[PATCH 05/13] examples/vdpa: make signal handler safe

[Stephen Hemminger <stephen@networkplumber.org>]

The handler called printf(), the vhost library teardown path and
exit(), none of which are async-signal-safe.

Set a flag and do the teardown in main() once the input loop returns.
This also closes the vDPA devices on exit from interactive mode, which
was missing before.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 examples/vdpa/main.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/examples/vdpa/main.c b/examples/vdpa/main.c
index ac6da79b05..1b989fc6e5 100644
--- a/examples/vdpa/main.c
+++ b/examples/vdpa/main.c
@@ -288,14 +288,13 @@ vdpa_sample_quit(void)
 	}
 }
 
+/* Set by SIGINT and SIGTERM handler, consumed by main(). */
+static volatile sig_atomic_t quit;
+
 static void
-signal_handler(int signum)
+signal_handler(__rte_unused int signum)
 {
-	if (signum == SIGINT || signum == SIGTERM) {
-		printf("\nSignal %d received, preparing to exit...\n", signum);
-		vdpa_sample_quit();
-		exit(0);
-	}
+	quit = 1;
 }
 
 /* interactive cmd functions */
@@ -513,7 +512,7 @@ main(int argc, char *argv[])
 		}
 
 		printf("enter \'q\' to quit\n");
-		while (scanf("%c", &ch)) {
+		while (!quit && scanf("%c", &ch)) {
 			if (ch == 'q')
 				break;
 			while (ch != '\n') {
@@ -522,9 +521,10 @@ main(int argc, char *argv[])
 			}
 			printf("enter \'q\' to quit\n");
 		}
-		vdpa_sample_quit();
 	}
 
+	vdpa_sample_quit();
+
 	/* clean up the EAL */
 	rte_eal_cleanup();
 
-- 
2.53.0