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-rw-r--r--pkg/sentry/platform/ptrace/BUILD2
-rw-r--r--pkg/sentry/platform/ptrace/ptrace_unsafe.go2
-rw-r--r--pkg/sentry/platform/ptrace/subprocess.go150
-rw-r--r--pkg/sentry/platform/ptrace/subprocess_amd64.go16
-rw-r--r--pkg/sentry/platform/ptrace/subprocess_linux.go175
5 files changed, 276 insertions, 69 deletions
diff --git a/pkg/sentry/platform/ptrace/BUILD b/pkg/sentry/platform/ptrace/BUILD
index ceee895dc..debae058b 100644
--- a/pkg/sentry/platform/ptrace/BUILD
+++ b/pkg/sentry/platform/ptrace/BUILD
@@ -19,6 +19,8 @@ go_library(
visibility = ["//:sandbox"],
deps = [
"//pkg/abi/linux",
+ "//pkg/log",
+ "//pkg/seccomp",
"//pkg/sentry/arch",
"//pkg/sentry/platform",
"//pkg/sentry/platform/filemem",
diff --git a/pkg/sentry/platform/ptrace/ptrace_unsafe.go b/pkg/sentry/platform/ptrace/ptrace_unsafe.go
index b55b2795a..46a8bda8e 100644
--- a/pkg/sentry/platform/ptrace/ptrace_unsafe.go
+++ b/pkg/sentry/platform/ptrace/ptrace_unsafe.go
@@ -136,7 +136,7 @@ func (t *thread) clone(initRegs *syscall.PtraceRegs) (*thread, error) {
return nil, syscall.EINVAL
}
rval, err := t.syscallIgnoreInterrupt(
- initRegs,
+ &t.initRegs,
syscall.SYS_CLONE,
arch.SyscallArgument{Value: uintptr(
syscall.CLONE_FILES |
diff --git a/pkg/sentry/platform/ptrace/subprocess.go b/pkg/sentry/platform/ptrace/subprocess.go
index 035ebc332..6d5ad6b71 100644
--- a/pkg/sentry/platform/ptrace/subprocess.go
+++ b/pkg/sentry/platform/ptrace/subprocess.go
@@ -47,6 +47,11 @@ type thread struct {
tgid int32
tid int32
cpu uint32
+
+ // initRegs are the initial registers for the first thread.
+ //
+ // These are used for the register set for system calls.
+ initRegs syscall.PtraceRegs
}
// threadPool is a collection of threads.
@@ -99,11 +104,6 @@ func (tp *threadPool) lookupOrCreate(currentTID int32, newThread func() *thread)
type subprocess struct {
platform.NoAddressSpaceIO
- // initRegs are the initial registers for the first thread.
- //
- // These are used for the register set for system calls.
- initRegs syscall.PtraceRegs
-
// requests is used to signal creation of new threads.
requests chan chan *thread
@@ -142,7 +142,6 @@ func newSubprocess(create func() (*thread, error)) (*subprocess, error) {
// thread, and responding to requests to make additional threads in the
// traced process. The process will be killed and reaped when the
// request channel is closed, which happens in Release below.
- var initRegs syscall.PtraceRegs
errChan := make(chan error)
requests := make(chan chan *thread)
go func() { // S/R-SAFE: Platform-related.
@@ -156,22 +155,12 @@ func newSubprocess(create func() (*thread, error)) (*subprocess, error) {
return
}
- // Grab registers.
- //
- // Note that we adjust the current register RIP value to be
- // just before the current system call executed. This depends
- // on the definition of the stub itself.
- if err := firstThread.getRegs(&initRegs); err != nil {
- panic(fmt.Sprintf("ptrace get regs failed: %v", err))
- }
- initRegs.Rip -= initRegsRipAdjustment
-
// Ready to handle requests.
errChan <- nil
// Wait for requests to create threads.
for r := range requests {
- t, err := firstThread.clone(&initRegs)
+ t, err := firstThread.clone(&firstThread.initRegs)
if err != nil {
// Should not happen: not recoverable.
panic(fmt.Sprintf("error initializing first thread: %v", err))
@@ -183,15 +172,12 @@ func newSubprocess(create func() (*thread, error)) (*subprocess, error) {
// (Hopefully nobody tgkilled it with a signal <
// SIGSTOP before the SIGSTOP was delivered, in which
// case that signal would be delivered before SIGSTOP.)
