* [PATCH bpf-next v4 0/2] Introduce a new kfunc of bpf_task_under_cgroup @ 2023-04-28 7:17 Feng zhou 2023-04-28 7:17 ` [PATCH bpf-next v4 1/2] bpf: Add bpf_task_under_cgroup() kfunc Feng zhou 2023-04-28 7:17 ` [PATCH bpf-next v4 2/2] selftests/bpf: Add testcase for bpf_task_under_cgroup Feng zhou 0 siblings, 2 replies; 6+ messages in thread From: Feng zhou @ 2023-04-28 7:17 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> 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 Changelog: v3->v4: Addressed comments from Yonghong Song - Modify test cases and test other tasks, not the current task. Details in here: https://lore.kernel.org/all/20230427023019.73576-1-zhoufeng.zf@bytedance.com/ v2->v3: Addressed comments from Alexei Starovoitov - Modify the comment information of the function. - Narrow down the testcase's hook point Details in here: https://lore.kernel.org/all/20230421090403.15515-1-zhoufeng.zf@bytedance.com/ v1->v2: Addressed comments from Alexei Starovoitov - Add kfunc instead. Details in here: https://lore.kernel.org/all/20230420072657.80324-1-zhoufeng.zf@bytedance.com/ kernel/bpf/helpers.c | 20 +++++++ tools/testing/selftests/bpf/DENYLIST.s390x | 1 + .../bpf/prog_tests/task_under_cgroup.c | 55 +++++++++++++++++++ .../bpf/progs/test_task_under_cgroup.c | 51 +++++++++++++++++ 4 files changed, 127 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 -- 2.20.1 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH bpf-next v4 1/2] bpf: Add bpf_task_under_cgroup() kfunc 2023-04-28 7:17 [PATCH bpf-next v4 0/2] Introduce a new kfunc of bpf_task_under_cgroup Feng zhou @ 2023-04-28 7:17 ` Feng zhou 2023-04-28 16:24 ` Yonghong Song 2023-04-28 7:17 ` [PATCH bpf-next v4 2/2] selftests/bpf: Add testcase for bpf_task_under_cgroup Feng zhou 1 sibling, 1 reply; 6+ messages in thread From: Feng zhou @ 2023-04-28 7:17 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> --- kernel/bpf/helpers.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index bb6b4637ebf2..453cbd312366 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -2149,6 +2149,25 @@ __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) +{ + if (unlikely(!ancestor || !task)) + return -EINVAL; + + return task_under_cgroup_hierarchy(task, ancestor); +} #endif /* CONFIG_CGROUPS */ /** @@ -2400,6 +2419,7 @@ 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 [flat|nested] 6+ messages in thread
* Re: [PATCH bpf-next v4 1/2] bpf: Add bpf_task_under_cgroup() kfunc 2023-04-28 7:17 ` [PATCH bpf-next v4 1/2] bpf: Add bpf_task_under_cgroup() kfunc Feng zhou @ 2023-04-28 16:24 ` Yonghong Song 0 siblings, 0 replies; 6+ messages in thread From: Yonghong Song @ 2023-04-28 16:24 UTC (permalink / raw) To: Feng zhou, 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 On 4/28/23 12:17 AM, Feng zhou wrote: > 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> ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH bpf-next v4 2/2] selftests/bpf: Add testcase for bpf_task_under_cgroup 2023-04-28 7:17 [PATCH bpf-next v4 0/2] Introduce a new kfunc of bpf_task_under_cgroup Feng zhou 2023-04-28 7:17 ` [PATCH bpf-next v4 1/2] bpf: Add bpf_task_under_cgroup() kfunc Feng zhou @ 2023-04-28 7:17 ` Feng zhou 2023-04-28 16:32 ` Yonghong Song 1 sibling, 1 reply; 6+ messages in thread From: Feng zhou @ 2023-04-28 7:17 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> --- tools/testing/selftests/bpf/DENYLIST.s390x | 1 + .../bpf/prog_tests/task_under_cgroup.c | 55 +++++++++++++++++++ .../bpf/progs/test_task_under_cgroup.c | 51 +++++++++++++++++ 3 files changed, 107 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..5e79dff86dec --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c @@ -0,0 +1,55 @@ +// 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 = -1; + 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); + else if (pid == -1) + printf("Couldn't fork process!\n"); + + wait(NULL); + + test_task_under_cgroup__detach(skel); + + ASSERT_NEQ(skel->bss->remote_pid, skel->rodata->local_pid, + "test task_under_cgroup"); + +cleanup: + if (foo >= 0) + close(foo); + + test_task_under_cgroup__destroy(skel); +} 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..5bcb726d6d0a --- /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 long 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 = NULL; + + 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 (acquired) + bpf_task_release(acquired); + if (cgrp) + bpf_cgroup_release(cgrp); + return 0; +} + +char _license[] SEC("license") = "GPL"; -- 2.20.1 ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH bpf-next v4 2/2] selftests/bpf: Add testcase for bpf_task_under_cgroup 