gotosocial/vendor/github.com/cilium/ebpf/link/tracepoint.go
dependabot[bot] 57dc742c76
[chore]: Bump github.com/KimMachineGun/automemlimit from 0.2.4 to 0.2.5 (#1666)
Bumps [github.com/KimMachineGun/automemlimit](https://github.com/KimMachineGun/automemlimit) from 0.2.4 to 0.2.5.
- [Release notes](https://github.com/KimMachineGun/automemlimit/releases)
- [Commits](https://github.com/KimMachineGun/automemlimit/compare/v0.2.4...v0.2.5)

---
updated-dependencies:
- dependency-name: github.com/KimMachineGun/automemlimit
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
2023-04-03 11:16:17 +02:00

77 lines
2.1 KiB
Go

package link
import (
"fmt"
"github.com/cilium/ebpf"
)
// TracepointOptions defines additional parameters that will be used
// when loading Tracepoints.
type TracepointOptions struct {
// Arbitrary value that can be fetched from an eBPF program
// via `bpf_get_attach_cookie()`.
//
// Needs kernel 5.15+.
Cookie uint64
}
// 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:
//
// tp, err := Tracepoint("syscalls", "sys_enter_fork", prog, nil)
//
// Losing the reference to the resulting Link (tp) will close the Tracepoint
// and prevent further execution of prog. The Link must be Closed during
// program shutdown to avoid leaking system resources.
//
// 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, opts *TracepointOptions) (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 !isValidTraceID(group) || !isValidTraceID(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, perfAllThreads)
if err != nil {
return nil, err
}
var cookie uint64
if opts != nil {
cookie = opts.Cookie
}
pe := &perfEvent{
typ: tracepointEvent,
group: group,
name: name,
tracefsID: tid,
cookie: cookie,
fd: fd,
}
lnk, err := attachPerfEvent(pe, prog)
if err != nil {
pe.Close()
return nil, err
}
return lnk, nil
}