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v6.13.7
  1#include "bpf_experimental.h"
  2
  3struct val_t {
  4	long b, c, d;
  5};
  6
  7struct elem {
  8	long sum;
  9	struct val_t __percpu_kptr *pc;
 10};
 11
 12struct {
 13	__uint(type, BPF_MAP_TYPE_ARRAY);
 14	__uint(max_entries, 1);
 15	__type(key, int);
 16	__type(value, struct elem);
 17} array SEC(".maps");
 18
 19void bpf_rcu_read_lock(void) __ksym;
 20void bpf_rcu_read_unlock(void) __ksym;
 21
 22const volatile int nr_cpus;
 23
 24/* Initialize the percpu object */
 25SEC("?fentry/bpf_fentry_test1")
 26int BPF_PROG(test_array_map_1)
 27{
 28	struct val_t __percpu_kptr *p;
 29	struct elem *e;
 30	int index = 0;
 31
 32	e = bpf_map_lookup_elem(&array, &index);
 33	if (!e)
 34		return 0;
 35
 36	p = bpf_percpu_obj_new(struct val_t);
 37	if (!p)
 38		return 0;
 39
 40	p = bpf_kptr_xchg(&e->pc, p);
 41	if (p)
 42		bpf_percpu_obj_drop(p);
 43
 44	return 0;
 45}
 46
 47/* Update percpu data */
 48SEC("?fentry/bpf_fentry_test2")
 49int BPF_PROG(test_array_map_2)
 50{
 51	struct val_t __percpu_kptr *p;
 52	struct val_t *v;
 53	struct elem *e;
 54	int index = 0;
 55
 56	e = bpf_map_lookup_elem(&array, &index);
 57	if (!e)
 58		return 0;
 59
 60	p = e->pc;
 61	if (!p)
 62		return 0;
 63
 64	v = bpf_per_cpu_ptr(p, 0);
 65	if (!v)
 66		return 0;
 67	v->c = 1;
 68	v->d = 2;
 69
 70	return 0;
 71}
 72
 73int cpu0_field_d, sum_field_c;
 74int my_pid;
 75
 76/* Summarize percpu data */
 77SEC("?fentry/bpf_fentry_test3")
 78int BPF_PROG(test_array_map_3)
 79{
 80	struct val_t __percpu_kptr *p;
 81	int i, index = 0;
 82	struct val_t *v;
 83	struct elem *e;
 84
 85	if ((bpf_get_current_pid_tgid() >> 32) != my_pid)
 86		return 0;
 87
 88	e = bpf_map_lookup_elem(&array, &index);
 89	if (!e)
 90		return 0;
 91
 92	p = e->pc;
 93	if (!p)
 94		return 0;
 95
 96	bpf_for(i, 0, nr_cpus) {
 97		v = bpf_per_cpu_ptr(p, i);
 98		if (v) {
 99			if (i == 0)
100				cpu0_field_d = v->d;
101			sum_field_c += v->c;
102		}
103	}
104
105	return 0;
106}
107
108/* Explicitly free allocated percpu data */
109SEC("?fentry/bpf_fentry_test4")
110int BPF_PROG(test_array_map_4)
111{
112	struct val_t __percpu_kptr *p;
113	struct elem *e;
114	int index = 0;
115
116	e = bpf_map_lookup_elem(&array, &index);
117	if (!e)
118		return 0;
119
120	/* delete */
121	p = bpf_kptr_xchg(&e->pc, NULL);
122	if (p) {
123		bpf_percpu_obj_drop(p);
124	}
125
126	return 0;
127}
128
129SEC("?fentry.s/bpf_fentry_test1")
130int BPF_PROG(test_array_map_10)
131{
132	struct val_t __percpu_kptr *p, *p1;
133	int i, index = 0;
134	struct val_t *v;
135	struct elem *e;
136
137	if ((bpf_get_current_pid_tgid() >> 32) != my_pid)
138		return 0;
139
140	e = bpf_map_lookup_elem(&array, &index);
141	if (!e)
142		return 0;
143
144	bpf_rcu_read_lock();
145	p = e->pc;
146	if (!p) {
147		p = bpf_percpu_obj_new(struct val_t);
148		if (!p)
149			goto out;
150
151		p1 = bpf_kptr_xchg(&e->pc, p);
152		if (p1) {
153			/* race condition */
154			bpf_percpu_obj_drop(p1);
155		}
156	}
157
158	v = bpf_this_cpu_ptr(p);
159	v->c = 3;
160	v = bpf_this_cpu_ptr(p);
161	v->c = 0;
162
163	v = bpf_per_cpu_ptr(p, 0);
164	if (!v)
165		goto out;
166	v->c = 1;
167	v->d = 2;
168
169	/* delete */
170	p1 = bpf_kptr_xchg(&e->pc, NULL);
171	if (!p1)
172		goto out;
173
174	bpf_for(i, 0, nr_cpus) {
175		v = bpf_per_cpu_ptr(p, i);
176		if (v) {
177			if (i == 0)
178				cpu0_field_d = v->d;
179			sum_field_c += v->c;
180		}
181	}
182
183	/* finally release p */
184	bpf_percpu_obj_drop(p1);
185out:
186	bpf_rcu_read_unlock();
187	return 0;
188}
189
