From 34f286d38d1329e8f904bbb63c4cfea2f7fe7642 Mon Sep 17 00:00:00 2001
From: Paul Buetow <paul@buetow.org>
Date: Tue, 10 Mar 2026 07:42:04 +0200
Subject: integrationtests: return errors for pidfd syscall lookup (task 377)

---
 integrationtests/cmd/ioworkload/scenario_pidfd.go  | 46 +++++++++++------
 .../cmd/ioworkload/scenario_pidfd_test.go          | 57 ++++++++++++++++++++++
 2 files changed, 87 insertions(+), 16 deletions(-)
 create mode 100644 integrationtests/cmd/ioworkload/scenario_pidfd_test.go

diff --git a/integrationtests/cmd/ioworkload/scenario_pidfd.go b/integrationtests/cmd/ioworkload/scenario_pidfd.go
index 1ac7c4d..2aafced 100644
--- a/integrationtests/cmd/ioworkload/scenario_pidfd.go
+++ b/integrationtests/cmd/ioworkload/scenario_pidfd.go
@@ -76,7 +76,11 @@ func pidfdGetfdFailure() error {
 }
 
 func pidfdOpen(pid int, flags uintptr) (int, error) {
-	fd, _, errno := syscall.Syscall(pidfdOpenSyscallNr(), uintptr(pid), flags, 0)
+	syscallNr, err := pidfdOpenSyscallNr()
+	if err != nil {
+		return 0, err
+	}
+	fd, _, errno := syscall.Syscall(syscallNr, uintptr(pid), flags, 0)
 	if errno != 0 {
 		return 0, errno
 	}
@@ -84,8 +88,12 @@ func pidfdOpen(pid int, flags uintptr) (int, error) {
 }
 
 func pidfdGetfd(pidfd int, targetFd int, flags uintptr) (int, error) {
+	syscallNr, err := pidfdGetfdSyscallNr()
+	if err != nil {
+		return 0, err
+	}
 	fd, _, errno := syscall.Syscall(
-		pidfdGetfdSyscallNr(),
+		syscallNr,
 		uintptr(pidfd),
 		uintptr(targetFd),
 		flags,
@@ -96,24 +104,30 @@ func pidfdGetfd(pidfd int, targetFd int, flags uintptr) (int, error) {
 	return int(fd), nil
 }
 
-func pidfdOpenSyscallNr() uintptr {
+func pidfdOpenSyscallNr() (uintptr, error) {
+	return pidfdOpenSyscallNrForArch(runtime.GOARCH)
+}
+
+func pidfdGetfdSyscallNr() (uintptr, error) {
+	return pidfdGetfdSyscallNrForArch(runtime.GOARCH)
+}
+
+func pidfdOpenSyscallNrForArch(arch string) (uintptr, error) {
 	// Go's syscall package does not expose pidfd constants on all toolchains.
-	if runtime.GOARCH == "amd64" {
-		return 434
+	switch arch {
+	case "amd64", "arm64":
+		return 434, nil
+	default:
+		return 0, fmt.Errorf("pidfd_open syscall number not defined for GOARCH=%s", arch)
 	}
-	if runtime.GOARCH == "arm64" {
-		return 434
-	}
-	panic("pidfd_open syscall number not defined for GOARCH=" + runtime.GOARCH)
 }
 
-func pidfdGetfdSyscallNr() uintptr {
+func pidfdGetfdSyscallNrForArch(arch string) (uintptr, error) {
 	// Go's syscall package does not expose pidfd constants on all toolchains.
-	if runtime.GOARCH == "amd64" {
-		return 438
-	}
-	if runtime.GOARCH == "arm64" {
-		return 438
+	switch arch {
+	case "amd64", "arm64":
+		return 438, nil
+	default:
+		return 0, fmt.Errorf("pidfd_getfd syscall number not defined for GOARCH=%s", arch)
 	}
-	panic("pidfd_getfd syscall number not defined for GOARCH=" + runtime.GOARCH)
 }
diff --git a/integrationtests/cmd/ioworkload/scenario_pidfd_test.go b/integrationtests/cmd/ioworkload/scenario_pidfd_test.go
new file mode 100644
index 0000000..5ee1002
--- /dev/null
+++ b/integrationtests/cmd/ioworkload/scenario_pidfd_test.go
@@ -0,0 +1,57 @@
+package main
+
+import "testing"
+
+func TestPidfdOpenSyscallNrForArch(t *testing.T) {
+	for _, tc := range []struct {
+		name    string
+		arch    string
+		want    uintptr
+		wantErr bool
+	}{
+		{name: "amd64", arch: "amd64", want: 434},
+		{name: "arm64", arch: "arm64", want: 434},
+		{name: "unsupported", arch: "riscv64", wantErr: true},
+	} {
+		got, err := pidfdOpenSyscallNrForArch(tc.arch)
+		if tc.wantErr {
+			if err == nil {
+				t.Fatalf("%s: expected error", tc.name)
+			}
+			continue
+		}
+		if err != nil {
+			t.Fatalf("%s: unexpected error: %v", tc.name, err)
+		}
+		if got != tc.want {
+			t.Fatalf("%s: got %d, want %d", tc.name, got, tc.want)
+		}
+	}
+}
+
+func TestPidfdGetfdSyscallNrForArch(t *testing.T) {
+	for _, tc := range []struct {
+		name    string
+		arch    string
+		want    uintptr
+		wantErr bool
+	}{
+		{name: "amd64", arch: "amd64", want: 438},
+		{name: "arm64", arch: "arm64", want: 438},
+		{name: "unsupported", arch: "riscv64", wantErr: true},
+	} {
+		got, err := pidfdGetfdSyscallNrForArch(tc.arch)
+		if tc.wantErr {
+			if err == nil {
+				t.Fatalf("%s: expected error", tc.name)
+			}
+			continue
+		}
+		if err != nil {
+			t.Fatalf("%s: unexpected error: %v", tc.name, err)
+		}
+		if got != tc.want {
+			t.Fatalf("%s: got %d, want %d", tc.name, got, tc.want)
+		}
+	}
+}
-- 
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