- if sig := t.wait(); sig != syscall.SIGSTOP {
+ if sig := t.wait(stopped); sig != syscall.SIGSTOP {
panic(fmt.Sprintf("error waiting for new clone: expected SIGSTOP, got %v", sig))
}
- // Detach the thread without suppressing the SIGSTOP,
- // causing it to enter group-stop.
- if _, _, errno := syscall.RawSyscall6(syscall.SYS_PTRACE, syscall.PTRACE_DETACH, uintptr(t.tid), 0, uintptr(syscall.SIGSTOP), 0, 0); errno != 0 {
- panic(fmt.Sprintf("can't detach new clone: %v", errno))
- }
+ // Detach the thread.
+ t.detach()
// Return the thread.
r <- t
@@ -208,7 +194,6 @@ func newSubprocess(create func() (*thread, error)) (*subprocess, error) {
// Ready.
sp := &subprocess{
- initRegs: initRegs,
requests: requests,
sysemuThreads: threadPool{
threads: make(map[int32]*thread),
@@ -277,16 +262,48 @@ func (t *thread) attach() {
// stopped from the SIGSTOP queued by CLONE_PTRACE (see inner loop of
// newSubprocess), so we always expect to see signal-delivery-stop with
// SIGSTOP.
- if sig := t.wait(); sig != syscall.SIGSTOP {
+ if sig := t.wait(stopped); sig != syscall.SIGSTOP {
panic(fmt.Sprintf("wait failed: expected SIGSTOP, got %v", sig))
}
// Initialize options.
t.init()
+
+ // Grab registers.
+ //
+ // Note that we adjust the current register RIP value to be just before
+ // the current system call executed. This depends on the definition of
+ // the stub itself.
+ if err := t.getRegs(&t.initRegs); err != nil {
+ panic(fmt.Sprintf("ptrace get regs failed: %v", err))
+ }
+ t.initRegs.Rip -= initRegsRipAdjustment
}
+// detach detachs from the thread.
+//
+// Because the SIGSTOP is not supressed, the thread will enter group-stop.
+func (t *thread) detach() {
+ if _, _, errno := syscall.RawSyscall6(syscall.SYS_PTRACE, syscall.PTRACE_DETACH, uintptr(t.tid), 0, uintptr(syscall.SIGSTOP), 0, 0); errno != 0 {
+ panic(fmt.Sprintf("can't detach new clone: %v", errno))
+ }
+}
+
+// waitOutcome is used for wait below.
+type waitOutcome int
+
+const (
+ // stopped indicates that the process was stopped.
+ stopped waitOutcome = iota
+
+ // killed indicates that the process was killed.
+ killed
+)
+
// wait waits for a stop event.
-func (t *thread) wait() syscall.Signal {
+//
+// Precondition: outcome is a valid waitOutcome.
+func (t *thread) wait(outcome waitOutcome) syscall.Signal {
var status syscall.WaitStatus
for {
@@ -300,25 +317,55 @@ func (t *thread) wait() syscall.Signal {
if int(r) != int(t.tid) {
panic(fmt.Sprintf("ptrace wait returned %v, expected %v", r, t.tid))
}
- if !status.Stopped() {
- panic(fmt.Sprintf("ptrace status unexpected: got %v, wanted stopped", status))
- }
- if status.StopSignal() == 0 {
- continue // Spurious stop.
+ switch outcome {
+ case stopped:
+ if !status.Stopped() {
+ panic(fmt.Sprintf("ptrace status unexpected: got %v, wanted stopped", status))
+ }
+ stopSig := status.StopSignal()
+ if stopSig == 0 {
+ continue // Spurious stop.
+ }
+ if stopSig == syscall.SIGTRAP {
+ // Re-encode the trap cause the way it's expected.
+ return stopSig | syscall.Signal(status.TrapCause()<<8)
+ }
+ // Not a trap signal.
+ return stopSig
+ case killed:
+ if !status.Exited() && !status.Signaled() {
+ panic(fmt.Sprintf("ptrace status unexpected: got %v, wanted exited", status))
+ }
+ return syscall.Signal(status.ExitStatus())
+ default:
+ // Should not happen.
+ panic(fmt.Sprintf("unknown outcome: %v", outcome))
}
- return status.StopSignal()
}
}
+// destroy kills the thread.
+//
+// Note that this should not be used in the general case; the death of threads
+// will typically cause the death of the parent. This is a utility method for
+// manually created threads.
