mirror of
				https://github.com/torvalds/linux.git
				synced 2025-11-04 02:30:34 +02:00 
			
		
		
		
	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
		
	
			
		
			
				
	
	
		
			31 lines
		
	
	
	
		
			660 B
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			31 lines
		
	
	
	
		
			660 B
		
	
	
	
		
			C
		
	
	
	
	
	
#include <linux/ptrace.h>
 | 
						|
#include <linux/version.h>
 | 
						|
#include <uapi/linux/bpf.h>
 | 
						|
#include <bpf/bpf_helpers.h>
 | 
						|
#include "trace_common.h"
 | 
						|
 | 
						|
struct {
 | 
						|
	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
 | 
						|
	__uint(key_size, sizeof(int));
 | 
						|
	__uint(value_size, sizeof(u32));
 | 
						|
	__uint(max_entries, 2);
 | 
						|
} my_map SEC(".maps");
 | 
						|
 | 
						|
SEC("kprobe/" SYSCALL(sys_write))
 | 
						|
int bpf_prog1(struct pt_regs *ctx)
 | 
						|
{
 | 
						|
	struct S {
 | 
						|
		u64 pid;
 | 
						|
		u64 cookie;
 | 
						|
	} data;
 | 
						|
 | 
						|
	data.pid = bpf_get_current_pid_tgid();
 | 
						|
	data.cookie = 0x12345678;
 | 
						|
 | 
						|
	bpf_perf_event_output(ctx, &my_map, 0, &data, sizeof(data));
 | 
						|
 | 
						|
	return 0;
 | 
						|
}
 | 
						|
 | 
						|
char _license[] SEC("license") = "GPL";
 | 
						|
u32 _version SEC("version") = LINUX_VERSION_CODE;
 |