diff options
Diffstat (limited to 'pkg/sentry')
-rw-r--r-- | pkg/sentry/arch/BUILD | 1 | ||||
-rw-r--r-- | pkg/sentry/arch/arch.go | 8 | ||||
-rw-r--r-- | pkg/sentry/arch/signal.go | 22 | ||||
-rw-r--r-- | pkg/sentry/arch/signal_act.go | 83 | ||||
-rw-r--r-- | pkg/sentry/arch/signal_amd64.go | 11 | ||||
-rw-r--r-- | pkg/sentry/arch/signal_arm64.go | 11 | ||||
-rw-r--r-- | pkg/sentry/kernel/signal_handlers.go | 17 | ||||
-rw-r--r-- | pkg/sentry/kernel/task_exit.go | 4 | ||||
-rw-r--r-- | pkg/sentry/kernel/task_signals.go | 51 | ||||
-rw-r--r-- | pkg/sentry/sighandling/sighandling_unsafe.go | 13 | ||||
-rw-r--r-- | pkg/sentry/strace/signal.go | 4 | ||||
-rw-r--r-- | pkg/sentry/syscalls/linux/sys_signal.go | 10 |
12 files changed, 42 insertions, 193 deletions
diff --git a/pkg/sentry/arch/BUILD b/pkg/sentry/arch/BUILD index c9c52530d..d8253ecbe 100644 --- a/pkg/sentry/arch/BUILD +++ b/pkg/sentry/arch/BUILD @@ -15,7 +15,6 @@ go_library( "arch_x86_impl.go", "auxv.go", "signal.go", - "signal_act.go", "signal_amd64.go", "signal_arm64.go", "signal_info.go", diff --git a/pkg/sentry/arch/arch.go b/pkg/sentry/arch/arch.go index 290863ee6..9db228bab 100644 --- a/pkg/sentry/arch/arch.go +++ b/pkg/sentry/arch/arch.go @@ -134,10 +134,6 @@ type Context interface { // RegisterMap returns a map of all registers. RegisterMap() (map[string]uintptr, error) - // NewSignalAct returns a new object that is equivalent to struct sigaction - // in the guest architecture. - NewSignalAct() NativeSignalAct - // NewSignalStack returns a new object that is equivalent to stack_t in the // guest architecture. NewSignalStack() NativeSignalStack @@ -148,7 +144,7 @@ type Context interface { // st is the stack where the signal handler frame should be // constructed. // - // act is the SignalAct that specifies how this signal is being + // act is the SigAction that specifies how this signal is being // handled. // // info is the SignalInfo of the signal being delivered. @@ -157,7 +153,7 @@ type Context interface { // stack is not going to be used). // // sigset is the signal mask before entering the signal handler. - SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt *SignalStack, sigset linux.SignalSet) error + SignalSetup(st *Stack, act *linux.SigAction, info *SignalInfo, alt *SignalStack, sigset linux.SignalSet) error // SignalRestore restores context after returning from a signal // handler. diff --git a/pkg/sentry/arch/signal.go b/pkg/sentry/arch/signal.go index 67d7edf68..3e601b17e 100644 --- a/pkg/sentry/arch/signal.go +++ b/pkg/sentry/arch/signal.go @@ -19,28 +19,6 @@ import ( "gvisor.dev/gvisor/pkg/hostarch" ) -// SignalAct represents the action that should be taken when a signal is -// delivered, and is equivalent to struct sigaction. -// -// +marshal -// +stateify savable -type SignalAct struct { - Handler uint64 - Flags uint64 - Restorer uint64 // Only used on amd64. - Mask linux.SignalSet -} - -// SerializeFrom implements NativeSignalAct.SerializeFrom. -func (s *SignalAct) SerializeFrom(other *SignalAct) { - *s = *other -} - -// DeserializeTo implements NativeSignalAct.DeserializeTo. -func (s *SignalAct) DeserializeTo(other *SignalAct) { - *other = *s -} - // SignalStack represents information about a user stack, and is equivalent to // stack_t. // diff --git a/pkg/sentry/arch/signal_act.go b/pkg/sentry/arch/signal_act.go deleted file mode 100644 index d3e2324a8..000000000 --- a/pkg/sentry/arch/signal_act.go +++ /dev/null @@ -1,83 +0,0 @@ -// Copyright 2018 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -package arch - -import "gvisor.dev/gvisor/pkg/marshal" - -// Special values for SignalAct.Handler. -const ( - // SignalActDefault is SIG_DFL and specifies that the default behavior for - // a signal should be taken. - SignalActDefault = 0 - - // SignalActIgnore is SIG_IGN and specifies that a signal should be - // ignored. - SignalActIgnore = 1 -) - -// Available signal flags. -const ( - SignalFlagNoCldStop = 0x00000001 - SignalFlagNoCldWait = 0x00000002 - SignalFlagSigInfo = 0x00000004 - SignalFlagRestorer = 0x04000000 - SignalFlagOnStack = 0x08000000 - SignalFlagRestart = 0x10000000 - SignalFlagInterrupt = 0x20000000 - SignalFlagNoDefer = 0x40000000 - SignalFlagResetHandler = 0x80000000 -) - -// IsSigInfo returns true iff this handle expects siginfo. -func (s SignalAct) IsSigInfo() bool { - return s.Flags&SignalFlagSigInfo != 0 -} - -// IsNoDefer returns true iff this SignalAct has the NoDefer flag set. -func (s SignalAct) IsNoDefer() bool { - return s.Flags&SignalFlagNoDefer != 0 -} - -// IsRestart returns true iff this SignalAct has the Restart flag set. -func (s SignalAct) IsRestart() bool { - return s.Flags&SignalFlagRestart != 0 -} - -// IsResetHandler returns true iff this SignalAct has the ResetHandler flag set. -func (s SignalAct) IsResetHandler() bool { - return s.Flags&SignalFlagResetHandler != 0 -} - -// IsOnStack returns true iff this SignalAct has the OnStack flag set. -func (s SignalAct) IsOnStack() bool { - return s.Flags&SignalFlagOnStack != 0 -} - -// HasRestorer returns true iff this SignalAct has the Restorer flag set. -func (s SignalAct) HasRestorer() bool { - return s.Flags&SignalFlagRestorer != 0 -} - -// NativeSignalAct is a type that is equivalent to struct sigaction in the -// guest architecture. -type NativeSignalAct interface { - marshal.Marshallable - - // SerializeFrom copies the data in the host SignalAct s into this object. - SerializeFrom(s *SignalAct) - - // DeserializeTo copies the data in this object into the host SignalAct s. - DeserializeTo(s *SignalAct) -} diff --git a/pkg/sentry/arch/signal_amd64.go b/pkg/sentry/arch/signal_amd64.go index 082ed92b1..0bf272e16 100644 --- a/pkg/sentry/arch/signal_amd64.go +++ b/pkg/sentry/arch/signal_amd64.go @@ -81,11 +81,6 @@ type UContext64 struct { Sigset linux.SignalSet } -// NewSignalAct implements Context.NewSignalAct. -func (c *context64) NewSignalAct() NativeSignalAct { - return &SignalAct{} -} - // NewSignalStack implements Context.NewSignalStack. func (c *context64) NewSignalStack() NativeSignalStack { return &SignalStack{} @@ -110,7 +105,7 @@ func (c *context64) fpuFrameSize() (size int, useXsave bool) { // SignalSetup implements Context.SignalSetup. (Compare to Linux's // arch/x86/kernel/signal.c:__setup_rt_frame().) -func (c *context64) SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt *SignalStack, sigset linux.SignalSet) error { +func (c *context64) SignalSetup(st *Stack, act *linux.SigAction, info *SignalInfo, alt *SignalStack, sigset linux.SignalSet) error { sp := st.Bottom // "The 128-byte area beyond the location pointed to by %rsp is considered @@ -187,7 +182,7 @@ func (c *context64) SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt // Prior to proceeding, figure out if the frame will exhaust the range // for the signal stack. This is not