selftests/xsk: Introduce mmap_size in umem struct

UMEM teardown currently recomputes the munmap() length from frame
geometry, shared-UMEM adjustment, and hugepage rounding. This duplicates
setup-time logic in cleanup and relies on re-deriving the mapping size
instead of using the size originally established for the mapping.

Store the final mapping length in xsk_umem_info as mmap_size when the
UMEM mapping is created, and use that value during teardown.

Also join the RX worker thread before cleanup in the single-thread
path. This establishes synchronization before reading umem->mmap_size
in teardown and avoids a potential visibility race.

This removes duplicated size arithmetic in cleanup and makes munmap()
use the canonical mapping size recorded at setup time.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Tushar Vyavahare <tushar.vyavahare@intel.com>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://patch.msgid.link/20260608130938.958793-5-tushar.vyavahare@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/tools/testing/selftests/bpf/prog_tests/test_xsk.c b/tools/testing/selftests/bpf/prog_tests/test_xsk.c
index 17a467a7dd7f64f9d7633a935d3fafb968dee6e7..72875071d4f1249d475b670058aa4991a31fe317 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/test_xsk.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_xsk.c
@@ -1581,7 +1581,7 @@ static int thread_common_ops(struct test_spec *test, struct ifobject *ifobject)
        struct xsk_umem_info *umem = ifobject->xsk->umem;
        LIBBPF_OPTS(bpf_xdp_query_opts, opts);
        int mmap_flags;
-       u64 umem_sz;
+       u64 umem_sz, mmap_sz;
        void *bufs;
        int ret;
        u32 i;
@@ -1595,10 +1595,15 @@ static int thread_common_ops(struct test_spec *test, struct ifobject *ifobject)
        if (ifobject->shared_umem)
                umem_sz *= 2;
 
-       bufs = mmap(NULL, umem_sz, PROT_READ | PROT_WRITE, mmap_flags, -1, 0);
+       mmap_sz = umem->unaligned_mode ?
+               ceil_u64(umem_sz, HUGEPAGE_SIZE) * HUGEPAGE_SIZE : umem_sz;
+
+       bufs = mmap(NULL, mmap_sz, PROT_READ | PROT_WRITE, mmap_flags, -1, 0);
        if (bufs == MAP_FAILED)
                return -errno;
 
+       umem->mmap_size = mmap_sz;
+
        ret = xsk_configure_umem(ifobject, umem, bufs, umem_sz);
        if (ret)
                return ret;
@@ -1706,15 +1711,9 @@ void *worker_testapp_validate_rx(void *arg)
 static void testapp_clean_xsk_umem(struct ifobject *ifobj)
 {
        struct xsk_umem_info *umem = ifobj->xsk->umem;
-       u64 umem_sz = umem_size(umem);
-
-       if (ifobj->shared_umem)
-               umem_sz *= 2;
-
-       umem_sz = ceil_u64(umem_sz, HUGEPAGE_SIZE) * HUGEPAGE_SIZE;
 
        xsk_umem__delete(umem->umem);
-       munmap(umem->buffer, umem_sz);
+       munmap(umem->buffer, umem->mmap_size);
 }
 
 static void handler(int signum)
@@ -1857,8 +1856,7 @@ static int __testapp_validate_traffic(struct test_spec *test, struct ifobject *i
 
        if (!ifobj2)
                pthread_kill(t0, SIGUSR1);
-       else
-               pthread_join(t0, NULL);
+       pthread_join(t0, NULL);
 
        if (test->total_steps == test->current_step || test->fail) {
                clean_sockets(test, ifobj1);

diff --git a/tools/testing/selftests/bpf/prog_tests/test_xsk.h b/tools/testing/selftests/bpf/prog_tests/test_xsk.h
index 99003995d7c3d4d911f4f1bab3c13c4035c09e2b..4313d0d87235f225fdf74d0d0c87763304dc7d44 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/test_xsk.h
+++ b/tools/testing/selftests/bpf/prog_tests/test_xsk.h
@@ -103,6 +103,7 @@ struct xsk_umem_info {
        struct xsk_ring_cons cq;
        struct xsk_umem *umem;
        u64 next_buffer;
+       u64 mmap_size;
        u32 num_frames;
        u32 frame_headroom;
        void *buffer;