samples: bpf: Refactor kprobe tracing programs with libbpf

For the problem of increasing fragmentation of the bpf loader programs,
instead of using bpf_loader.o, which is used in samples/bpf, this
commit refactors the existing kprobe tracing programs with libbbpf
bpf loader.

    - For kprobe events pointing to system calls, the SYSCALL() macro in
    trace_common.h was used.
    - Adding a kprobe event and attaching a bpf program to it was done
    through bpf_program_attach().
    - Instead of using the existing BPF MAP definition, MAP definition
    has been refactored with the new BTF-defined MAP format.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200823085334.9413-3-danieltimlee@gmail.com

1 files changed, 18 insertions, 18 deletions

diff --git a/samples/bpf/spintest_kern.c b/samples/bpf/spintest_kern.c
index f508af357251..455da77319d9 100644
--- a/samples/bpf/spintest_kern.c
+++ b/samples/bpf/spintest_kern.c
@@ -12,25 +12,25 @@
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>
 
-struct bpf_map_def SEC("maps") my_map = {
-	.type = BPF_MAP_TYPE_HASH,
-	.key_size = sizeof(long),
-	.value_size = sizeof(long),
-	.max_entries = 1024,
-};
-struct bpf_map_def SEC("maps") my_map2 = {
-	.type = BPF_MAP_TYPE_PERCPU_HASH,
-	.key_size = sizeof(long),
-	.value_size = sizeof(long),
-	.max_entries = 1024,
-};
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, long);
+	__type(value, long);
+	__uint(max_entries, 1024);
+} my_map SEC(".maps");
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
+	__uint(key_size, sizeof(long));
+	__uint(value_size, sizeof(long));
+	__uint(max_entries, 1024);
+} my_map2 SEC(".maps");
 
-struct bpf_map_def SEC("maps") stackmap = {
-	.type = BPF_MAP_TYPE_STACK_TRACE,
-	.key_size = sizeof(u32),
-	.value_size = PERF_MAX_STACK_DEPTH * sizeof(u64),
-	.max_entries = 10000,
-};
+struct {
+	__uint(type, BPF_MAP_TYPE_STACK_TRACE);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
+	__uint(max_entries, 10000);
+} stackmap SEC(".maps");
 
 #define PROG(foo) \
 int foo(struct pt_regs *ctx) \