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#include "vmlinux.h"
#include <linux/version.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_core_read.h>
struct {
__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
__uint(key_size, sizeof(int));
__uint(value_size, sizeof(u32));
__uint(max_entries, 64);
} counters SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__type(key, int);
__type(value, u64);
__uint(max_entries, 64);
} values SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__type(key, int);
__type(value, struct bpf_perf_event_value);
__uint(max_entries, 64);
} values2 SEC(".maps");
SEC("kprobe/htab_map_get_next_key")
int bpf_prog1(struct pt_regs *ctx)
{
u32 key = bpf_get_smp_processor_id();
u64 count, *val;
s64 error;
count = bpf_perf_event_read(&counters, key);
error = (s64)count;
if (error <= -2 && error >= -22)
return 0;
val = bpf_map_lookup_elem(&values, &key);
if (val)
*val = count;
else
bpf_map_update_elem(&values, &key, &count, BPF_NOEXIST);
return 0;
}
/*
* Since *_map_lookup_elem can't be expected to trigger bpf programs
* due to potential deadlocks (bpf_disable_instrumentation), this bpf
* program will be attached to bpf_map_copy_value (which is called
* from map_lookup_elem) and will only filter the hashtable type.
*/
SEC("kprobe/bpf_map_copy_value")
int BPF_KPROBE(bpf_prog2, struct bpf_map *map)
{
u32 key = bpf_get_smp_processor_id();
struct bpf_perf_event_value *val, buf;
enum bpf_map_type type;
int error;
type = BPF_CORE_READ(map, map_type);
if (type != BPF_MAP_TYPE_HASH)
return 0;
error = bpf_perf_event_read_value(&counters, key, &buf, sizeof(buf));
if (error)
return 0;
val = bpf_map_lookup_elem(&values2, &key);
if (val)
*val = buf;
else
bpf_map_update_elem(&values2, &key, &buf, BPF_NOEXIST);
return 0;
}
char _license[] SEC("license") = "GPL";
u32 _version SEC("version") = LINUX_VERSION_CODE;
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