+func (t *thread) destroy() {
+ t.detach()
+ syscall.Tgkill(int(t.tgid), int(t.tid), syscall.Signal(syscall.SIGKILL))
+ t.wait(killed)
+}
+
// init initializes trace options.
func (t *thread) init() {
- // Set our TRACESYSGOOD option to differeniate real SIGTRAP.
+ // Set our TRACESYSGOOD option to differeniate real SIGTRAP. Also, we
+ // require the SECCOMP option to ensure that seccomp violations
+ // generate a ptrace event.
_, _, errno := syscall.RawSyscall6(
syscall.SYS_PTRACE,
syscall.PTRACE_SETOPTIONS,
uintptr(t.tid),
0,
- syscall.PTRACE_O_TRACESYSGOOD,
+ syscall.PTRACE_O_TRACESYSGOOD|_PTRACE_O_TRACESECCOMP,
0, 0)
if errno != 0 {
panic(fmt.Sprintf("ptrace set options failed: %v", errno))
@@ -342,8 +389,8 @@ func (t *thread) syscall(regs *syscall.PtraceRegs) (uintptr, error) {
panic(fmt.Sprintf("ptrace syscall-enter failed: %v", errno))
}
- sig := t.wait()
- if sig == (0x80 | syscall.SIGTRAP) {
+ sig := t.wait(stopped)
+ if sig == (syscallEvent | syscall.SIGTRAP) {
// Reached syscall-enter-stop.
break
} else {
@@ -360,7 +407,7 @@ func (t *thread) syscall(regs *syscall.PtraceRegs) (uintptr, error) {
// Wait for syscall-exit-stop. "[Signal-delivery-stop] never happens
// between syscall-enter-stop and syscall-exit-stop; it happens *after*
// syscall-exit-stop.)" - ptrace(2), "Syscall-stops"
- if sig := t.wait(); sig != (0x80 | syscall.SIGTRAP) {
+ if sig := t.wait(stopped); sig != (syscallEvent | syscall.SIGTRAP) {
panic(fmt.Sprintf("wait failed: expected SIGTRAP, got %v [%d]", sig, sig))
}
@@ -403,22 +450,23 @@ func (t *thread) NotifyInterrupt() {
//
// This function returns true on a system call, false on a signal.
func (s *subprocess) switchToApp(c *context, ac arch.Context) bool {
- regs := &ac.StateData().Regs
- s.resetSysemuRegs(regs)
+ // Lock the thread for ptrace operations.
+ runtime.LockOSThread()
+ defer runtime.UnlockOSThread()
// Extract floating point state.
fpState := ac.FloatingPointData()
fpLen, _ := ac.FeatureSet().ExtendedStateSize()
useXsave := ac.FeatureSet().UseXsave()
- // Lock the thread for ptrace operations.
- runtime.LockOSThread()
- defer runtime.UnlockOSThread()
-
// Grab our thread from the pool.
currentTID := int32(procid.Current())
t := s.sysemuThreads.lookupOrCreate(currentTID, s.newThread)
+ // Reset necessary registers.
+ regs := &ac.StateData().Regs
+ t.resetSysemuRegs(regs)
+
// Check for interrupts, and ensure that future interrupts will signal t.
if !c.interrupt.Enable(t) {
// Pending interrupt; simulate.
@@ -459,7 +507,7 @@ func (s *subprocess) switchToApp(c *context, ac arch.Context) bool {
}
// Wait for the syscall-enter stop.
- sig := t.wait()
+ sig := t.wait(stopped)
// Refresh all registers.
if err := t.getRegs(regs); err != nil {
@@ -470,13 +518,17 @@ func (s *subprocess) switchToApp(c *context, ac arch.Context) bool {
}
// Is it a system call?
- if sig == (0x80 | syscall.SIGTRAP) {
+ if sig == (syscallEvent | syscall.SIGTRAP) {
// Ensure registers are sane.
updateSyscallRegs(regs)
return true
- }
-
- if sig == syscall.SIGSTOP {
+ } else if sig == (seccompEvent | syscall.SIGTRAP) {
+ // Seccomp is enabled, and caught the system call. This
+ // is an emulated vsyscall call, since those are caught
+ // only by seccomp and explicitly set to trace.