190char _license[] SEC("license") = "GPL";
v6.8
  1#include "bpf_experimental.h"
  2
  3struct val_t {
  4	long b, c, d;
  5};
  6
  7struct elem {
  8	long sum;
  9	struct val_t __percpu_kptr *pc;
 10};
 11
 12struct {
 13	__uint(type, BPF_MAP_TYPE_ARRAY);
 14	__uint(max_entries, 1);
 15	__type(key, int);
 16	__type(value, struct elem);
 17} array SEC(".maps");
 18
 19void bpf_rcu_read_lock(void) __ksym;
 20void bpf_rcu_read_unlock(void) __ksym;
 21
 22const volatile int nr_cpus;
 23
 24/* Initialize the percpu object */
 25SEC("?fentry/bpf_fentry_test1")
 26int BPF_PROG(test_array_map_1)
 27{
 28	struct val_t __percpu_kptr *p;
 29	struct elem *e;
 30	int index = 0;
 31
 32	e = bpf_map_lookup_elem(&array, &index);
 33	if (!e)
 34		return 0;
 35
 36	p = bpf_percpu_obj_new(struct val_t);
 37	if (!p)
 38		return 0;
 39
 40	p = bpf_kptr_xchg(&e->pc, p);
 41	if (p)
 42		bpf_percpu_obj_drop(p);
 43
 44	return 0;
 45}
 46
 47/* Update percpu data */
 48SEC("?fentry/bpf_fentry_test2")
 49int BPF_PROG(test_array_map_2)
 50{
 51	struct val_t __percpu_kptr *p;
 52	struct val_t *v;
 53	struct elem *e;
 54	int index = 0;
 55
 56	e = bpf_map_lookup_elem(&array, &index);
 57	if (!e)
 58		return 0;
 59
 60	p = e->pc;
 61	if (!p)
 62		return 0;
 63
 64	v = bpf_per_cpu_ptr(p, 0);
 65	if (!v)
 66		return 0;
 67	v->c = 1;
 68	v->d = 2;
 69
 70	return 0;
 71}
 72
 73int cpu0_field_d, sum_field_c;
 74int my_pid;
 75
 76/* Summarize percpu data */
 77SEC("?fentry/bpf_fentry_test3")
 78int BPF_PROG(test_array_map_3)
 79{
 80	struct val_t __percpu_kptr *p;
 81	int i, index = 0;
 82	struct val_t *v;
 83	struct elem *e;
 84
 85	if ((bpf_get_current_pid_tgid() >> 32) != my_pid)
 86		return 0;
 87
 88	e = bpf_map_lookup_elem(&array, &index);
 89	if (!e)
 90		return 0;
 91
 92	p = e->pc;
 93	if (!p)
 94		return 0;
 95
 96	bpf_for(i, 0, nr_cpus) {
 97		v = bpf_per_cpu_ptr(p, i);
 98		if (v) {
 99			if (i == 0)
100				cpu0_field_d = v->d;
101			sum_field_c += v->c;
102		}
103	}
104
105	return 0;
106}
107
108/* Explicitly free allocated percpu data */
109SEC("?fentry/bpf_fentry_test4")
110int BPF_PROG(test_array_map_4)
111{
112	struct val_t __percpu_kptr *p;
113	struct elem *e;
114	int index = 0;
115
116	e = bpf_map_lookup_elem(&array, &index);
117	if (!e)
118		return 0;
119
120	/* delete */
121	p = bpf_kptr_xchg(&e->pc, NULL);
122	if (p) {
123		bpf_percpu_obj_drop(p);
124	}
125
126	return 0;
127}
128
129SEC("?fentry.s/bpf_fentry_test1")
130int BPF_PROG(test_array_map_10)
131{
132	struct val_t __percpu_kptr *p, *p1;
133	int i, index = 0;
134	struct val_t *v;
135	struct elem *e;
136
137	if ((bpf_get_current_pid_tgid() >> 32) != my_pid)
138		return 0;
139
140	e = bpf_map_lookup_elem(&array, &index);
141	if (!e)
142		return 0;
143
144	bpf_rcu_read_lock();
145	p = e->pc;
146	if (!p) {
147		p = bpf_percpu_obj_new(struct val_t);
148		if (!p)
149			goto out;
150
151		p1 = bpf_kptr_xchg(&e->pc, p);
152		if (p1) {
153			/* race condition */
154			bpf_percpu_obj_drop(p1);
155		}
156	}
157
158	v = bpf_this_cpu_ptr(p);
159	v->c = 3;
160	v = bpf_this_cpu_ptr(p);
161	v->c = 0;
162
163	v = bpf_per_cpu_ptr(p, 0);
164	if (!v)
165		goto out;
166	v->c = 1;
167	v->d = 2;
168
169	/* delete */
170	p1 = bpf_kptr_xchg(&e->pc, NULL);
171	if (!p1)
172		goto out;
173
174	bpf_for(i, 0, nr_cpus) {
175		v = bpf_per_cpu_ptr(p, i);
176		if (v) {
177			if (i == 0)
178				cpu0_field_d = v->d;
179			sum_field_c += v->c;
180		}
181	}
182
183	/* finally release p */
184	bpf_percpu_obj_drop(p1);
185out:
186	bpf_rcu_read_unlock();
187	return 0;
188}
189
190char _license[] SEC("license") = "GPL";