Re: [PATCH bpf-next v2] selftests/bpf: Add a test for attaching a bpf fentry/fexit trace to an XDP program
From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Date: 2020-01-14 16:40:44
Also in:
bpf
On Tue, Jan 14, 2020 at 03:58:16PM +0000, Eelco Chaudron wrote:
quoted hunk ↗ jump to hunk
Add a test that will attach a FENTRY and FEXIT program to the XDP test program. It will also verify data from the XDP context on FENTRY and verifies the return code on exit. Signed-off-by: Eelco Chaudron <echaudro@redhat.com> --- v1 -> v2: - Changed code to use the BPF skeleton - Replace static volatile with global variable in eBPF code .../testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c | 69 ++++++++++++++++++++ .../testing/selftests/bpf/progs/test_xdp_bpf2bpf.c | 44 +++++++++++++ 2 files changed, 113 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.cdiff --git a/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c new file mode 100644 index 000000000000..e6e849df2632 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c@@ -0,0 +1,69 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <test_progs.h> +#include <net/if.h> +#include "test_xdp.skel.h" +#include "test_xdp_bpf2bpf.skel.h" + +void test_xdp_bpf2bpf(void) +{ + + struct test_xdp *pkt_skel = NULL; + struct test_xdp_bpf2bpf *ftrace_skel = NULL; + __u64 *ftrace_res;
Wanted to point out the RCT here but I see that tools/testing/selftests/bpf/prog_tests don't really follow that rule.
+
+ struct vip key4 = {.protocol = 6, .family = AF_INET};
+ struct iptnl_info value4 = {.family = AF_INET};
+ char buf[128];
+ struct iphdr *iph = (void *)buf + sizeof(struct ethhdr);
+ __u32 duration = 0, retval, size;
+ int err, pkt_fd, map_fd;
+
+ /* Load XDP program to introspect */
+ pkt_skel = test_xdp__open_and_load();
+ if (CHECK(!pkt_skel, "pkt_skel_load", "test_xdp skeleton failed\n"))
+ return;
+
+ pkt_fd = bpf_program__fd(pkt_skel->progs._xdp_tx_iptunnel);
+
+ map_fd = bpf_map__fd(pkt_skel->maps.vip2tnl);
+ bpf_map_update_elem(map_fd, &key4, &value4, 0);
+
+ DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts,
+ .attach_prog_fd = pkt_fd,
+ );
+
+ ftrace_skel = test_xdp_bpf2bpf__open_opts(&opts);
+ if (CHECK(!ftrace_skel, "__open", "ftrace skeleton failed\n"))
+ goto out;Hmm do you have here mixed tabs and spaces? Maybe my client messes this line up.
+ + if (CHECK(test_xdp_bpf2bpf__load(ftrace_skel), "__load", "ftrace skeleton failed\n"))
line too long?
+ goto out;
+
+ err = test_xdp_bpf2bpf__attach(ftrace_skel);
+ if (CHECK(err, "ftrace_attach", "ftrace attach failed: %d\n", err))
+ goto out;
+
+ /* Run test program */
+ err = bpf_prog_test_run(pkt_fd, 1, &pkt_v4, sizeof(pkt_v4),
+ buf, &size, &retval, &duration);
+
+ CHECK(err || retval != XDP_TX || size != 74 ||
+ iph->protocol != IPPROTO_IPIP, "ipv4",
+ "err %d errno %d retval %d size %d\n",
+ err, errno, retval, size);
+
+ /* Verify test results */
+ ftrace_res = (__u64 *)ftrace_skel->bss;
+
+ if (CHECK(ftrace_res[0] != if_nametoindex("lo"), "result",
+ "fentry failed err %llu\n", ftrace_res[0]))
+ goto out;
+
+ if (CHECK(ftrace_res[1] != XDP_TX, "result",
+ "fexit failed err %llu\n", ftrace_res[1]))
+ goto out;this goto doesn't really make sense, can be dropped.
quoted hunk ↗ jump to hunk
+ +out: + test_xdp__destroy(pkt_skel); + test_xdp_bpf2bpf__destroy(ftrace_skel); +}diff --git a/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c new file mode 100644 index 000000000000..74c78b30ae07 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c@@ -0,0 +1,44 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/bpf.h> +#include "bpf_helpers.h" +#include "bpf_trace_helpers.h" + +struct net_device { + /* Structure does not need to contain all entries, + * as "preserve_access_index" will use BTF to fix this... + */ + int ifindex; +} __attribute__((preserve_access_index)); + +struct xdp_rxq_info { + /* Structure does not need to contain all entries, + * as "preserve_access_index" will use BTF to fix this... + */ + struct net_device *dev; + __u32 queue_index; +} __attribute__((preserve_access_index)); + +struct xdp_buff { + void *data; + void *data_end; + void *data_meta; + void *data_hard_start; + unsigned long handle; + struct xdp_rxq_info *rxq; +} __attribute__((preserve_access_index)); + +__u64 test_result_fentry = 0; +BPF_TRACE_1("fentry/_xdp_tx_iptunnel", trace_on_entry, + struct xdp_buff *, xdp) +{ + test_result_fentry = xdp->rxq->dev->ifindex; + return 0; +} + +__u64 test_result_fexit = 0; +BPF_TRACE_2("fexit/_xdp_tx_iptunnel", trace_on_exit, + struct xdp_buff*, xdp, int, ret) +{ + test_result_fexit = ret; + return 0; +}