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// SPDX-License-Identifier: GPL-2.0
#include <vmlinux.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_helpers.h>
struct map_value {
struct prog_test_ref_kfunc __kptr_ref *ptr;
};
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__type(key, int);
__type(value, struct map_value);
__uint(max_entries, 16);
} array_map SEC(".maps");
extern struct prog_test_ref_kfunc *bpf_kfunc_call_test_acquire(unsigned long *sp) __ksym;
extern void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p) __ksym;
static __noinline int cb1(void *map, void *key, void *value, void *ctx)
{
void *p = *(void **)ctx;
bpf_kfunc_call_test_release(p);
/* Without the fix this would cause underflow */
return 0;
}
SEC("?tc")
int underflow_prog(void *ctx)
{
struct prog_test_ref_kfunc *p;
unsigned long sl = 0;
p = bpf_kfunc_call_test_acquire(&sl);
if (!p)
return 0;
bpf_for_each_map_elem(&array_map, cb1, &p, 0);
return 0;
}
static __always_inline int cb2(void *map, void *key, void *value, void *ctx)
{
unsigned long sl = 0;
*(void **)ctx = bpf_kfunc_call_test_acquire(&sl);
/* Without the fix this would leak memory */
return 0;
}
SEC("?tc")
int leak_prog(void *ctx)
{
struct prog_test_ref_kfunc *p;
struct map_value *v;
unsigned long sl;
v = bpf_map_lookup_elem(&array_map, &(int){0});
if (!v)
return 0;
p = NULL;
bpf_for_each_map_elem(&array_map, cb2, &p, 0);
p = bpf_kptr_xchg(&v->ptr, p);
if (p)
bpf_kfunc_call_test_release(p);
return 0;
}
static __always_inline int cb(void *map, void *key, void *value, void *ctx)
{
return 0;
}
static __always_inline int cb3(void *map, void *key, void *value, void *ctx)
{
unsigned long sl = 0;
void *p;
bpf_kfunc_call_test_acquire(&sl);
bpf_for_each_map_elem(&array_map, cb, &p, 0);
/* It should only complain here, not in cb. This is why we need
* callback_ref to be set to frameno.
*/
return 0;
}
SEC("?tc")
int nested_cb(void *ctx)
{
struct prog_test_ref_kfunc *p;
unsigned long sl = 0;
int sp = 0;
p = bpf_kfunc_call_test_acquire(&sl);
if (!p)
return 0;
bpf_for_each_map_elem(&array_map, cb3, &sp, 0);
bpf_kfunc_call_test_release(p);
return 0;
}
SEC("?tc")
int non_cb_transfer_ref(void *ctx)
{
struct prog_test_ref_kfunc *p;
unsigned long sl = 0;
p = bpf_kfunc_call_test_acquire(&sl);
if (!p)
return 0;
cb1(NULL, NULL, NULL, &p);
bpf_kfunc_call_test_acquire(&sl);
return 0;
}
char _license[] SEC("license") = "GPL";
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