This is a note to let you know that I've just added the patch titled
selftests/bpf: Fix error compiling tc_redirect.c with musl libc
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
selftests-bpf-fix-error-compiling-tc_redirect.c-with.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9807c794cc405857bd4c71538a229d2d8b8c3489
Author: Tony Ambardar <tony.ambardar@xxxxxxxxx>
Date: Mon Jul 29 02:24:24 2024 -0700
selftests/bpf: Fix error compiling tc_redirect.c with musl libc
[ Upstream commit 21c5f4f55da759c7444a1ef13e90b6e6f674eeeb ]
Linux 5.1 implemented 64-bit time types and related syscalls to address the
Y2038 problem generally across archs. Userspace handling of Y2038 varies
with the libc however. While musl libc uses 64-bit time across all 32-bit
and 64-bit platforms, GNU glibc uses 64-bit time on 64-bit platforms but
defaults to 32-bit time on 32-bit platforms unless they "opt-in" to 64-bit
time or explicitly use 64-bit syscalls and time structures.
One specific area is the standard setsockopt() call, SO_TIMESTAMPNS option
used for timestamping, and the related output 'struct timespec'. GNU glibc
defaults as above, also exposing the SO_TIMESTAMPNS_NEW flag to explicitly
use a 64-bit call and 'struct __kernel_timespec'. Since these are not
exposed or needed with musl libc, their use in tc_redirect.c leads to
compile errors building for mips64el/musl:
tc_redirect.c: In function 'rcv_tstamp':
tc_redirect.c:425:32: error: 'SO_TIMESTAMPNS_NEW' undeclared (first use in this function); did you mean 'SO_TIMESTAMPNS'?
425 | cmsg->cmsg_type == SO_TIMESTAMPNS_NEW)
| ^~~~~~~~~~~~~~~~~~
| SO_TIMESTAMPNS
tc_redirect.c:425:32: note: each undeclared identifier is reported only once for each function it appears in
tc_redirect.c: In function 'test_inet_dtime':
tc_redirect.c:491:49: error: 'SO_TIMESTAMPNS_NEW' undeclared (first use in this function); did you mean 'SO_TIMESTAMPNS'?
491 | err = setsockopt(listen_fd, SOL_SOCKET, SO_TIMESTAMPNS_NEW,
| ^~~~~~~~~~~~~~~~~~
| SO_TIMESTAMPNS
However, using SO_TIMESTAMPNS_NEW isn't strictly needed, nor is Y2038 being
explicitly tested. The timestamp checks in tc_redirect.c are simple: the
packet receive timestamp is non-zero and processed/handled in less than 5
seconds.
Switch to using the standard setsockopt() call and SO_TIMESTAMPNS option to
ensure compatibility across glibc and musl libc. In the worst-case, there
is a 5-second window 14 years from now where tc_redirect tests may fail on
32-bit systems. However, we should reasonably expect glibc to adopt a
64-bit mandate rather than the current "opt-in" policy before the Y2038
roll-over.
Fixes: ce6f6cffaeaa ("selftests/bpf: Wait for the netstamp_needed_key static key to be turned on")
Fixes: c803475fd8dd ("bpf: selftests: test skb->tstamp in redirect_neigh")
Signed-off-by: Tony Ambardar <tony.ambardar@xxxxxxxxx>
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/031d656c058b4e55ceae56ef49c4e1729b5090f3.1722244708.git.tony.ambardar@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c
index af3c31f82a8ae..5a64017335875 100644
--- a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c
+++ b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c
@@ -421,7 +421,7 @@ static int set_forwarding(bool enable)
static int __rcv_tstamp(int fd, const char *expected, size_t s, __u64 *tstamp)
{
- struct __kernel_timespec pkt_ts = {};
+ struct timespec pkt_ts = {};
char ctl[CMSG_SPACE(sizeof(pkt_ts))];
struct timespec now_ts;
struct msghdr msg = {};
@@ -445,7 +445,7 @@ static int __rcv_tstamp(int fd, const char *expected, size_t s, __u64 *tstamp)
cmsg = CMSG_FIRSTHDR(&msg);
if (cmsg && cmsg->cmsg_level == SOL_SOCKET &&
- cmsg->cmsg_type == SO_TIMESTAMPNS_NEW)
+ cmsg->cmsg_type == SO_TIMESTAMPNS)
memcpy(&pkt_ts, CMSG_DATA(cmsg), sizeof(pkt_ts));
pkt_ns = pkt_ts.tv_sec * NSEC_PER_SEC + pkt_ts.tv_nsec;
@@ -487,9 +487,9 @@ static int wait_netstamp_needed_key(void)
if (!ASSERT_GE(srv_fd, 0, "start_server"))
goto done;
- err = setsockopt(srv_fd, SOL_SOCKET, SO_TIMESTAMPNS_NEW,
+ err = setsockopt(srv_fd, SOL_SOCKET, SO_TIMESTAMPNS,
&opt, sizeof(opt));
- if (!ASSERT_OK(err, "setsockopt(SO_TIMESTAMPNS_NEW)"))
+ if (!ASSERT_OK(err, "setsockopt(SO_TIMESTAMPNS)"))
goto done;
cli_fd = connect_to_fd(srv_fd, TIMEOUT_MILLIS);
@@ -571,9 +571,9 @@ static void test_inet_dtime(int family, int type, const char *addr, __u16 port)
return;
/* Ensure the kernel puts the (rcv) timestamp for all skb */
- err = setsockopt(listen_fd, SOL_SOCKET, SO_TIMESTAMPNS_NEW,
+ err = setsockopt(listen_fd, SOL_SOCKET, SO_TIMESTAMPNS,
&opt, sizeof(opt));
- if (!ASSERT_OK(err, "setsockopt(SO_TIMESTAMPNS_NEW)"))
+ if (!ASSERT_OK(err, "setsockopt(SO_TIMESTAMPNS)"))
goto done;
if (type == SOCK_STREAM) {