allowed, and should immediately // force signal delivery (reverting to the default handler). - if act.IsOnStack() && alt.IsEnabled() && !alt.Contains(frameBottom) { + if act.Flags&linux.SA_ONSTACK != 0 && alt.IsEnabled() && !alt.Contains(frameBottom) { return unix.EFAULT } @@ -203,7 +198,7 @@ func (c *context64) SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt return err } ucAddr := st.Bottom - if act.HasRestorer() { + if act.Flags&linux.SA_RESTORER != 0 { // Push the restorer return address. // Note that this doesn't need to be popped. if _, err := primitive.CopyUint64Out(st, StackBottomMagic, act.Restorer); err != nil { diff --git a/pkg/sentry/arch/signal_arm64.go b/pkg/sentry/arch/signal_arm64.go index da71fb873..cc3c6ce62 100644 --- a/pkg/sentry/arch/signal_arm64.go +++ b/pkg/sentry/arch/signal_arm64.go @@ -71,18 +71,13 @@ type UContext64 struct { MContext SignalContext64 } -// NewSignalAct implements Context.NewSignalAct. -func (c *context64) NewSignalAct() NativeSignalAct { - return &SignalAct{} -} - // NewSignalStack implements Context.NewSignalStack. func (c *context64) NewSignalStack() NativeSignalStack { return &SignalStack{} } // SignalSetup implements Context.SignalSetup. -func (c *context64) SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt *SignalStack, sigset linux.SignalSet) error { +func (c *context64) SignalSetup(st *Stack, act *linux.SigAction, info *SignalInfo, alt *SignalStack, sigset linux.SignalSet) error { sp := st.Bottom // Construct the UContext64 now since we need its size. @@ -114,7 +109,7 @@ func (c *context64) SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt // Prior to proceeding, figure out if the frame will exhaust the range // for the signal stack. This is not allowed, and should immediately // force signal delivery (reverting to the default handler). - if act.IsOnStack() && alt.IsEnabled() && !alt.Contains(frameBottom) { + if act.Flags&linux.SA_ONSTACK != 0 && alt.IsEnabled() && !alt.Contains(frameBottom) { return unix.EFAULT } @@ -137,7 +132,7 @@ func (c *context64) SignalSetup(st *Stack, act *SignalAct, info *SignalInfo, alt c.Regs.Regs[0] = uint64(info.Signo) c.Regs.Regs[1] = uint64(infoAddr) c.Regs.Regs[2] = uint64(ucAddr) - c.Regs.Regs[30] = uint64(act.Restorer) + c.Regs.Regs[30] = act.Restorer // Save the thread's floating point state. c.sigFPState = append(c.sigFPState, c.fpState) diff --git a/pkg/sentry/kernel/signal_handlers.go b/pkg/sentry/kernel/signal_handlers.go index 768fda220..147cc41bb 100644 --- a/pkg/sentry/kernel/signal_handlers.go +++ b/pkg/sentry/kernel/signal_handlers.go @@ -16,7 +16,6 @@ package kernel import ( "gvisor.dev/gvisor/pkg/abi/linux" - "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sync" ) @@ -30,14 +29,14 @@ type SignalHandlers struct { mu sync.Mutex `state:"nosave"` // actions is the action to be taken upon receiving each signal. - actions map[linux.Signal]arch.SignalAct + actions map[linux.Signal]linux.SigAction } // NewSignalHandlers returns a new SignalHandlers specifying all default // actions. func NewSignalHandlers() *SignalHandlers { return &SignalHandlers{ - actions: make(map[linux.Signal]arch.SignalAct), + actions: make(map[linux.Signal]linux.SigAction), } } @@ -59,9 +58,9 @@ func (sh *SignalHandlers) CopyForExec() *SignalHandlers { sh.mu.Lock() defer sh.mu.Unlock() for sig, act := range sh.actions { - if act.Handler == arch.SignalActIgnore { - sh2.actions[sig] = arch.SignalAct{ - Handler: arch.SignalActIgnore, + if act.Handler == linux.SIG_IGN { + sh2.actions[sig] = linux.SigAction{ + Handler: linux.SIG_IGN, } } } @@ -73,15 +72,15 @@ func (sh *SignalHandlers) IsIgnored(sig linux.Signal) bool { sh.mu.Lock() defer sh.mu.Unlock() sa, ok := sh.actions[sig] - return ok && sa.Handler == arch.SignalActIgnore + return ok && sa.Handler == linux.SIG_IGN } // dequeueActionLocked returns the SignalAct that should be used to handle sig. // // Preconditions: sh.mu must be locked. -func (sh *SignalHandlers) dequeueAction(sig linux.Signal) arch.SignalAct { +func (sh *SignalHandlers) dequeueAction(sig linux.Signal) linux.SigAction { act := sh.actions[sig] - if act.IsResetHandler() { + if act.Flags&linux.SA_RESETHAND != 0 { delete(sh.actions, sig) } return act diff --git a/pkg/sentry/kernel/task_exit.go b/pkg/sentry/kernel/task_exit.go index 385385d1e..5b17c0065 100644 --- a/pkg/sentry/kernel/task_exit.go +++ b/pkg/sentry/kernel/task_exit.go @@ -670,10 +670,10 @@ func (t *Task) exitNotifyLocked(fromPtraceDetach bool) { t.parent.tg.signalHandlers.mu.Lock() if t.tg.terminationSignal == linux.SIGCHLD || fromPtraceDetach { if act, ok := t.parent.tg.signalHandlers.actions[linux.SIGCHLD]; ok { - if act.Handler == arch.SignalActIgnore { + if act.Handler == linux.SIG_IGN { t.exitParentAcked = true signalParent = false - } else if act.Flags&arch.SignalFlagNoCldWait != 0 { + } else if act.Flags&linux.SA_NOCLDWAIT != 0 { t.exitParentAcked = true } } diff --git a/pkg/sentry/kernel/task_signals.go b/pkg/sentry/kernel/task_signals.go index c2b9fc08f..466256fe4 100644 --- a/pkg/sentry/kernel/task_signals.go +++ b/pkg/sentry/kernel/task_signals.go @@ -86,7 +86,7 @@ var defaultActions = map[linux.Signal]SignalAction{ } // computeAction figures out what to do given a signal number -// and an arch.SignalAct. SIGSTOP always results in a SignalActionStop, +// and an linux.SigAction. SIGSTOP always results in a SignalActionStop, // and SIGKILL always results in a SignalActionTerm. // Signal 0 is always ignored as many programs use it for various internal functions // and don't expect it to do anything. @@ -97,7 +97,7 @@ var defaultActions = map[linux.Signal]SignalAction{ // 0, the default action is taken; // 1, the signal is ignored; // anything else, the function returns SignalActionHandler. -func computeAction(sig linux.Signal, act arch.SignalAct) SignalAction { +func computeAction(sig linux.Signal, act linux.SigAction) SignalAction { switch sig { case linux.SIGSTOP: return SignalActionStop @@ -108,9 +108,9 @@ func computeAction(sig linux.Signal, act arch.SignalAct) SignalAction { } switch act.Handler { - case arch.SignalActDefault: + case linux.SIG_DFL: return defaultActions[sig] - case arch.SignalActIgnore: + case linux.SIG_IGN: return SignalActionIgnore default: return SignalActionHandler @@ -155,7 +155,7 @@ func (t *Task) PendingSignals() linux.SignalSet { } // deliverSignal delivers the given signal and returns the following run state. -func (t *Task) deliverSignal(info *arch.SignalInfo, act arch.SignalAct) taskRunState { +func (t *Task) deliverSignal(info *arch.SignalInfo, act linux.SigAction) taskRunState { sigact := computeAction(linux.Signal(info.Signo), act) if t.haveSyscallReturn { @@ -172,7 +172,7 @@ func (t *Task) deliverSignal(info *arch.SignalInfo, act arch.SignalAct) taskRunS fallthrough case sre == syserror.ERESTART_RESTARTBLOCK: fallthrough - case (sre == syserror.ERESTARTSYS && !act.IsRestart()): + case (sre == syserror.ERESTARTSYS && act.Flags&linux.SA_RESTART == 0): t.Debugf("Not restarting syscall %d after errno %d: interrupted by signal %d", t.Arch().SyscallNo(), sre, info.Signo) t.Arch().SetReturn(uintptr(-ExtractErrno(syserror.EINTR, -1))) default: @@ -236,7 +236,7 @@ func (t *Task) deliverSignal(info *arch.SignalInfo, act arch.SignalAct) taskRunS // deliverSignalToHandler changes the task's userspace state to enter the given // user-configured handler for the given signal. -func (t *Task) deliverSignalToHandler(info *arch.SignalInfo, act arch.SignalAct) error { +func (t *Task) deliverSignalToHandler(info *arch.SignalInfo, act linux.SigAction) error { // Signal delivery to an application handler interrupts restartable // sequences. t.rseqInterrupt() @@ -248,7 +248,7 @@ func (t *Task) deliverSignalToHandler(info *arch.SignalInfo, act arch.SignalAct) // N.B. This is a *copy* of the alternate stack that the user's signal // handler expects to see in its ucontext (even if it's not in use). alt := t.signalStack - if act.IsOnStack() && alt.IsEnabled() { + if act.Flags&linux.SA_ONSTACK != 0 && alt.IsEnabled() { alt.SetOnStack() if !alt.Contains(sp) { sp = hostarch.Addr(alt.Top()) @@ -289,7 +289,7 @@ func (t *Task) deliverSignalToHandler(info *arch.SignalInfo, act arch.SignalAct) // Add our signal mask. newMask := t.signalMask | act.Mask - if !act.IsNoDefer() { + if act.Flags&linux.SA_NODEFER == 0 { newMask |= linux.SignalSetOf(linux.Signal(info.Signo)) } t.SetSignalMask(newMask) @@ -572,9 +572,9 @@ func (t *Task) forceSignal(sig linux.Signal, unconditional bool) { func (t *Task) forceSignalLocked(sig linux.Signal, unconditional bool) { blocked := linux.SignalSetOf(sig)&t.signalMask != 0 act := t.tg.signalHandlers.actions[sig] - ignored := act.Handler == arch.SignalActIgnore + ignored := act.Handler == linux.SIG_IGN if blocked || ignored || unconditional { - act.Handler = arch.SignalActDefault + act.Handler = linux.SIG_DFL t.tg.signalHandlers.actions[sig] = act if blocked { t.setSignalMaskLocked(t.signalMask &^ linux.SignalSetOf(sig)) @@ -680,11 +680,11 @@ func (t *Task) SetSignalStack(alt arch.SignalStack) bool { return true } -// SetSignalAct atomically sets the thread group's signal action for signal sig +// SetSigAction atomically sets the thread group's signal action for signal sig // to *actptr (if actptr is not nil) and returns the old signal action. -func (tg *ThreadGroup) SetSignalAct(sig linux.Signal, actptr *arch.SignalAct) (arch.SignalAct, error) { +func (tg *ThreadGroup) SetSigAction(sig linux.Signal, actptr *linux.SigAction) (linux.SigAction, error) { if !sig.IsValid() { - return arch.SignalAct{}, syserror.EINVAL + return linux.SigAction{}, syserror.EINVAL } tg.pidns.owner.mu.RLock() @@ -718,27 +718,6 @@ func (tg *ThreadGroup) SetSignalAct(sig linux.Signal, actptr *arch.SignalAct) (a return oldact, nil } -// CopyOutSignalAct converts the given SignalAct into an architecture-specific -// type and then copies it out to task memory. -func (t *Task) CopyOutSignalAct(addr hostarch.Addr, s *arch.SignalAct) error { - n := t.Arch().NewSignalAct() - n.SerializeFrom(s) - _, err := n.CopyOut(t, addr) - return err -} - -// CopyInSignalAct copies an architecture-specific sigaction type from task -// memory and then converts it into a SignalAct. -func (t *Task) CopyInSignalAct(addr