| Message ID | 20240319050302.1085006-2-josef@netflix.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [V3,bpf-next,1/2] bpf: add bpf_task_get_cgroup kfunc | expand |
On Mon, Mar 18, 2024 at 11:03:02PM -0600, Jose Fernandez wrote: > This patch adds a selftest for the `bpf_task_get_cgroup` kfunc. The test > focuses on the use case of obtaining the cgroup ID of the previous task > in a `sched_switch` tracepoint. > > The selftest involves creating a test cgroup, attaching a BPF program > that utilizes the `bpf_task_get_cgroup` during a `sched_switch` > tracepoint, and validating that the obtained cgroup ID for the previous > task matches the expected cgroup ID. > > Signed-off-by: Jose Fernandez <josef@netflix.com> > Reviewed-by: Tycho Andersen <tycho@tycho.pizza> Acked-by: Jiri Olsa <jolsa@kernel.org> jirka > --- > V2 -> v3: Use _open_and_load(), usleep helper, and drop map usage > V1 -> V2: Refactor test to work with a cgroup pointer instead of the ID > > .../bpf/prog_tests/task_get_cgroup.c | 43 +++++++++++++++++++ > .../bpf/progs/test_task_get_cgroup.c | 32 ++++++++++++++ > 2 files changed, 75 insertions(+) > create mode 100644 tools/testing/selftests/bpf/prog_tests/task_get_cgroup.c > create mode 100644 tools/testing/selftests/bpf/progs/test_task_get_cgroup.c > > diff --git a/tools/testing/selftests/bpf/prog_tests/task_get_cgroup.c b/tools/testing/selftests/bpf/prog_tests/task_get_cgroup.c > new file mode 100644 > index 000000000000..031623067e7e > --- /dev/null > +++ b/tools/testing/selftests/bpf/prog_tests/task_get_cgroup.c > @@ -0,0 +1,43 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// Copyright 2024 Netflix, Inc. > + > +#include <test_progs.h> > +#include <cgroup_helpers.h> > +#include "test_task_get_cgroup.skel.h" > +#include <unistd.h> > + > +#define TEST_CGROUP "/test-task-get-cgroup/" > + > +void test_task_get_cgroup(void) > +{ > + struct test_task_get_cgroup *skel; > + int err, fd; > + __u64 expected_cgroup_id; > + > + fd = test__join_cgroup(TEST_CGROUP); > + if (!ASSERT_OK(fd < 0, "test_join_cgroup_TEST_CGROUP")) > + return; > + > + skel = test_task_get_cgroup__open_and_load(); > + if (!ASSERT_OK_PTR(skel, "test_task_get_cgroup__open_and_load")) > + goto cleanup; > + > + err = test_task_get_cgroup__attach(skel); > + if (!ASSERT_OK(err, "test_task_get_cgroup__attach")) > + goto cleanup; > + > + skel->bss->pid = getpid(); > + expected_cgroup_id = get_cgroup_id(TEST_CGROUP); > + if (!ASSERT_GT(expected_cgroup_id, 0, "get_cgroup_id")) > + goto cleanup; > + > + /* Trigger nanosleep to enter the sched_switch tracepoint */ > + /* The previous task should be this process */ > + usleep(100); > + > + ASSERT_EQ(skel->bss->cgroup_id, expected_cgroup_id, "cgroup_id"); > + > +cleanup: > + test_task_get_cgroup__destroy(skel); > + close(fd); > +} > diff --git a/tools/testing/selftests/bpf/progs/test_task_get_cgroup.c b/tools/testing/selftests/bpf/progs/test_task_get_cgroup.c > new file mode 100644 > index 000000000000..30d4499c6bc5 > --- /dev/null > +++ b/tools/testing/selftests/bpf/progs/test_task_get_cgroup.c > @@ -0,0 +1,32 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// Copyright 2024 Netflix, Inc. > + > +#include "vmlinux.h" > +#include <bpf/bpf_helpers.h> > +#include <bpf/bpf_tracing.h> > + > +struct cgroup *bpf_task_get_cgroup(struct task_struct *task) __ksym; > +void bpf_cgroup_release(struct cgroup *cgrp) __ksym; > + > +int pid = 0; > +u64 cgroup_id = 0; > + > +SEC("tp_btf/sched_switch") > +int BPF_PROG(sched_switch, bool preempt, struct task_struct *prev, > + struct task_struct *next) > +{ > + struct cgroup *cgrp; > + > + if (prev->pid != pid) > + return 0; > + > + cgrp = bpf_task_get_cgroup(prev); > + if (cgrp == NULL) > + return 0; > + cgroup_id = cgrp->kn->id; > + > + bpf_cgroup_release(cgrp); > + return 0; > +} > + > +char _license[] SEC("license") = "GPL"; > -- > 2.40.1 >
diff --git a/tools/testing/selftests/bpf/prog_tests/task_get_cgroup.c b/tools/testing/selftests/bpf/prog_tests/task_get_cgroup.c new file mode 100644 index 000000000000..031623067e7e --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/task_get_cgroup.c @@ -0,0 +1,43 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright 2024 Netflix, Inc. + +#include <test_progs.h> +#include <cgroup_helpers.h> +#include "test_task_get_cgroup.skel.h" +#include <unistd.h> + +#define TEST_CGROUP "/test-task-get-cgroup/" + +void test_task_get_cgroup(void) +{ + struct test_task_get_cgroup *skel; + int err, fd; + __u64 expected_cgroup_id; + + fd = test__join_cgroup(TEST_CGROUP); + if (!ASSERT_OK(fd < 0, "test_join_cgroup_TEST_CGROUP")) + return; + + skel = test_task_get_cgroup__open_and_load(); + if (!ASSERT_OK_PTR(skel, "test_task_get_cgroup__open_and_load")) + goto cleanup; + + err = test_task_get_cgroup__attach(skel); + if (!ASSERT_OK(err, "test_task_get_cgroup__attach")) + goto cleanup; + + skel->bss->pid = getpid(); + expected_cgroup_id = get_cgroup_id(TEST_CGROUP); + if (!ASSERT_GT(expected_cgroup_id, 0, "get_cgroup_id")) + goto cleanup; + + /* Trigger nanosleep to enter the sched_switch tracepoint */ + /* The previous task should be this process */ + usleep(100); + + ASSERT_EQ(skel->bss->cgroup_id, expected_cgroup_id, "cgroup_id"); + +cleanup: + test_task_get_cgroup__destroy(skel); + close(fd); +} diff --git a/tools/testing/selftests/bpf/progs/test_task_get_cgroup.c b/tools/testing/selftests/bpf/progs/test_task_get_cgroup.c new file mode 100644 index 000000000000..30d4499c6bc5 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_task_get_cgroup.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright 2024 Netflix, Inc. + +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +struct cgroup *bpf_task_get_cgroup(struct task_struct *task) __ksym; +void bpf_cgroup_release(struct cgroup *cgrp) __ksym; + +int pid = 0; +u64 cgroup_id = 0; + +SEC("tp_btf/sched_switch") +int BPF_PROG(sched_switch, bool preempt, struct task_struct *prev, + struct task_struct *next) +{ + struct cgroup *cgrp; + + if (prev->pid != pid) + return 0; + + cgrp = bpf_task_get_cgroup(prev); + if (cgrp == NULL) + return 0; + cgroup_id = cgrp->kn->id; + + bpf_cgroup_release(cgrp); + return 0; +} + +char _license[] SEC("license") = "GPL";