k3s/vendor/github.com/cilium/ebpf/link/tracepoint.go
Brad Davidson e204d863a5 Update Kubernetes to v1.22.1
* Update Kubernetes to v1.22.1
* Update dependent modules to track with upstream

Signed-off-by: Brad Davidson <brad.davidson@rancher.com>
2021-08-20 18:47:16 -07:00

57 lines
1.5 KiB
Go

package link
import (
"fmt"
"github.com/cilium/ebpf"
)
// Tracepoint attaches the given eBPF program to the tracepoint with the given
// group and name. See /sys/kernel/debug/tracing/events to find available
// tracepoints. The top-level directory is the group, the event's subdirectory
// is the name. Example:
//
// Tracepoint("syscalls", "sys_enter_fork", prog)
//
// Note that attaching eBPF programs to syscalls (sys_enter_*/sys_exit_*) is
// only possible as of kernel 4.14 (commit cf5f5ce).
func Tracepoint(group, name string, prog *ebpf.Program) (Link, error) {
if group == "" || name == "" {
return nil, fmt.Errorf("group and name cannot be empty: %w", errInvalidInput)
}
if prog == nil {
return nil, fmt.Errorf("prog cannot be nil: %w", errInvalidInput)
}
if !rgxTraceEvent.MatchString(group) || !rgxTraceEvent.MatchString(name) {
return nil, fmt.Errorf("group and name '%s/%s' must be alphanumeric or underscore: %w", group, name, errInvalidInput)
}
if prog.Type() != ebpf.TracePoint {
return nil, fmt.Errorf("eBPF program type %s is not a Tracepoint: %w", prog.Type(), errInvalidInput)
}
tid, err := getTraceEventID(group, name)
if err != nil {
return nil, err
}
fd, err := openTracepointPerfEvent(tid)
if err != nil {
return nil, err
}
pe := &perfEvent{
fd: fd,
tracefsID: tid,
group: group,
name: name,
typ: tracepointEvent,
}
if err := pe.attach(prog); err != nil {
pe.Close()
return nil, err
}
return pe, nil
}