From: Stanislav Fomichev <sdf@google.com>
To: bpf@vger.kernel.org
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
martin.lau@linux.dev, song@kernel.org, yhs@fb.com,
john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
haoluo@google.com, jolsa@kernel.org
Subject: [PATCH bpf-next] selftests/bpf: Try to address xdp_metadata crashes
Date: Mon, 30 Jan 2023 13:51:37 -0800 [thread overview]
Message-ID: <20230130215137.3473320-1-sdf@google.com> (raw)
Commit e04ce9f4040b ("selftests/bpf: Make crashes more debuggable in
test_progs") hasn't uncovered anything interesting besides
confirming that the test passes successfully, but crashes eventually [0].
I'm assuming the crashes are coming from something overriding
the stack/heap. Probably from the xsk misuse. So I'm trying
a bunch of things to address that:
- More debugging with real memory pointers for the queues/umem
- To confirm that everything is sane
- Set proper tx/fill ring sizes
- In particular, fill ring wasn't fully initialized, but I'm
assuming no packets should be flowing there regardless
- Do the same for xdp_hw_metadata
- Don't refill on tx completion; instead, only ack it
0: https://github.com/kernel-patches/bpf/actions/runs/4032162075/jobs/6931951300
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
.../selftests/bpf/prog_tests/xdp_metadata.c | 36 +++++++++++++------
tools/testing/selftests/bpf/xdp_hw_metadata.c | 4 +--
2 files changed, 28 insertions(+), 12 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
index e033d48288c0..453b4045a9d1 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
@@ -54,11 +54,11 @@ static int open_xsk(int ifindex, struct xsk *xsk)
int mmap_flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE;
const struct xsk_socket_config socket_config = {
.rx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS,
- .tx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS,
+ .tx_size = UMEM_NUM / 2,
.bind_flags = XDP_COPY,
};
const struct xsk_umem_config umem_config = {
- .fill_size = XSK_RING_PROD__DEFAULT_NUM_DESCS,
+ .fill_size = UMEM_NUM / 2,
.comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS,
.frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE,
.flags = XDP_UMEM_UNALIGNED_CHUNK_FLAG,
@@ -88,13 +88,24 @@ static int open_xsk(int ifindex, struct xsk *xsk)
if (!ASSERT_OK(ret, "xsk_socket__create"))
return ret;
+ printf("%p: umem=<%p..%p>\n", xsk, xsk->umem_area, xsk->umem_area + UMEM_SIZE);
+ printf("%p: fill=<%p..%p>\n", xsk, xsk->fill.ring,
+ xsk->fill.ring + xsk->fill.size * sizeof(__u64));
+ printf("%p: comp=<%p..%p>\n", xsk, xsk->comp.ring,
+ xsk->comp.ring + xsk->comp.size * sizeof(__u64));
+ printf("%p: rx=<%p..%p>\n", xsk, xsk->rx.ring,
+ xsk->rx.ring + xsk->rx.size * sizeof(struct xdp_desc));
+ printf("%p: tx=<%p..%p>\n", xsk, xsk->tx.ring,
+ xsk->tx.ring + xsk->tx.size * sizeof(struct xdp_desc));
+
/* First half of umem is for TX. This way address matches 1-to-1
* to the completion queue index.
