From 9afce0b45c396e43a5499f227cc21849812a435b Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Wed, 30 Oct 2024 21:36:18 +0100 Subject: [PATCH] tap: Explicitly cast TUNSETIFF to fix build warning with musl on ppc64le On ppc64le, TUNSETIFF happens to be 2147767498, which is bigger than INT_MAX (2^31 - 1), and musl declares the second argument of ioctl() as 'int', not 'unsigned long' like glibc does, probably because of how POSIX specifies the equivalent argument, int dcmd, in posix_devctl(), so gcc reports a warning: tap.c: In function 'tap_ns_tun': tap.c:1291:24: warning: overflow in conversion from 'long unsigned int' to 'int' changes value from '2147767498' to '-2147199798' [-Woverflow] 1291 | rc = ioctl(fd, TUNSETIFF, &ifr); | ^~~~~~~~~ We don't care about that overflow, so explicitly cast TUNSETIFF to int. Signed-off-by: Stefano Brivio Reviewed-by: David Gibson --- tap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tap.c b/tap.c index cfb82e9..f638f2c 100644 --- a/tap.c +++ b/tap.c @@ -1288,7 +1288,7 @@ static int tap_ns_tun(void *arg) if (fd < 0) die_perror("Failed to open() /dev/net/tun"); - rc = ioctl(fd, TUNSETIFF, &ifr); + rc = ioctl(fd, (int)TUNSETIFF, &ifr); if (rc < 0) die_perror("TUNSETIFF ioctl on /dev/net/tun failed");