diff options
Diffstat (limited to 'prog/encodingexec.go')
| -rw-r--r-- | prog/encodingexec.go | 33 |
1 files changed, 20 insertions, 13 deletions
diff --git a/prog/encodingexec.go b/prog/encodingexec.go index b89788378..86ec1f638 100644 --- a/prog/encodingexec.go +++ b/prog/encodingexec.go @@ -6,11 +6,11 @@ // Exec format is an sequence of uint64's which encodes a sequence of calls. // The sequence is terminated by a speciall call execInstrEOF. -// Each call is (call ID, number of arguments, arguments...). +// Each call is (call ID, copyout index, number of arguments, arguments...). // Each argument is (type, size, value). // There are 4 types of arguments: // - execArgConst: value is const value -// - execArgResult: value is index of a call whose result we want to reference +// - execArgResult: value is copyout index we want to reference // - execArgData: value is a binary blob (represented as ]size/8[ uint64's) // - execArgCsum: runtime checksum calculation // There are 2 other special calls: @@ -48,6 +48,7 @@ const ( const ( ExecBufferSize = 2 << 20 + ExecNoCopyout = ^uint64(0) ) type Args []Arg @@ -78,7 +79,7 @@ func (p *Prog) SerializeForExec(buffer []byte, pid int) (int, error) { panic(fmt.Errorf("serializing invalid program: %v", err)) } } - instrSeq := 0 + var copyoutSeq uint64 w := &execContext{ target: p.Target, buf: buffer, @@ -125,7 +126,6 @@ func (p *Prog) SerializeForExec(buffer []byte, pid int) (int, error) { w.write(execInstrCopyin) w.write(addr) w.writeArg(arg1, pid) - instrSeq++ } }) } @@ -168,19 +168,21 @@ func (p *Prog) SerializeForExec(buffer []byte, pid int) (int, error) { default: panic(fmt.Sprintf("csum arg has unknown kind %v", csumMap[arg].Kind)) } - instrSeq++ } } // Generate the call itself. w.write(uint64(c.Meta.ID)) + if isUsed(c.Ret) { + w.args[c.Ret] = argInfo{Idx: copyoutSeq} + w.write(copyoutSeq) + copyoutSeq++ + } else { + w.write(ExecNoCopyout) + } w.write(uint64(len(c.Args))) for _, arg := range c.Args { w.writeArg(arg, pid) } - if isUsed(c.Ret) { - w.args[c.Ret] = argInfo{Idx: instrSeq} - } - instrSeq++ // Generate copyout instructions that persist interesting return values. foreachArg(c, func(arg, base Arg, _ *[]Arg) { if !isUsed(arg) { @@ -195,10 +197,11 @@ func (p *Prog) SerializeForExec(buffer []byte, pid int) (int, error) { panic("arg base is not a pointer") } info := w.args[arg] - info.Idx = instrSeq - instrSeq++ + info.Idx = copyoutSeq + copyoutSeq++ w.args[arg] = info w.write(execInstrCopyout) + w.write(info.Idx) w.write(info.Addr) w.write(arg.Size()) default: @@ -236,7 +239,7 @@ type execContext struct { type argInfo struct { Addr uint64 // physical addr - Idx int // instruction index + Idx uint64 // copyout instruction index } func (w *execContext) write(v uint64) { @@ -271,9 +274,13 @@ func (w *execContext) writeArg(arg Arg, pid int) { w.write(0) // bit field offset w.write(0) // bit field length } else { + info, ok := w.args[a.Res] + if !ok { + panic("no copyout index") + } w.write(execArgResult) w.write(a.Size()) - w.write(uint64(w.args[a.Res].Idx)) + w.write(info.Idx) w.write(a.OpDiv) w.write(a.OpAdd) } |