func StackInit(u models.Usercorn, args, env []string, auxv []byte) error {
// push argv and envp strings
envp, err := pushStrings(u, env...)
if err != nil {
return err
}
argv, err := pushStrings(u, args...)
if err != nil {
return err
}
// align stack pointer
sp, _ := u.RegRead(u.Arch().SP)
u.RegWrite(u.Arch().SP, (sp & ^uint64(15)))
// end marker
if _, err := u.Push(0); err != nil {
return err
}
// auxv
if len(auxv) > 0 {
if _, err := u.PushBytes(auxv); err != nil {
return err
}
}
// envp
if err := pushAddrs(u, envp); err != nil {
return err
}
// argv
if err := pushAddrs(u, argv); err != nil {
return err
}
// argc
_, err = u.Push(uint64(len(args)))
return err
}
func StackArgs(u models.Usercorn) func(n int) ([]uint64, error) {
return func(n int) ([]uint64, error) {
sp, _ := u.RegRead(u.Arch().SP)
// starts with an empty slot
s := u.StrucAt(sp + uint64(u.Bits()/8))
ret := make([]uint64, n)
for i := 0; i < n; i++ {
var arg uint64
var err error
// TODO: simplify this when struc issue #47 is fixed
if u.Bits() == 64 {
err = s.Unpack(&arg)
} else {
var arg32 uint32
err = s.Unpack(&arg32)
arg = uint64(arg32)
}
if err != nil {
return nil, err
}
ret[i] = arg
}
return ret, nil
}
}
func StackInit(u models.Usercorn, args, env []string, auxv []byte) error {
if _, err := u.Push(0); err != nil {
return err
}
if len(args) > 0 {
if _, err := u.PushBytes([]byte(args[0] + "\x00")); err != nil {
return err
}
}
// push argv and envp strings
envp, err := pushStrings(u, env...)
if err != nil {
return err
}
argv, err := pushStrings(u, args...)
if err != nil {
return err
}
// precalc envp -> argc for stack alignment
envpb, err := packAddrs(u, envp)
if err != nil {
return err
}
argvb, err := packAddrs(u, argv)
if err != nil {
return err
}
var tmp [8]byte
argcb, err := u.PackAddr(tmp[:], uint64(len(argv)))
init := append(argcb, argvb...)
init = append(init, envpb...)
// align stack pointer
sp, _ := u.RegRead(u.Arch().SP)
sp &= ^uint64(15)
off := len(init) & 15
if off > 0 {
sp -= uint64(16 - off)
}
u.RegWrite(u.Arch().SP, sp)
// auxv
if len(auxv) > 0 {
if _, err := u.PushBytes(auxv); err != nil {
return err
}
}
// write envp -> argc
u.PushBytes(init)
return err
}