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.loth...@bootlin.com>
> Fixes: f957c230e173 ("selftests/bpf: convert test_skb_cgroup_id_user to
> test_progs")
> Signed-off-by: Tony Ambardar <tony.ambar...@gmail.com>
Reviewed-by: Alexis Lothoré <alexis.loth...@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;
> }
--
Alexis Lothoré, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
