* [PATCH bpf-next v7 1/2] bpf: Add bpf_task_under_cgroup() kfunc
2023-05-06 3:15 [PATCH bpf-next v7 0/2] Introduce a new kfunc of bpf_task_under_cgroup Feng zhou
@ 2023-05-06 3:15 ` Feng zhou
2023-05-06 3:15 ` [PATCH bpf-next v7 2/2] selftests/bpf: Add testcase for bpf_task_under_cgroup Feng zhou
2023-05-06 21:10 ` [PATCH bpf-next v7 0/2] Introduce a new kfunc of bpf_task_under_cgroup patchwork-bot+netdevbpf
2 siblings, 0 replies; 4+ messages in thread
From: Feng zhou @ 2023-05-06 3:15 UTC (permalink / raw)
To: martin.lau, ast, daniel, andrii, song, yhs, john.fastabend,
kpsingh, sdf, haoluo, jolsa, davem, edumazet, kuba, pabeni,
mykolal, shuah
Cc: bpf, linux-kernel, netdev, linux-kselftest, yangzhenze,
wangdongdong.6, zhoufeng.zf
From: Feng Zhou <zhoufeng.zf@bytedance.com>
Add a kfunc that's similar to the bpf_current_task_under_cgroup.
The difference is that it is a designated task.
When hook sched related functions, sometimes it is necessary to
specify a task instead of the current task.
Signed-off-by: Feng Zhou <zhoufeng.zf@bytedance.com>
Acked-by: Yonghong Song <yhs@fb.com>
---
kernel/bpf/helpers.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index bb6b4637ebf2..a128fe0ab2d0 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -2149,6 +2149,22 @@ __bpf_kfunc struct cgroup *bpf_cgroup_from_id(u64 cgid)
return NULL;
return cgrp;
}
+
+/**
+ * bpf_task_under_cgroup - wrap task_under_cgroup_hierarchy() as a kfunc, test
+ * task's membership of cgroup ancestry.
+ * @task: the task to be tested
+ * @ancestor: possible ancestor of @task's cgroup
+ *
+ * Tests whether @task's default cgroup hierarchy is a descendant of @ancestor.
+ * It follows all the same rules as cgroup_is_descendant, and only applies
+ * to the default hierarchy.
+ */
+__bpf_kfunc long bpf_task_under_cgroup(struct task_struct *task,
+ struct cgroup *ancestor)
+{
+ return task_under_cgroup_hierarchy(task, ancestor);
+}
#endif /* CONFIG_CGROUPS */
/**
@@ -2400,6 +2416,7 @@ BTF_ID_FLAGS(func, bpf_cgroup_acquire, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_cgroup_release, KF_RELEASE)
BTF_ID_FLAGS(func, bpf_cgroup_ancestor, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_cgroup_from_id, KF_ACQUIRE | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_task_under_cgroup, KF_RCU)
#endif
BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL)
BTF_SET8_END(generic_btf_ids)
--
2.20.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH bpf-next v7 2/2] selftests/bpf: Add testcase for bpf_task_under_cgroup
2023-05-06 3:15 [PATCH bpf-next v7 0/2] Introduce a new kfunc of bpf_task_under_cgroup Feng zhou
2023-05-06 3:15 ` [PATCH bpf-next v7 1/2] bpf: Add bpf_task_under_cgroup() kfunc Feng zhou
@ 2023-05-06 3:15 ` Feng zhou
2023-05-06 21:10 ` [PATCH bpf-next v7 0/2] Introduce a new kfunc of bpf_task_under_cgroup patchwork-bot+netdevbpf
2 siblings, 0 replies; 4+ messages in thread
From: Feng zhou @ 2023-05-06 3:15 UTC (permalink / raw)
To: martin.lau, ast, daniel, andrii, song, yhs, john.fastabend,
kpsingh, sdf, haoluo, jolsa, davem, edumazet, kuba, pabeni,
mykolal, shuah
Cc: bpf, linux-kernel, netdev, linux-kselftest, yangzhenze,
wangdongdong.6, zhoufeng.zf
From: Feng Zhou <zhoufeng.zf@bytedance.com>
test_progs:
Tests new kfunc bpf_task_under_cgroup().
The bpf program saves the new task's pid within a given cgroup to
the remote_pid, which is convenient for the user-mode program to
verify the test correctness.
The user-mode program creates its own mount namespace, and mounts the
cgroupsv2 hierarchy in there, call the fork syscall, then check if
remote_pid and local_pid are unequal.
Signed-off-by: Feng Zhou <zhoufeng.zf@bytedance.com>
Acked-by: Yonghong Song <yhs@fb.com>
---
tools/testing/selftests/bpf/DENYLIST.s390x | 1 +
.../bpf/prog_tests/task_under_cgroup.c | 53 +++++++++++++++++++
.../bpf/progs/test_task_under_cgroup.c | 51 ++++++++++++++++++
3 files changed, 105 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c
create mode 100644 tools/testing/selftests/bpf/progs/test_task_under_cgroup.c
diff --git a/tools/testing/selftests/bpf/DENYLIST.s390x b/tools/testing/selftests/bpf/DENYLIST.s390x
index c7463f3ec3c0..5061d9e24c16 100644
--- a/tools/testing/selftests/bpf/DENYLIST.s390x
+++ b/tools/testing/selftests/bpf/DENYLIST.s390x
@@ -26,3 +26,4 @@ user_ringbuf # failed to find kernel BTF type ID of
verif_stats # trace_vprintk__open_and_load unexpected error: -9 (?)
