linux-stable/samples/bpf/tracex6_kern.c
Daniel T. Lee 59929cd1fe samples, bpf: Refactor kprobe, tail call kern progs map definition
Because the previous two commit replaced the bpf_load implementation of
the user program with libbpf, the corresponding kernel program's MAP
definition can be replaced with new BTF-defined map syntax.

This commit only updates the samples which uses libbpf API for loading
bpf program not with bpf_load.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200516040608.1377876-6-danieltimlee@gmail.com
2020-05-19 17:13:03 +02:00

69 lines
1.4 KiB
C

#include <linux/ptrace.h>
#include <linux/version.h>
#include <uapi/linux/bpf.h>
#include <bpf/bpf_helpers.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;
}
SEC("kprobe/htab_map_lookup_elem")
int bpf_prog2(struct pt_regs *ctx)
{
u32 key = bpf_get_smp_processor_id();
struct bpf_perf_event_value *val, buf;
int error;
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;