,7 +854,9 @@ void sigatexit(void *handler)
   int i;
 
   for (i=0; signames[i].num != SIGCHLD; i++)
-    signal(signames[i].num, handler ? exit_signal : SIG_DFL);
+    if (signames[i].num != SIGKILL)
+      xsignal(signames[i].num, handler ? exit_signal : SIG_DFL);
+
   if (handler) {
     al = xmalloc(sizeof(struct arg_list));
     al->next = toys.xexit;
diff --git a/lib/lib.h b/lib/lib.h
index 18eb0509..136cdab5 100644
--- a/lib/lib.h
+++ b/lib/lib.h
@@ -175,6 +175,7 @@ long xparsetime(char *arg, long units, long *fraction);
 void xpidfile(char *name);
 void xregcomp(regex_t *preg, char *rexec, int cflags);
 char *xtzset(char *new);
+void xsignal_flags(int signal, void *handler, int flags);
 void xsignal(int signal, void *handler);
 
 // lib.c
diff --git a/lib/password.c b/lib/password.c
index a02bc542..b9cc1346 100644
--- a/lib/password.c
+++ b/lib/password.c
@@ -53,7 +53,8 @@ int read_password(char *buf, int buflen, char *mesg)
   struct sigaction sa, oldsa;
   int i, ret = 1;
 
-  // NOP signal handler to return from the read
+  // NOP signal handler to return from the read. Use sigaction() instead
+  // of xsignal() because we want to restore the old handler afterwards.
   memset(&sa, 0, sizeof(sa));
   sa.sa_handler = generic_signal;
   sigaction(SIGINT, &sa, &oldsa);
diff --git a/lib/xwrap.c b/lib/xwrap.c
index 3e0f57e4..7276151f 100644
--- a/lib/xwrap.c
+++ b/lib/xwrap.c
@@ -841,12 +841,18 @@ char *xtzset(char *new)
 }
 
 // Set a signal handler
-void xsignal(int signal, void *handler)
+void xsignal_flags(int signal, void *handler, int flags)
 {
   struct sigaction *sa = (void *)libbuf;
 
   memset(sa, 0, sizeof(struct sigaction));
   sa->sa_handler = handler;
+  sa->sa_flags = flags;
 
   if (sigaction(signal, sa, 0)) perror_exit("xsignal %d", signal);
 }
+
+void xsignal(int signal, void *handler)
+{
+  xsignal_flags(signal, handler, 0);
+}