*/
for (i = 0; i < UMEM_NUM / 2; i++) {
addr = i * UMEM_FRAME_SIZE;
- printf("%p: tx_desc[%d] -> %lx\n", xsk, i, addr);
+ printf("%p: tx_desc[%d] -> %lx (%p)\n", xsk, i, addr,
+ xsk_umem__get_data(xsk->umem_area, addr));
}
/* Second half of umem is for RX. */
@@ -107,7 +118,10 @@ static int open_xsk(int ifindex, struct xsk *xsk)
for (i = 0; i < UMEM_NUM / 2; i++) {
addr = (UMEM_NUM / 2 + i) * UMEM_FRAME_SIZE;
- printf("%p: rx_desc[%d] -> %lx\n", xsk, i, addr);
+ printf("%p: rx_desc[%d] -> %lx (%p)\n", xsk, i, addr,
+ xsk_umem__get_data(xsk->umem_area, addr));
+ printf("%p: fill %lx at %p\n", xsk, addr,
+ xsk_ring_prod__fill_addr(&xsk->fill, i));
*xsk_ring_prod__fill_addr(&xsk->fill, i) = addr;
}
xsk_ring_prod__submit(&xsk->fill, ret);
@@ -159,6 +173,7 @@ static int generate_packet(struct xsk *xsk, __u16 dst_port)
tx_desc->addr = idx % (UMEM_NUM / 2) * UMEM_FRAME_SIZE;
printf("%p: tx_desc[%u]->addr=%llx\n", xsk, idx, tx_desc->addr);
data = xsk_umem__get_data(xsk->umem_area, tx_desc->addr);
+ printf("%p: tx %llx (%p) at %p\n", xsk, tx_desc->addr, data, tx_desc);
eth = data;
iph = (void *)(eth + 1);
@@ -205,9 +220,8 @@ static void complete_tx(struct xsk *xsk)
if (ASSERT_EQ(xsk_ring_cons__peek(&xsk->comp, 1, &idx), 1, "xsk_ring_cons__peek")) {
addr = *xsk_ring_cons__comp_addr(&xsk->comp, idx);
- printf("%p: refill idx=%u addr=%llx\n", xsk, idx, addr);
- *xsk_ring_prod__fill_addr(&xsk->fill, idx) = addr;
- xsk_ring_prod__submit(&xsk->fill, 1);
+ printf("%p: complete tx idx=%u addr=%llx\n", xsk, idx, addr);
+ xsk_ring_cons__release(&xsk->comp, 1);
}
}
@@ -216,7 +230,9 @@ static void refill_rx(struct xsk *xsk, __u64 addr)
__u32 idx;
if (ASSERT_EQ(xsk_ring_prod__reserve(&xsk->fill, 1, &idx), 1, "xsk_ring_prod__reserve")) {
- printf("%p: complete idx=%u addr=%llx\n", xsk, idx, addr);
+ printf("%p: complete rx idx=%u addr=%llx\n", xsk, idx, addr);
+ printf("%p: fill %llx at %p\n", xsk, addr,
+ xsk_ring_prod__fill_addr(&xsk->fill, idx));
*xsk_ring_prod__fill_addr(&xsk->fill, idx) = addr;
xsk_ring_prod__submit(&xsk->fill, 1);
}
@@ -253,8 +269,8 @@ static int verify_xsk_metadata(struct xsk *xsk)
rx_desc = xsk_ring_cons__rx_desc(&xsk->rx, idx);
comp_addr = xsk_umem__extract_addr(rx_desc->addr);
addr = xsk_umem__add_offset_to_addr(rx_desc->addr);
- printf("%p: rx_desc[%u]->addr=%llx addr=%llx comp_addr=%llx\n",
- xsk, idx, rx_desc->addr, addr, comp_addr);
+ printf("%p: rx_desc[%u]->addr=%llx (%p) addr=%llx comp_addr=%llx\n",
+ xsk, idx, rx_desc->addr, rx_desc, addr, comp_addr);
data = xsk_umem__get_data(xsk->umem_area, addr);
/* Make sure we got the packet offset correctly. */
diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c b/tools/testing/selftests/bpf/xdp_hw_metadata.c
index 3823b1c499cc..6d715f85ea20 100644
--- a/tools/testing/selftests/bpf/xdp_hw_metadata.c
+++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c
@@ -59,11 +59,11 @@ static int open_xsk(int ifindex, struct xsk *xsk, __u32 queue_id)
int mmap_flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE;
const struct xsk_socket_config socket_config = {
.rx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS,
- .tx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS,
+ .tx_size = UMEM_NUM / 2,
.bind_flags = XDP_COPY,
};
const struct xsk_umem_config umem_config = {
- .fill_size = XSK_RING_PROD__DEFAULT_NUM_DESCS,
+ .fill_size = UMEM_NUM / 2,
.comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS,
.frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE,
.flags = XDP_UMEM_UNALIGNED_CHUNK_FLAG,
--
2.39.1.456.gfc5497dd1b-goog
next reply other threads:[~2023-01-30 21:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-30 21:51 Stanislav Fomichev [this message]
2023-01-31 5:41 ` [PATCH bpf-next] selftests/bpf: Try to address xdp_metadata crashes Alexei Starovoitov
2023-01-31 18:07 ` Stanislav Fomichev
2023-02-01 23:28 ` Stanislav Fomichev
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