diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/task_kfunc_success.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/task_kfunc_success.c | 56 |
1 files changed, 54 insertions, 2 deletions
diff --git a/tools/testing/selftests/bpf/progs/task_kfunc_success.c b/tools/testing/selftests/bpf/progs/task_kfunc_success.c index 70df695312dc..a55149015063 100644 --- a/tools/testing/selftests/bpf/progs/task_kfunc_success.c +++ b/tools/testing/selftests/bpf/progs/task_kfunc_success.c @@ -5,6 +5,7 @@ #include <bpf/bpf_tracing.h> #include <bpf/bpf_helpers.h> +#include "../bpf_experimental.h" #include "task_kfunc_common.h" char _license[] SEC("license") = "GPL"; @@ -142,8 +143,9 @@ int BPF_PROG(test_task_acquire_leave_in_map, struct task_struct *task, u64 clone SEC("tp_btf/task_newtask") int BPF_PROG(test_task_xchg_release, struct task_struct *task, u64 clone_flags) { - struct task_struct *kptr; - struct __tasks_kfunc_map_value *v; + struct task_struct *kptr, *acquired; + struct __tasks_kfunc_map_value *v, *local; + int refcnt, refcnt_after_drop; long status; if (!is_test_kfunc_task()) @@ -167,6 +169,56 @@ int BPF_PROG(test_task_xchg_release, struct task_struct *task, u64 clone_flags) return 0; } + local = bpf_obj_new(typeof(*local)); + if (!local) { + err = 4; + bpf_task_release(kptr); + return 0; + } + + kptr = bpf_kptr_xchg(&local->task, kptr); + if (kptr) { + err = 5; + bpf_obj_drop(local); + bpf_task_release(kptr); + return 0; + } + + kptr = bpf_kptr_xchg(&local->task, NULL); + if (!kptr) { + err = 6; + bpf_obj_drop(local); + return 0; + } + + /* Stash a copy into local kptr and check if it is released recursively */ + acquired = bpf_task_acquire(kptr); + if (!acquired) { + err = 7; + bpf_obj_drop(local); + bpf_task_release(kptr); + return 0; + } + bpf_probe_read_kernel(&refcnt, sizeof(refcnt), &acquired->rcu_users); + + acquired = bpf_kptr_xchg(&local->task, acquired); + if (acquired) { + err = 8; + bpf_obj_drop(local); + bpf_task_release(kptr); + bpf_task_release(acquired); + return 0; + } + + bpf_obj_drop(local); + + bpf_probe_read_kernel(&refcnt_after_drop, sizeof(refcnt_after_drop), &kptr->rcu_users); + if (refcnt != refcnt_after_drop + 1) { + err = 9; + bpf_task_release(kptr); + return 0; + } + bpf_task_release(kptr); return 0; |