2023-04-28 7:17 ` [PATCH bpf-next v4 2/2] selftests/bpf: Add testcase for bpf_task_under_cgroup Feng zhou @ 2023-04-28 16:32 ` Yonghong Song 2023-05-04 3:23 ` Feng Zhou 0 siblings, 1 reply; 6+ messages in thread From: Yonghong Song @ 2023-04-28 16:32 UTC (permalink / raw) To: Feng zhou, 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 On 4/28/23 12:17 AM, Feng zhou wrote: > 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> Ack with a few nits below. Acked-by: Yonghong Song <yhs@fb.com> > --- > tools/testing/selftests/bpf/DENYLIST.s390x | 1 + > .../bpf/prog_tests/task_under_cgroup.c | 55 +++++++++++++++++++ > .../bpf/progs/test_task_under_cgroup.c | 51 +++++++++++++++++ > 3 files changed, 107 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..5e79dff86dec > --- /dev/null > +++ b/tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c > @@ -0,0 +1,55 @@ > +// 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 = -1; > + 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); > + else if (pid == -1) > + printf("Couldn't fork process!\n"); ASSERT_* is preferred compared to 'printf'. Maybe ASSERT_TRUE(0, "Couldn't 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: > + if (foo >= 0) "if (foo >= 0)" is not needed. 'foo' is guaranteed ">= 0" as this point. > + close(foo); > + > + test_task_under_cgroup__destroy(skel); > +} > 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..5bcb726d6d0a > --- /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 long cgid; cgid cannot be a negative number. So let us do 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 = NULL; "acquired = NULL" is not needed. Just do "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 (acquired) > + bpf_task_release(acquired); > + if (cgrp) > + bpf_cgroup_release(cgrp); > + return 0; > +} > + > +char _license[] SEC("license") = "GPL"; ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Re: [PATCH bpf-next v4 2/2] selftests/bpf: Add testcase for bpf_task_under_cgroup 2023-04-28 16:32 ` Yonghong Song @ 2023-05-04 3:23 ` Feng Zhou 0 siblings, 0 replies; 6+ messages in thread From: Feng Zhou @ 2023-05-04 3:23 UTC (permalink / raw) To: Yonghong Song, 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 在 2023/4/29 00:32, Yonghong Song 写道: > > > On 4/28/23 12:17 AM, Feng zhou wrote: >> 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> > > Ack with a few nits below. > > Acked-by: Yonghong Song <yhs@fb.com> > >> --- >> tools/testing/selftests/bpf/DENYLIST.s390x | 1 + >> .../bpf/prog_tests/task_under_cgroup.c | 55 +++++++++++++++++++ >> .../bpf/progs/test_task_under_cgroup.c | 51 +++++++++++++++++ >> 3 files changed, 107 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..5e79dff86dec >> --- /dev/null >> +++ b/tools/testing/selftests/bpf/prog_tests/task_under_cgroup.c >> @@ -0,0 +1,55 @@ >> +// 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 = -1; >> + 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); >> + else if (pid == -1) >> + printf("Couldn't fork process!\n"); > > ASSERT_* is preferred compared to 'printf'. Maybe ASSERT_TRUE(0, > "Couldn't fork process")? > Will do. >> + >> + wait(NULL); >> + >> + test_task_under_cgroup__detach(skel); >> + >> + ASSERT_NEQ(skel->bss->remote_pid, skel->rodata->local_pid, >> + "test task_under_cgroup"); >> + >> +cleanup: >> + if (foo >= 0) > > "if (foo >= 0)" is not needed. 'foo' is guaranteed ">= 0" as this point. > Yes >> + close(foo); >> + >> + test_task_under_cgroup__destroy(skel); >> +} >> 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..5bcb726d6d0a >> --- /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 long cgid; > > cgid cannot be a negative number. So let us do > const volatile __u64 cgid; > Ok >> +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 = NULL; > > "acquired = NULL" is not needed. Just do "struct task_struct *acquired;". > Ok >> + >> + 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 (acquired) >> + bpf_task_release(acquired); >> + if (cgrp) >> + bpf_cgroup_release(cgrp); >> + return 0; >> +} >> + >> +char _license[] SEC("license") = "GPL"; ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2023-05-04 3:24 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2023-04-28 7:17 [PATCH bpf-next v4 0/2] Introduce a new kfunc of bpf_task_under_cgroup Feng zhou 2023-04-28 7:17 ` [PATCH bpf-next v4 1/2] bpf: Add bpf_task_under_cgroup() kfunc Feng zhou 2023-04-28 16:24 ` Yonghong Song 2023-04-28 7:17 ` [PATCH bpf-next v4 2/2] selftests/bpf: Add testcase for bpf_task_under_cgroup Feng zhou 2023-04-28 16:32 ` Yonghong Song 2023-05-04 3:23 ` Feng Zhou
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®