task-47: add KindExec for execve paths

2 files changed, 77 insertions, 0 deletions

diff --git a/cmd/ioworkload/scenario_process.go b/cmd/ioworkload/scenario_process.go
new file mode 100644
index 0000000..c2c5bbd
--- /dev/null
+++ b/cmd/ioworkload/scenario_process.go
@@ -0,0 +1,76 @@
+package main
+
+import (
+	"fmt"
+	"runtime"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+const processExecEmitFor = 2 * time.Second
+
+func processExecLifecycle() error {
+	deadline := time.Now().Add(processExecEmitFor)
+	for time.Now().Before(deadline) {
+		if err := callExecveMissing(); err != nil {
+			return err
+		}
+		if err := callExecveatMissing(); err != nil {
+			return err
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+	return nil
+}
+
+func callExecveMissing() error {
+	filename, err := syscall.BytePtrFromString("/tmp/ior-missing-execve-only")
+	if err != nil {
+		return fmt.Errorf("execve filename: %w", err)
+	}
+	argv := []uintptr{uintptr(unsafe.Pointer(filename)), 0}
+	envp := []uintptr{0}
+	_, _, errno := syscall.RawSyscall(
+		syscall.SYS_EXECVE,
+		uintptr(unsafe.Pointer(filename)),
+		uintptr(unsafe.Pointer(&argv[0])),
+		uintptr(unsafe.Pointer(&envp[0])),
+	)
+	runtime.KeepAlive(filename)
+	runtime.KeepAlive(argv)
+	runtime.KeepAlive(envp)
+	if errno != syscall.ENOENT {
+		return fmt.Errorf("execve errno=%v, want ENOENT", errno)
+	}
+	return nil
+}
+
+func callExecveatMissing() error {
+	filename, err := syscall.BytePtrFromString("ior-missing-execveat-only")
+	if err != nil {
+		return fmt.Errorf("execveat filename: %w", err)
+	}
+	argv := []uintptr{uintptr(unsafe.Pointer(filename)), 0}
+	envp := []uintptr{0}
+	dirfdSigned := int64(unix.AT_FDCWD)
+	dirfd := uintptr(dirfdSigned)
+	_, _, errno := syscall.RawSyscall6(
+		unix.SYS_EXECVEAT,
+		dirfd,
+		uintptr(unsafe.Pointer(filename)),
+		uintptr(unsafe.Pointer(&argv[0])),
+		uintptr(unsafe.Pointer(&envp[0])),
+		0,
+		0,
+	)
+	runtime.KeepAlive(filename)
+	runtime.KeepAlive(argv)
+	runtime.KeepAlive(envp)
+	if errno != syscall.ENOENT {
+		return fmt.Errorf("execveat errno=%v, want ENOENT", errno)
+	}
+	return nil
+}
diff --git a/cmd/ioworkload/scenarios.go b/cmd/ioworkload/scenarios.go
index a1039e0..1ec8e6d 100644
--- a/cmd/ioworkload/scenarios.go
+++ b/cmd/ioworkload/scenarios.go
@@ -38,6 +38,7 @@ var scenarios = map[string]func() error{
 	"mountfs-management":            mountfsManagement,
 	"polling-epoll":                 pollingEpoll,
 	"sleep-syscalls":                sleepSyscalls,
+	"process-exec-lifecycle":        processExecLifecycle,
 	"family-mixed":                  familyMixed,
 	"close-basic":                   closeBasic,
 	"close-range":                   closeRange,