+ updateSyscallRegs(regs)
+ return true
+ } else if sig == syscall.SIGSTOP {
// SIGSTOP was delivered to another thread in the same thread
// group, which initiated another group stop. Just ignore it.
continue
@@ -507,7 +559,7 @@ func (s *subprocess) syscall(sysno uintptr, args ...arch.SyscallArgument) (uintp
currentTID := int32(procid.Current())
t := s.syscallThreads.lookupOrCreate(currentTID, s.newThread)
- return t.syscallIgnoreInterrupt(&s.initRegs, sysno, args...)
+ return t.syscallIgnoreInterrupt(&t.initRegs, sysno, args...)
}
// MapFile implements platform.AddressSpace.MapFile.
diff --git a/pkg/sentry/platform/ptrace/subprocess_amd64.go b/pkg/sentry/platform/ptrace/subprocess_amd64.go
index 8211215df..c38dc1ff8 100644
--- a/pkg/sentry/platform/ptrace/subprocess_amd64.go
+++ b/pkg/sentry/platform/ptrace/subprocess_amd64.go
@@ -43,20 +43,20 @@ const (
// resetSysemuRegs sets up emulation registers.
//
// This should be called prior to calling sysemu.
-func (s *subprocess) resetSysemuRegs(regs *syscall.PtraceRegs) {
- regs.Cs = s.initRegs.Cs
- regs.Ss = s.initRegs.Ss
- regs.Ds = s.initRegs.Ds
- regs.Es = s.initRegs.Es
- regs.Fs = s.initRegs.Fs
- regs.Gs = s.initRegs.Gs
+func (t *thread) resetSysemuRegs(regs *syscall.PtraceRegs) {
+ regs.Cs = t.initRegs.Cs
+ regs.Ss = t.initRegs.Ss
+ regs.Ds = t.initRegs.Ds
+ regs.Es = t.initRegs.Es
+ regs.Fs = t.initRegs.Fs
+ regs.Gs = t.initRegs.Gs
}
// createSyscallRegs sets up syscall registers.
//
// This should be called to generate registers for a system call.
func createSyscallRegs(initRegs *syscall.PtraceRegs, sysno uintptr, args ...arch.SyscallArgument) syscall.PtraceRegs {
- // Copy initial registers (RIP, segments, etc.).
+ // Copy initial registers.
regs := *initRegs
// Set our syscall number.
diff --git a/pkg/sentry/platform/ptrace/subprocess_linux.go b/pkg/sentry/platform/ptrace/subprocess_linux.go
index b212bbdfe..53adadadd 100644
--- a/pkg/sentry/platform/ptrace/subprocess_linux.go
+++ b/pkg/sentry/platform/ptrace/subprocess_linux.go
@@ -21,14 +21,167 @@ import (
"syscall"
"gvisor.googlesource.com/gvisor/pkg/abi/linux"
+ "gvisor.googlesource.com/gvisor/pkg/log"
+ "gvisor.googlesource.com/gvisor/pkg/seccomp"
"gvisor.googlesource.com/gvisor/pkg/sentry/arch"
"gvisor.googlesource.com/gvisor/pkg/sentry/platform/procid"
)
+const (
+ syscallEvent syscall.Signal = 0x80
+ seccompEvent syscall.Signal = 0x700 // 0x7 (PTRACE_SECCOMP_EVENT) << 8
+ _PTRACE_O_TRACESECCOMP = 0x80 // 1 << 0x7 (PTRACE_SECCOMP_EVENT)
+)
+
+// probeSeccomp returns true iff seccomp is run after ptrace notifications,
+// which is generally the case for kernel version >= 4.8. This check is dynamic
+// because kernels have be backported behavior.
+//
+// See createStub for more information.
+//
+// Precondition: the runtime OS thread must be locked.
+func probeSeccomp() bool {
+ // Create a completely new, destroyable process.
+ t, err := attachedThread(0, uint32(linux.SECCOMP_RET_ERRNO))
+ if err != nil {
+ panic(fmt.Sprintf("seccomp probe failed: %v", err))
+ }
+ defer t.destroy()
+
+ // Set registers to the yield system call. This call is not allowed
+ // by the filters specified in the attachThread function.
+ regs := createSyscallRegs(&t.initRegs, syscall.SYS_SCHED_YIELD)
+ if err := t.setRegs(&regs); err != nil {
+ panic(fmt.Sprintf("ptrace set regs failed: %v", err))
+ }
+
+ for {
+ // Attempt an emulation.
