Files
gasm-sdk/debug/ptrace_integration_freebsd_test.go
T
2026-09-26 11:08:43 +02:00

92 lines
2.6 KiB
Go

// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
// SPDX-License-Identifier: BSD-3-Clause
//go:build freebsd && amd64
package debug
import (
"os/exec"
"path/filepath"
"runtime"
"testing"
"sourcedock.dev/petrbalvin/gasm-sdk/verify"
)
// TestLaunchAndBreakpoint is the FreeBSD twin of the Linux integration
// test: it drives the whole launch, breakpoint, trap and register-rewind
// flow end to end. It needs a real FreeBSD kernel (ptrace does not work
// under emulation), so it only runs where it can.
func TestLaunchAndBreakpoint(t *testing.T) {
if runtime.GOARCH != "amd64" {
t.Skip("runs only on amd64 hosts")
}
// The tracer is the OS thread that forked the debuggee (PT_TRACE_ME
// binds the relation to that thread); every ptrace request must come
// from the same thread, so pin the test goroutine to one thread.
runtime.LockOSThread()
defer runtime.UnlockOSThread()
bin := filepath.Join(t.TempDir(), "gasm")
out, err := exec.Command("go", "build", "-o", bin, "sourcedock.dev/petrbalvin/gasm-sdk/cmd/gasm").CombinedOutput()
if err != nil {
t.Fatalf("build gasm: %v: %s", err, out)
}
const kernelPath = "../testdata/verify/basic_amd64.s"
k, err := verify.Load(kernelPath)
if err != nil {
t.Fatalf("Load: %v", err)
}
t.Cleanup(k.Close)
fl, err := k.Func("wideCopy")
if err != nil {
t.Fatalf("Func: %v", err)
}
sess, err := Launch(bin, kernelPath, "wideCopy", make([]byte, fl.Args))
if err != nil {
t.Fatalf("Launch: %v", err)
}
t.Cleanup(sess.Kill)
bm := NewBreakpoints(sess)
entry := sess.CodeBase() + uint64(fl.Offset)
if _, err := bm.Set(entry, "entry"); err != nil {
t.Fatalf("Set: %v", err)
}
// The INT3 must be visible in the debuggee's memory.
word, err := sess.Peek(entry)
if err != nil {
t.Fatalf("Peek: %v", err)
}
if b := word & 0xFF; b != 0xCC {
t.Fatalf("int3 not patched: first byte %#02x at %#x", b, entry)
}
// The debuggee raises a second SIGSTOP after the launch barrier (the
// child's RunTarget marks its entry), so like the REPL and the cover
// mode the test keeps resuming until the breakpoint trap arrives.
for range 10 {
if err := sess.Continue(); err != nil {
t.Fatalf("Continue: %v", err)
}
if sess.Exited() {
t.Fatal("debuggee exited instead of trapping on the breakpoint")
}
regs, err := sess.GetRegs()
if err != nil {
t.Fatalf("GetRegs: %v", err)
}
if bp := bm.HandleTrap(&regs); bp != nil {
if bp.Addr != entry {
t.Fatalf("trap at %#x, want %#x", bp.Addr, entry)
}
return // trap on the entry breakpoint: the whole flow works
}
}
t.Fatal("no breakpoint trap after 10 resumes")
}