hostarch.Addr) (arch.SignalAct, error) { - n := t.Arch().NewSignalAct() - var s arch.SignalAct - if _, err := n.CopyIn(t, addr); err != nil { - return s, err - } - n.DeserializeTo(&s) - return s, nil -} - // CopyOutSignalStack converts the given SignalStack into an // architecture-specific type and then copies it out to task memory. func (t *Task) CopyOutSignalStack(addr hostarch.Addr, s *arch.SignalStack) error { @@ -909,7 +888,7 @@ func (t *Task) signalStop(target *Task, code int32, status int32) { t.tg.signalHandlers.mu.Lock() defer t.tg.signalHandlers.mu.Unlock() act, ok := t.tg.signalHandlers.actions[linux.SIGCHLD] - if !ok || (act.Handler != arch.SignalActIgnore && act.Flags&arch.SignalFlagNoCldStop == 0) { + if !ok || (act.Handler != linux.SIG_IGN && act.Flags&linux.SA_NOCLDSTOP == 0) { sigchld := &arch.SignalInfo{ Signo: int32(linux.SIGCHLD), Code: code, diff --git a/pkg/sentry/sighandling/sighandling_unsafe.go b/pkg/sentry/sighandling/sighandling_unsafe.go index d6a2fbe34..3fe5c6770 100644 --- a/pkg/sentry/sighandling/sighandling_unsafe.go +++ b/pkg/sentry/sighandling/sighandling_unsafe.go @@ -21,25 +21,16 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" ) -// FIXME(gvisor.dev/issue/214): Move to pkg/abi/linux along with definitions in -// pkg/sentry/arch. -type sigaction struct { - handler uintptr - flags uint64 - restorer uintptr - mask uint64 -} - // IgnoreChildStop sets the SA_NOCLDSTOP flag, causing child processes to not // generate SIGCHLD when they stop. func IgnoreChildStop() error { - var sa sigaction + var sa linux.SigAction // Get the existing signal handler information, and set the flag. if _, _, e := unix.RawSyscall6(unix.SYS_RT_SIGACTION, uintptr(unix.SIGCHLD), 0, uintptr(unsafe.Pointer(&sa)), linux.SignalSetSize, 0, 0); e != 0 { return e } - sa.flags |= linux.SA_NOCLDSTOP + sa.Flags |= linux.SA_NOCLDSTOP if _, _, e := unix.RawSyscall6(unix.SYS_RT_SIGACTION, uintptr(unix.SIGCHLD), uintptr(unsafe.Pointer(&sa)), 0, linux.SignalSetSize, 0, 0); e != 0 { return e } diff --git a/pkg/sentry/strace/signal.go b/pkg/sentry/strace/signal.go index e5b379a20..5afc9525b 100644 --- a/pkg/sentry/strace/signal.go +++ b/pkg/sentry/strace/signal.go @@ -130,8 +130,8 @@ func sigAction(t *kernel.Task, addr hostarch.Addr) string { return "null" } - sa, err := t.CopyInSignalAct(addr) - if err != nil { + var sa linux.SigAction + if _, err := sa.CopyIn(t, addr); err != nil { return fmt.Sprintf("%#x (error copying sigaction: %v)", addr, err) } diff --git a/pkg/sentry/syscalls/linux/sys_signal.go b/pkg/sentry/syscalls/linux/sys_signal.go index 53b12dc41..1249c31a2 100644 --- a/pkg/sentry/syscalls/linux/sys_signal.go +++ b/pkg/sentry/syscalls/linux/sys_signal.go @@ -251,20 +251,20 @@ func RtSigaction(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.S return 0, nil, syserror.EINVAL } - var newactptr *arch.SignalAct + var newactptr *linux.SigAction if newactarg != 0 { - newact, err := t.CopyInSignalAct(newactarg) - if err != nil { + var newact linux.SigAction + if _, err := newact.CopyIn(t, newactarg); err != nil { return 0, nil, err } newactptr = &newact } - oldact, err := t.ThreadGroup().SetSignalAct(sig, newactptr) + oldact, err := t.ThreadGroup().SetSigAction(sig, newactptr) if err != nil { return 0, nil, err } if oldactarg != 0 { - if err := t.CopyOutSignalAct(oldactarg, &oldact); err != nil { + if _, err := oldact.CopyOut(t, oldactarg); err != nil { return 0, nil, err } } |