+ if _, _, errno := syscall.RawSyscall(syscall.SYS_PTRACE, syscall.PTRACE_SYSEMU, uintptr(t.tid), 0); errno != 0 {
+ panic(fmt.Sprintf("ptrace syscall-enter failed: %v", errno))
+ }
+
+ sig := t.wait(stopped)
+ if sig == (syscallEvent | syscall.SIGTRAP) {
+ // Did the seccomp errno hook already run? This would
+ // indicate that seccomp is first in line and we're
+ // less than 4.8.
+ if err := t.getRegs(&regs); err != nil {
+ panic(fmt.Sprintf("ptrace get-regs failed: %v", err))
+ }
+ if _, err := syscallReturnValue(&regs); err == nil {
+ // The seccomp errno mode ran first, and reset
+ // the error in the registers.
+ return false
+ }
+ // The seccomp hook did not run yet, and therefore it
+ // is safe to use RET_KILL mode for dispatched calls.
+ return true
+ }
+ }
+}
+
// createStub creates a fresh stub processes.
//
// Precondition: the runtime OS thread must be locked.
func createStub() (*thread, error) {
+ // The exact interactions of ptrace and seccomp are complex, and
+ // changed in recent kernel versions. Before commit 93e35efb8de45, the
+ // seccomp check is done before the ptrace emulation check. This means
+ // that any calls not matching this list will trigger the seccomp
+ // default action instead of notifying ptrace.
+ //
+ // After commit 93e35efb8de45, the seccomp check is done after the
+ // ptrace emulation check. This simplifies using SYSEMU, since seccomp
+ // will never run for emulation. Seccomp will only run for injected
+ // system calls, and thus we can use RET_KILL as our violation action.
+ var defaultAction uint32
+ if probeSeccomp() {
+ log.Infof("Latest seccomp behavior found (kernel >= 4.8 likely)")
+ defaultAction = uint32(linux.SECCOMP_RET_KILL)
+ } else {
+ // We must rely on SYSEMU behavior; tracing with SYSEMU is broken.
+ log.Infof("Legacy seccomp behavior found (kernel < 4.8 likely)")
+ defaultAction = uint32(linux.SECCOMP_RET_ALLOW)
+ }
+
+ // When creating the new child process, we specify SIGKILL as the
+ // signal to deliver when the child exits. We never expect a subprocess
+ // to exit; they are pooled and reused. This is done to ensure that if
+ // a subprocess is OOM-killed, this process (and all other stubs,
+ // transitively) will be killed as well. It's simply not possible to
+ // safely handle a single stub getting killed: the exact state of
+ // execution is unknown and not recoverable.
+ return attachedThread(uintptr(syscall.SIGKILL)|syscall.CLONE_FILES, defaultAction)
+}
+
+// attachedThread returns a new attached thread.
+//
+// Precondition: the runtime OS thread must be locked.
+func attachedThread(flags uintptr, defaultAction uint32) (*thread, error) {
+ // Create a BPF program that allows only the system calls needed by the
+ // stub and all its children. This is used to create child stubs
+ // (below), so we must include the ability to fork, but otherwise lock
+ // down available calls only to what is needed.
+ rules := []seccomp.RuleSet{
+ // Rules for trapping vsyscall access.
+ seccomp.RuleSet{
+ Rules: seccomp.SyscallRules{
+ syscall.SYS_GETTIMEOFDAY: {},
+ syscall.SYS_TIME: {},
+ 309: {}, // SYS_GETCPU.
+ },
+ Action: uint32(linux.SECCOMP_RET_TRACE),
+ Vsyscall: true,
+ },
+ }
+ if defaultAction != uint32(linux.SECCOMP_RET_ALLOW) {
+ rules = append(rules, seccomp.RuleSet{
+ Rules: seccomp.SyscallRules{
+ syscall.SYS_CLONE: []seccomp.Rule{
+ // Allow creation of new subprocesses (used by the master).
+ {seccomp.AllowValue(syscall.CLONE_FILES | syscall.SIGKILL)},
+ // Allow creation of new threads within a single address space (used by addresss spaces).
+ {seccomp.AllowValue(
+ syscall.CLONE_FILES |
+ syscall.CLONE_FS |
+ syscall.CLONE_SIGHAND |
+ syscall.CLONE_THREAD |
+ syscall.CLONE_PTRACE |
+ syscall.CLONE_VM)},
+ },
+
+ // For the initial process creation.
