bpf: mark bpf_task_work_* kfuncs with KF_IMPLICIT_PROG_AUX_ARG

Two kfuncs that use aux__prog argument were recently added [1]:
  * bpf_task_work_schedule_resume
  * bpf_task_work_schedule_signal

Update them to use the new kfunc flag and fix usages in the selftests.

[1] https://lore.kernel.org/bpf/[email protected]/

Signed-off-by: Ihor Solodrai <[email protected]>

Author: theihor

kernel/bpf/helpers.c

@@ -4178,15 +4178,15 @@ static int bpf_task_work_schedule(struct task_struct *task, struct bpf_task_work
  * @tw: Pointer to struct bpf_task_work in BPF map value for internal bookkeeping
  * @map__map: bpf_map that embeds struct bpf_task_work in the values
  * @callback: pointer to BPF subprogram to call
- * @aux__prog: user should pass NULL
+ * @aux: pointer to bpf_prog_aux of the caller BPF program, implicitly set by the verifier
  *
  * Return: 0 if task work has been scheduled successfully, negative error code otherwise
  */
 __bpf_kfunc int bpf_task_work_schedule_signal(struct task_struct *task, struct bpf_task_work *tw,
 					      void *map__map, bpf_task_work_callback_t callback,
-					      void *aux__prog)
+					      struct bpf_prog_aux *aux)
 {
-	return bpf_task_work_schedule(task, tw, map__map, callback, aux__prog, TWA_SIGNAL);
+	return bpf_task_work_schedule(task, tw, map__map, callback, aux, TWA_SIGNAL);
 }
 
 /**
@@ -4195,15 +4195,15 @@ __bpf_kfunc int bpf_task_work_schedule_signal(struct task_struct *task, struct b
  * @tw: Pointer to struct bpf_task_work in BPF map value for internal bookkeeping
  * @map__map: bpf_map that embeds struct bpf_task_work in the values
  * @callback: pointer to BPF subprogram to call
- * @aux__prog: user should pass NULL
+ * @aux: pointer to bpf_prog_aux of the caller BPF program, implicitly set by the verifier
  *
  * Return: 0 if task work has been scheduled successfully, negative error code otherwise
  */
 __bpf_kfunc int bpf_task_work_schedule_resume(struct task_struct *task, struct bpf_task_work *tw,
 					      void *map__map, bpf_task_work_callback_t callback,
-					      void *aux__prog)
+					      struct bpf_prog_aux *aux)
 {
-	return bpf_task_work_schedule(task, tw, map__map, callback, aux__prog, TWA_RESUME);
+	return bpf_task_work_schedule(task, tw, map__map, callback, aux, TWA_RESUME);
 }
 
 __bpf_kfunc_end_defs();
@@ -4379,8 +4379,8 @@ BTF_ID_FLAGS(func, bpf_strnstr);
 BTF_ID_FLAGS(func, bpf_cgroup_read_xattr, KF_RCU)
 #endif
 BTF_ID_FLAGS(func, bpf_stream_vprintk, KF_TRUSTED_ARGS | KF_IMPLICIT_PROG_AUX_ARG)
-BTF_ID_FLAGS(func, bpf_task_work_schedule_signal, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_task_work_schedule_resume, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_task_work_schedule_signal, KF_TRUSTED_ARGS | KF_IMPLICIT_PROG_AUX_ARG)
+BTF_ID_FLAGS(func, bpf_task_work_schedule_resume, KF_TRUSTED_ARGS | KF_IMPLICIT_PROG_AUX_ARG)
 BTF_ID_FLAGS(func, bpf_wq_set_callback, KF_IMPLICIT_PROG_AUX_ARG)
 BTF_KFUNCS_END(common_btf_ids)
 

tools/testing/selftests/bpf/progs/task_work.c

@@ -66,7 +66,7 @@ int oncpu_hash_map(struct pt_regs *args)
 	if (!work)
 		return 0;
 
-	bpf_task_work_schedule_resume(task, &work->tw, &hmap, process_work, NULL);
+	bpf_task_work_schedule_resume(task, &work->tw, &hmap, process_work);
 	return 0;
 }
 
@@ -80,7 +80,7 @@ int oncpu_array_map(struct pt_regs *args)
 	work = bpf_map_lookup_elem(&arrmap, &key);
 	if (!work)
 		return 0;
-	bpf_task_work_schedule_signal(task, &work->tw, &arrmap, process_work, NULL);
+	bpf_task_work_schedule_signal(task, &work->tw, &arrmap, process_work);
 	return 0;
 }
 
@@ -102,6 +102,6 @@ int oncpu_lru_map(struct pt_regs *args)
 	work = bpf_map_lookup_elem(&lrumap, &key);
 	if (!work || work->data[0])
 		return 0;
-	bpf_task_work_schedule_resume(task, &work->tw, &lrumap, process_work, NULL);
+	bpf_task_work_schedule_resume(task, &work->tw, &lrumap, process_work);
 	return 0;
 }

tools/testing/selftests/bpf/progs/task_work_fail.c

@@ -53,7 +53,7 @@ int mismatch_map(struct pt_regs *args)
 	work = bpf_map_lookup_elem(&arrmap, &key);
 	if (!work)
 		return 0;
-	bpf_task_work_schedule_resume(task, &work->tw, &hmap, process_work, NULL);
+	bpf_task_work_schedule_resume(task, &work->tw, &hmap, process_work);
 	return 0;
 }
 
@@ -65,7 +65,7 @@ int no_map_task_work(struct pt_regs *args)
 	struct bpf_task_work tw;
 
 	task = bpf_get_current_task_btf();
-	bpf_task_work_schedule_resume(task, &tw, &hmap, process_work, NULL);
+	bpf_task_work_schedule_resume(task, &tw, &hmap, process_work);
 	return 0;
 }
 
@@ -76,7 +76,7 @@ int task_work_null(struct pt_regs *args)
 	struct task_struct *task;
 
 	task = bpf_get_current_task_btf();
-	bpf_task_work_schedule_resume(task, NULL, &hmap, process_work, NULL);
+	bpf_task_work_schedule_resume(task, NULL, &hmap, process_work);
 	return 0;
 }
 
@@ -91,6 +91,6 @@ int map_null(struct pt_regs *args)
 	work = bpf_map_lookup_elem(&arrmap, &key);
 	if (!work)
 		return 0;
-	bpf_task_work_schedule_resume(task, &work->tw, NULL, process_work, NULL);
+	bpf_task_work_schedule_resume(task, &work->tw, NULL, process_work);
 	return 0;
 }

tools/testing/selftests/bpf/progs/task_work_stress.c

@@ -52,7 +52,7 @@ int schedule_task_work(void *ctx)
 			return 0;
 	}
 	err = bpf_task_work_schedule_signal(bpf_get_current_task_btf(), &work->tw, &hmap,
-					    process_work, NULL);
+					    process_work);
 	if (err)
 		__sync_fetch_and_add(&schedule_error, 1);
 	else