From: Tobias Stoeckmann <tobias@stoeckmann.org>
Date: Fri, 9 Jan 2026 20:05:02 +0000 (+0100)
Subject: fdisk: make SIGINT handler signal-safe
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=823885370873313038a43649d6fceada0dc07083;p=thirdparty%2Futil-linux.git

fdisk: make SIGINT handler signal-safe

Checking debug options and calling fprintf is not signal-safe.
Install a debug handler if debugging is requested and use signal-safe
output in it.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
---

diff --git a/disk-utils/fdisk.c b/disk-utils/fdisk.c
index f44a4899e..d46a468e8 100644
--- a/disk-utils/fdisk.c
+++ b/disk-utils/fdisk.c
@@ -81,7 +81,13 @@ static void fdiskprog_init_debug(void)
 
 static void reply_sighandler(int sig __attribute__((unused)))
 {
-	DBG(ASK, ul_debug("got signal"));
+	/* nothing to do here */
+}
+
+static void reply_debug_sighandler(int sig __attribute__((unused)))
+{
+	/* signal-safe version of DBG(ASK, ul_debug("got signal")) */
+	ul_sig_printf("%d: %s: %8s: %s\n", getpid(), "fdisk", "ASK", "got signal");
 }
 
 static int reply_running;
@@ -111,6 +117,7 @@ int get_user_reply(const char *prompt, char *buf, size_t bufsz)
 	DBG(ASK, ul_debug("asking for user reply %s", is_interactive ? "[interactive]" : ""));
 
 	sigemptyset(&act.sa_mask);
+	ON_DBG(ASK, act.sa_handler = reply_debug_sighandler);
 	sigaction(SIGINT, &act, &oldact);
 
 #ifdef HAVE_LIBREADLINE