Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

tetragon: Use cilium/ebpf detection #1904

Merged
merged 3 commits into from
Jan 8, 2024
Merged

tetragon: Use cilium/ebpf detection #1904

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
a2eed2d
tetragon: Use ebpf/cilium feature test for bpf_override_return helper
olsajiri Dec 19, 2023
8447672
tetragon: Use ebpf/cilium feature test for bpf_send_signal
olsajiri Dec 19, 2023
c0aa2c9
tetragon: Use ebpf/cilium feature test for large instructions
olsajiri Dec 19, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
82 changes: 7 additions & 75 deletions pkg/bpf/detect.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@ import (

"github.com/cilium/ebpf"
"github.com/cilium/ebpf/asm"
"github.com/cilium/ebpf/features"
"github.com/cilium/ebpf/link"
"golang.org/x/sys/unix"
)
Expand All @@ -23,62 +24,17 @@ type Feature struct {
}

var (
overrideHelper Feature
signalHelper Feature
kprobeMulti Feature
buildid Feature
modifyReturn Feature
largeProgramSize Feature
kprobeMulti Feature
buildid Feature
modifyReturn Feature
)

func detectOverrideHelper() bool {
prog, err := ebpf.NewProgram(&ebpf.ProgramSpec{
Type: ebpf.Kprobe,
Instructions: asm.Instructions{
asm.LoadImm(asm.R2, 2, asm.DWord),
asm.Instruction{OpCode: asm.OpCode(asm.JumpClass).SetJumpOp(asm.Call), Constant: 58},
asm.LoadImm(asm.R0, 0, asm.DWord),
asm.Return(),
},
License: "GPL",
})
if err != nil {
return false
}
prog.Close()
return true
}

func HasOverrideHelper() bool {
overrideHelper.init.Do(func() {
overrideHelper.detected = detectOverrideHelper()
})
return overrideHelper.detected
}

func detectSignalHelper() bool {
prog, err := ebpf.NewProgram(&ebpf.ProgramSpec{
Type: ebpf.Kprobe,
Instructions: asm.Instructions{
asm.LoadImm(asm.R2, 2, asm.DWord),
asm.Instruction{OpCode: asm.OpCode(asm.JumpClass).SetJumpOp(asm.Call), Constant: 109},
asm.LoadImm(asm.R0, 0, asm.DWord),
asm.Return(),
},
License: "GPL",
})
if err != nil {
return false
}
prog.Close()
return true
return features.HaveProgramHelper(ebpf.Kprobe, asm.FnOverrideReturn) == nil
}

func HasSignalHelper() bool {
signalHelper.init.Do(func() {
signalHelper.detected = detectSignalHelper()
})
return signalHelper.detected
return features.HaveProgramHelper(ebpf.Kprobe, asm.FnSendSignal) == nil
}

func detectKprobeMulti() bool {
Expand Down Expand Up @@ -170,32 +126,8 @@ func HasModifyReturn() bool {
return modifyReturn.detected
}

func detectLargeProgramSize() bool {
insns := asm.Instructions{}

for i := 0; i < 4096; i++ {
insns = append(insns, asm.Mov.Imm(asm.R0, 1))
}
insns = append(insns, asm.Return())

prog, err := ebpf.NewProgram(&ebpf.ProgramSpec{
Type: ebpf.Kprobe,
Instructions: insns,
AttachType: ebpf.AttachModifyReturn,
License: "MIT",
})
if err != nil {
return false
}
prog.Close()
return true
}

func HasProgramLargeSize() bool {
largeProgramSize.init.Do(func() {
largeProgramSize.detected = detectLargeProgramSize()
})
return largeProgramSize.detected
return features.HaveLargeInstructions() == nil
}

func LogFeatures() string {
Expand Down
Loading