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link: expose syscall wrapper symbol helper #2033

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link: expose syscall wrapper symbol helper #2033

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10 changes: 10 additions & 0 deletions link/kprobe.go
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Original file line number Diff line number Diff line change
Expand Up @@ -50,6 +50,16 @@ func (ko *KprobeOptions) cookie() uint64 {
return ko.Cookie
}

// SyscallWrapper returns the platform-specific kernel wrapper symbol for syscall.
func SyscallWrapper(syscall string) string {
prefix := linux.PlatformPrefix()
if prefix == "" || strings.HasPrefix(syscall, prefix) {
return syscall
}

return prefix + syscall
}

// Kprobe attaches the given eBPF program to a perf event that fires when the
// given kernel symbol starts executing. See /proc/kallsyms for available
// symbols. For example, printk():
Expand Down
4 changes: 1 addition & 3 deletions link/kprobe_multi_test.go
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Expand Up @@ -11,7 +11,6 @@ import (

"github.com/cilium/ebpf"
"github.com/cilium/ebpf/features"
"github.com/cilium/ebpf/internal/linux"
"github.com/cilium/ebpf/internal/testutils"
"github.com/cilium/ebpf/internal/unix"
)
Expand Down Expand Up @@ -127,9 +126,8 @@ func TestKprobeMultiProgramCall(t *testing.T) {

// Use actual syscall names with platform prefix.
// For simplicity, just assert the increment happens with any symbol in the array.
prefix := linux.PlatformPrefix()
opts := KprobeMultiOptions{
Symbols: []string{prefix + "sys_getpid", prefix + "sys_gettid"},
Symbols: []string{SyscallWrapper("sys_getpid"), SyscallWrapper("sys_gettid")},
}
km, err := KprobeMulti(p, opts)
if err != nil {
Expand Down
12 changes: 12 additions & 0 deletions link/kprobe_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,7 @@ import (

"github.com/cilium/ebpf"
"github.com/cilium/ebpf/asm"
"github.com/cilium/ebpf/internal/linux"
"github.com/cilium/ebpf/internal/testutils"
"github.com/cilium/ebpf/internal/tracefs"
"github.com/cilium/ebpf/internal/unix"
Expand All @@ -27,6 +28,17 @@ var symTests = []string{
"unregister_kprobes.part.0", // function body that was split and partially inlined
}

func TestSyscallWrapper(t *testing.T) {

@ti-mo ti-mo Jun 9, 2026

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This is basically a copy of the helper logic itself, that makes this test a little unnecessary. It's already being exercised in TestKprobeMultiProgramCall, that's fine.

prefix := linux.PlatformPrefix()

qt.Assert(t, qt.Equals(SyscallWrapper("sys_getpid"), prefix+"sys_getpid"))

if prefix != "" {
wrapped := prefix + "sys_getpid"
qt.Assert(t, qt.Equals(SyscallWrapper(wrapped), wrapped))
}
}

func TestKprobe(t *testing.T) {
prog := mustLoadProgram(t, ebpf.Kprobe, 0, "")

Expand Down
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