diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/cgrp_ls_sleepable.c')
-rw-r--r-- | tools/testing/selftests/bpf/progs/cgrp_ls_sleepable.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/cgrp_ls_sleepable.c b/tools/testing/selftests/bpf/progs/cgrp_ls_sleepable.c new file mode 100644 index 000000000000..2d11ed528b6f --- /dev/null +++ b/tools/testing/selftests/bpf/progs/cgrp_ls_sleepable.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ + +#include "bpf_iter.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include "bpf_misc.h" + +char _license[] SEC("license") = "GPL"; + +struct { + __uint(type, BPF_MAP_TYPE_CGRP_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC); + __type(key, int); + __type(value, long); +} map_a SEC(".maps"); + +__u32 target_pid; +__u64 cgroup_id; + +void bpf_rcu_read_lock(void) __ksym; +void bpf_rcu_read_unlock(void) __ksym; + +SEC("?iter.s/cgroup") +int cgroup_iter(struct bpf_iter__cgroup *ctx) +{ + struct seq_file *seq = ctx->meta->seq; + struct cgroup *cgrp = ctx->cgroup; + long *ptr; + + if (cgrp == NULL) + return 0; + + ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0, + BPF_LOCAL_STORAGE_GET_F_CREATE); + if (ptr) + cgroup_id = cgrp->kn->id; + return 0; +} + +SEC("?fentry.s/" SYS_PREFIX "sys_getpgid") +int no_rcu_lock(void *ctx) +{ + struct task_struct *task; + struct cgroup *cgrp; + long *ptr; + + task = bpf_get_current_task_btf(); + if (task->pid != target_pid) + return 0; + + /* ptr_to_btf_id semantics. should work. */ + cgrp = task->cgroups->dfl_cgrp; + ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0, + BPF_LOCAL_STORAGE_GET_F_CREATE); + if (ptr) + cgroup_id = cgrp->kn->id; + return 0; +} + +SEC("?fentry.s/" SYS_PREFIX "sys_getpgid") +int yes_rcu_lock(void *ctx) +{ + struct task_struct *task; + struct cgroup *cgrp; + long *ptr; + + task = bpf_get_current_task_btf(); + if (task->pid != target_pid) + return 0; + + bpf_rcu_read_lock(); + cgrp = task->cgroups->dfl_cgrp; + /* cgrp is untrusted and cannot pass to bpf_cgrp_storage_get() helper. */ + ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0, BPF_LOCAL_STORAGE_GET_F_CREATE); + if (ptr) + cgroup_id = cgrp->kn->id; + bpf_rcu_read_unlock(); + return 0; +} |