+ syscall.SYS_WAIT4: {},
+ syscall.SYS_ARCH_PRCTL: []seccomp.Rule{
+ {seccomp.AllowValue(linux.ARCH_SET_CPUID), seccomp.AllowValue(0)},
+ },
+ syscall.SYS_EXIT: {},
+
+ // For the stub prctl dance (all).
+ syscall.SYS_PRCTL: []seccomp.Rule{
+ {seccomp.AllowValue(syscall.PR_SET_PDEATHSIG), seccomp.AllowValue(syscall.SIGKILL)},
+ },
+ syscall.SYS_GETPPID: {},
+
+ // For the stub to stop itself (all).
+ syscall.SYS_GETPID: {},
+ syscall.SYS_KILL: []seccomp.Rule{
+ {seccomp.AllowAny{}, seccomp.AllowValue(syscall.SIGSTOP)},
+ },
+
+ // Injected to support the address space operations.
+ syscall.SYS_MMAP: {},
+ syscall.SYS_MUNMAP: {},
+ },
+ Action: uint32(linux.SECCOMP_RET_ALLOW),
+ })
+ }
+ instrs, err := seccomp.BuildProgram(rules, defaultAction)
+ if err != nil {
+ return nil, err
+ }
+
// Declare all variables up front in order to ensure that there's no
// need for allocations between beforeFork & afterFork.
var (
@@ -43,14 +196,8 @@ func createStub() (*thread, error) {
// Among other things, beforeFork masks all signals.
beforeFork()
- // When creating the new child process, we specify SIGKILL as the
- // signal to deliver when the child exits. We never expect a subprocess
- // to exit; they are pooled and reused. This is done to ensure that if
- // a subprocess is OOM-killed, this process (and all other stubs,
- // transitively) will be killed as well. It's simply not possible to
- // safely handle a single stub getting killed: the exact state of
- // execution is unknown and not recoverable.
- pid, _, errno = syscall.RawSyscall6(syscall.SYS_CLONE, uintptr(syscall.SIGKILL)|syscall.CLONE_FILES, 0, 0, 0, 0, 0)
+ // Do the clone.
+ pid, _, errno = syscall.RawSyscall6(syscall.SYS_CLONE, flags, 0, 0, 0, 0, 0)
if errno != 0 {
afterFork()
return nil, errno
@@ -67,7 +214,7 @@ func createStub() (*thread, error) {
tid: int32(pid),
cpu: ^uint32(0),
}
- if sig := t.wait(); sig != syscall.SIGSTOP {
+ if sig := t.wait(stopped); sig != syscall.SIGSTOP {
return nil, fmt.Errorf("wait failed: expected SIGSTOP, got %v", sig)
}
t.attach()
@@ -86,6 +233,12 @@ func createStub() (*thread, error) {
syscall.RawSyscall(syscall.SYS_EXIT, uintptr(errno), 0, 0)
}
+ // Set an aggressive BPF filter for the stub and all it's children. See
+ // the description of the BPF program built above.
+ if errno := seccomp.SetFilter(instrs); errno != 0 {
+ syscall.RawSyscall(syscall.SYS_EXIT, uintptr(errno), 0, 0)
+ }
+
// Enable cpuid-faulting; this may fail on older kernels or hardware,
// so we just disregard the result. Host CPUID will be enabled.
syscall.RawSyscall(syscall.SYS_ARCH_PRCTL, linux.ARCH_SET_CPUID, 0, 0)
@@ -105,7 +258,7 @@ func (s *subprocess) createStub() (*thread, error) {
t := s.syscallThreads.lookupOrCreate(currentTID, s.newThread)
// Pass the expected PPID to the child via R15.
- regs := s.initRegs
+ regs := t.initRegs
regs.R15 = uint64(t.tgid)
// Call fork in a subprocess.
@@ -138,7 +291,7 @@ func (s *subprocess) createStub() (*thread, error) {
// status. If the wait succeeds, we'll assume that it was the SIGSTOP.
// If the child actually exited, the attach below will fail.
_, err = t.syscallIgnoreInterrupt(
- &s.initRegs,
+ &t.initRegs,
syscall.SYS_WAIT4,
arch.SyscallArgument{Value: uintptr(pid)},
arch.SyscallArgument{Value: 0},
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-18 13:30:38 +0000