xdp_bonding # failed to auto-attach program 'trace_on_entry': -524 (trampoline)
xdp_metadata # JIT does not support calling kernel function (kfunc)
+test_task_under_cgroup # JIT does not support calling kernel function (kfunc)
diff --git a/tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c b/tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c
new file mode 100644
index 000000000000..4224727fb364
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Bytedance */
+
+#include <sys/syscall.h>
+#include <test_progs.h>
+#include <cgroup_helpers.h>
+#include "test_task_under_cgroup.skel.h"
+
+#define FOO "/foo"
+
+void test_task_under_cgroup(void)
+{
+ struct test_task_under_cgroup *skel;
+ int ret, foo;
+ pid_t pid;
+
+ foo = test__join_cgroup(FOO);
+ if (!ASSERT_OK(foo < 0, "cgroup_join_foo"))
+ return;
+
+ skel = test_task_under_cgroup__open();
+ if (!ASSERT_OK_PTR(skel, "test_task_under_cgroup__open"))
+ goto cleanup;
+
+ skel->rodata->local_pid = getpid();
+ skel->bss->remote_pid = getpid();
+ skel->rodata->cgid = get_cgroup_id(FOO);
+
+ ret = test_task_under_cgroup__load(skel);
+ if (!ASSERT_OK(ret, "test_task_under_cgroup__load"))
+ goto cleanup;
+
+ ret = test_task_under_cgroup__attach(skel);
+ if (!ASSERT_OK(ret, "test_task_under_cgroup__attach"))
+ goto cleanup;
+
+ pid = fork();
+ if (pid == 0)
+ exit(0);
+
+ ret = (pid == -1);
+ if (ASSERT_OK(ret, "fork process"))
+ wait(NULL);
+
+ test_task_under_cgroup__detach(skel);
+
+ ASSERT_NEQ(skel->bss->remote_pid, skel->rodata->local_pid,
+ "test task_under_cgroup");
+
+cleanup:
+ test_task_under_cgroup__destroy(skel);
+ close(foo);
+}
diff --git a/tools/testing/selftests/bpf/progs/test_task_under_cgroup.c b/tools/testing/selftests/bpf/progs/test_task_under_cgroup.c
new file mode 100644
index 000000000000..56cdc0a553f0
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_task_under_cgroup.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Bytedance */
+
+#include <vmlinux.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_helpers.h>
+
+#include "bpf_misc.h"
+
+struct cgroup *bpf_cgroup_from_id(u64 cgid) __ksym;
+long bpf_task_under_cgroup(struct task_struct *task, struct cgroup *ancestor) __ksym;
+void bpf_cgroup_release(struct cgroup *p) __ksym;
+struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym;
+void bpf_task_release(struct task_struct *p) __ksym;
+
+const volatile int local_pid;
+const volatile __u64 cgid;
+int remote_pid;
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(handle__task_newtask, struct task_struct *task, u64 clone_flags)
+{
+ struct cgroup *cgrp = NULL;
+ struct task_struct *acquired;
+
+ if (local_pid != (bpf_get_current_pid_tgid() >> 32))
+ return 0;
+
+ acquired = bpf_task_acquire(task);
+ if (!acquired)
+ return 0;
+
+ if (local_pid == acquired->tgid)
+ goto out;
+
+ cgrp = bpf_cgroup_from_id(cgid);
+ if (!cgrp)
+ goto out;
+
+ if (bpf_task_under_cgroup(acquired, cgrp))
+ remote_pid = acquired->tgid;
+
+out:
+ if (cgrp)
+ bpf_cgroup_release(cgrp);
+ bpf_task_release(acquired);
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
--
2.20.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH bpf-next v7 0/2] Introduce a new kfunc of bpf_task_under_cgroup
2023-05-06 3:15 [PATCH bpf-next v7 0/2] Introduce a new kfunc of bpf_task_under_cgroup Feng zhou
2023-05-06 3:15 ` [PATCH bpf-next v7 1/2] bpf: Add bpf_task_under_cgroup() kfunc Feng zhou
2023-05-06 3:15 ` [PATCH bpf-next v7 2/2] selftests/bpf: Add testcase for bpf_task_under_cgroup Feng zhou
@ 2023-05-06 21:10 ` patchwork-bot+netdevbpf
2 siblings, 0 replies; 4+ messages in thread
From: patchwork-bot+netdevbpf @ 2023-05-06 21:10 UTC (permalink / raw)
To: Feng zhou
Cc: martin.lau, ast, daniel, andrii, song, yhs, john.fastabend,
kpsingh, sdf, haoluo, jolsa, davem, edumazet, kuba, pabeni,
mykolal, shuah, bpf, linux-kernel, netdev, linux-kselftest,
yangzhenze, wangdongdong.6
Hello:
This series was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <ast@kernel.org>:
On Sat, 6 May 2023 11:15:43 +0800 you wrote:
> From: Feng Zhou <zhoufeng.zf@bytedance.com>
>
> Trace sched related functions, such as enqueue_task_fair, it is necessary to
> specify a task instead of the current task which within a given cgroup.
>
> Feng Zhou (2):
> bpf: Add bpf_task_under_cgroup() kfunc
> selftests/bpf: Add testcase for bpf_task_under_cgroup
>
> [...]
Here is the summary with links:
- [bpf-next,v7,1/2] bpf: Add bpf_task_under_cgroup() kfunc
https://git.kernel.org/bpf/bpf-next/c/b5ad4cdc46c7
- [bpf-next,v7,2/2] selftests/bpf: Add testcase for bpf_task_under_cgroup
https://git.kernel.org/bpf/bpf-next/c/49e0263ab40f
You are awesome, thank you!
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^ permalink raw reply [flat|nested] 4+ messages in thread