mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-05-16 04:21:09 -04:00
Code Issues Packages Projects Releases Wiki Activity

selftests/bpf: Fix sockmap_multi_channels reliability

Browse Source 
Previously I added a FIONREAD test for sockmap, but it can occasionally
fail in CI [1].

The test sends 10 bytes in two segments (2 + 8). For UDP, FIONREAD only
reports the length of the first datagram, not the total queued data.
The original code used recv_timeout() expecting all 10 bytes, but under
high system load, the second datagram may not yet be processed by the
protocol stack, so recv would only return the first 2-byte datagram,
causing a size mismatch failure.

Fix this by receiving exactly the expected bytes (matching FIONREAD) in
the first recv. The remaining datagram is then consumed in a second recv
block, which is only reachable for UDP since TCP's expected already
equals sizeof(buf).

Test:
./test_progs -a sockmap_basic
410/1   sockmap_basic/sockmap create_update_free:OK
...
Summary: 1/35 PASSED, 0 SKIPPED, 0 FAILED

[1] https://github.com/kernel-patches/bpf/actions/runs/22919385910/job/66515395423

Cc: Jiayuan Chen <jiayuan.chen@linux.dev>
Fixes: 17e2ce02bf ("selftests/bpf: Add tests for FIONREAD and copied_seq")
Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com>
Link: https://lore.kernel.org/r/20260312072549.6766-1-jiayuan.chen@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Jiayuan Chen
2026-03-12 15:25:44 +08:00
committed by Alexei Starovoitov
parent 2790db208b
commit d9d7125e44
1 changed files with 15 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
View File

@@ -1298,10 +1298,23 @@ static void test_sockmap_multi_channels(int sotype)
avail = wait_for_fionread(p1, expected, IO_TIMEOUT_SEC);
ASSERT_EQ(avail, expected, "ioctl(FIONREAD) full return");
recvd = recv_timeout(p1, rcv, sizeof(rcv), MSG_DONTWAIT, 1);
if (!ASSERT_EQ(recvd, sizeof(buf), "recv_timeout(p1)") ||
recvd = recv_timeout(p1, rcv, expected, MSG_DONTWAIT, 1);
if (!ASSERT_EQ(recvd, expected, "recv_timeout(p1)") ||
!ASSERT_OK(memcmp(buf, rcv, recvd), "data mismatch"))
goto end;
/* process remaining data for udp if secondary data is available */
expected = sizeof(buf) - expected;
if (expected) {
avail = wait_for_fionread(p1, expected, IO_TIMEOUT_SEC);
ASSERT_EQ(avail, expected, "second ioctl(FIONREAD) full return");
recvd = recv_timeout(p1, rcv, expected, MSG_DONTWAIT, 1);
if (!ASSERT_EQ(recvd, expected, "second recv_timeout(p1)") ||
!ASSERT_OK(memcmp(buf + sizeof(buf) - expected, rcv, recvd),
"second data mismatch"))
goto end;
}
end:
if (c0 >= 0)
close(c0);