Hello Tony,

On 10/9/24 01:12, Tony Ambardar wrote:

Existing code calls connect() with a 'struct sockaddr_in6 *' argument where a 'struct sockaddr *' argument is declared, yielding compile errors when building for mips64el/musl-libc:

In file included from cgroup_ancestor.c:3: cgroup_ancestor.c: In function 'send_datagram': cgroup_ancestor.c:38:38: error: passing argument 2 of 'connect' from incompatible pointer type [-Werror=incompatible-pointer-types] 38 | if (!ASSERT_OK(connect(sock, &addr, sizeof(addr)), "connect")) { | ^~~~~ | | | struct sockaddr_in6 * ./test_progs.h:343:29: note: in definition of macro 'ASSERT_OK' 343 | long long ___res = (res); \ | ^~~ In file included from .../netinet/in.h:10, from .../arpa/inet.h:9, from ./test_progs.h:17: .../sys/socket.h:386:19: note: expected 'const struct sockaddr *' but argument is of type 'struct sockaddr_in6 *' 386 | int connect (int, const struct sockaddr *, socklen_t); | ^~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors

This only compiles because of a glibc extension allowing declaration of the argument as a "transparent union" which includes both types above.

Explicitly cast the argument to allow compiling for both musl and glibc.

Thanks for the fix and the details :) Indeed it looks like all other tests perform this cast on connect (either to (void *) or (struct sockaddr *)) to prevent this issue, so that's a miss on my side when I rewrote this test.

Cc: Alexis Lothoré (eBPF Foundation) alexis.lothore@bootlin.com Fixes: f957c230e173 ("selftests/bpf: convert test_skb_cgroup_id_user to test_progs") Signed-off-by: Tony Ambardar tony.ambardar@gmail.com

Reviewed-by: Alexis Lothoré alexis.lothore@bootlin.com

---

tools/testing/selftests/bpf/prog_tests/cgroup_ancestor.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_ancestor.c b/tools/testing/selftests/bpf/prog_tests/cgroup_ancestor.c index 9250a1e9f9af..3f9ffdf71343 100644 --- a/tools/testing/selftests/bpf/prog_tests/cgroup_ancestor.c +++ b/tools/testing/selftests/bpf/prog_tests/cgroup_ancestor.c @@ -35,7 +35,7 @@ static int send_datagram(void) if (!ASSERT_OK_FD(sock, "create socket")) return sock;

• if (!ASSERT_OK(connect(sock, &addr, sizeof(addr)), "connect")) {

• if (!ASSERT_OK(connect(sock, (struct sockaddr *)&addr, sizeof(addr)), "connect")) { close(sock); return -1; }