linux-stable/tools/testing/selftests/bpf/prog_tests/trace_ext.c
Jiri Olsa 17d3f38675 selftests/bpf: Adding test for arg dereference in extension trace
Adding test that setup following program:

  SEC("classifier/test_pkt_md_access")
  int test_pkt_md_access(struct __sk_buff *skb)

with its extension:

  SEC("freplace/test_pkt_md_access")
  int test_pkt_md_access_new(struct __sk_buff *skb)

and tracing that extension with:

  SEC("fentry/test_pkt_md_access_new")
  int BPF_PROG(fentry, struct sk_buff *skb)

The test verifies that the tracing program can
dereference skb argument properly.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/160138355603.48470.9072073357530773228.stgit@toke.dk
2020-09-29 13:09:24 -07:00

111 lines
3.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <test_progs.h>
#include <network_helpers.h>
#include <sys/stat.h>
#include <linux/sched.h>
#include <sys/syscall.h>
#include "test_pkt_md_access.skel.h"
#include "test_trace_ext.skel.h"
#include "test_trace_ext_tracing.skel.h"
static __u32 duration;
void test_trace_ext(void)
{
struct test_pkt_md_access *skel_pkt = NULL;
struct test_trace_ext_tracing *skel_trace = NULL;
struct test_trace_ext_tracing__bss *bss_trace;
struct test_trace_ext *skel_ext = NULL;
struct test_trace_ext__bss *bss_ext;
int err, pkt_fd, ext_fd;
struct bpf_program *prog;
char buf[100];
__u32 retval;
__u64 len;
/* open/load/attach test_pkt_md_access */
skel_pkt = test_pkt_md_access__open_and_load();
if (CHECK(!skel_pkt, "setup", "classifier/test_pkt_md_access open failed\n"))
goto cleanup;
err = test_pkt_md_access__attach(skel_pkt);
if (CHECK(err, "setup", "classifier/test_pkt_md_access attach failed: %d\n", err))
goto cleanup;
prog = skel_pkt->progs.test_pkt_md_access;
pkt_fd = bpf_program__fd(prog);
/* open extension */
skel_ext = test_trace_ext__open();
if (CHECK(!skel_ext, "setup", "freplace/test_pkt_md_access open failed\n"))
goto cleanup;
/* set extension's attach target - test_pkt_md_access */
prog = skel_ext->progs.test_pkt_md_access_new;
bpf_program__set_attach_target(prog, pkt_fd, "test_pkt_md_access");
/* load/attach extension */
err = test_trace_ext__load(skel_ext);
if (CHECK(err, "setup", "freplace/test_pkt_md_access load failed\n")) {
libbpf_strerror(err, buf, sizeof(buf));
fprintf(stderr, "%s\n", buf);
goto cleanup;
}
err = test_trace_ext__attach(skel_ext);
if (CHECK(err, "setup", "freplace/test_pkt_md_access attach failed: %d\n", err))
goto cleanup;
prog = skel_ext->progs.test_pkt_md_access_new;
ext_fd = bpf_program__fd(prog);
/* open tracing */
skel_trace = test_trace_ext_tracing__open();
if (CHECK(!skel_trace, "setup", "tracing/test_pkt_md_access_new open failed\n"))
goto cleanup;
/* set tracing's attach target - fentry */
prog = skel_trace->progs.fentry;
bpf_program__set_attach_target(prog, ext_fd, "test_pkt_md_access_new");
/* set tracing's attach target - fexit */
prog = skel_trace->progs.fexit;
bpf_program__set_attach_target(prog, ext_fd, "test_pkt_md_access_new");
/* load/attach tracing */
err = test_trace_ext_tracing__load(skel_trace);
if (CHECK(err, "setup", "tracing/test_pkt_md_access_new load failed\n")) {
libbpf_strerror(err, buf, sizeof(buf));
fprintf(stderr, "%s\n", buf);
goto cleanup;
}
err = test_trace_ext_tracing__attach(skel_trace);
if (CHECK(err, "setup", "tracing/test_pkt_md_access_new attach failed: %d\n", err))
goto cleanup;
/* trigger the test */
err = bpf_prog_test_run(pkt_fd, 1, &pkt_v4, sizeof(pkt_v4),
NULL, NULL, &retval, &duration);
CHECK(err || retval, "run", "err %d errno %d retval %d\n", err, errno, retval);
bss_ext = skel_ext->bss;
bss_trace = skel_trace->bss;
len = bss_ext->ext_called;
CHECK(bss_ext->ext_called == 0,
"check", "failed to trigger freplace/test_pkt_md_access\n");
CHECK(bss_trace->fentry_called != len,
"check", "failed to trigger fentry/test_pkt_md_access_new\n");
CHECK(bss_trace->fexit_called != len,
"check", "failed to trigger fexit/test_pkt_md_access_new\n");
cleanup:
test_trace_ext_tracing__destroy(skel_trace);
test_trace_ext__destroy(skel_ext);
test_pkt_md_access__destroy(skel_pkt);
}