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 pushAddrs(u models.Usercorn, addrs []uint64) error {
if _, err := u.Push(0); err != nil {
return err
}
for i, _ := range addrs {
if _, err := u.Push(addrs[len(addrs)-i-1]); err != nil {
return err
}
}
return 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
}
func StackInit(u models.Usercorn, args, env []string) error {
exe := u.Exe()
addr, err := u.PushBytes([]byte(exe + "\x00"))
if err != nil {
return err
}
var tmp [8]byte
auxv, err := u.PackAddr(tmp[:], addr)
if err != nil {
return err
}
err = posix.StackInit(u, args, env, auxv)
if err != nil {
return err
}
// offset to mach_header at exe[0:] in guest memory
textOffset, _, _ := u.Loader().Header()
offset := u.Base() + textOffset
_, err = u.Push(offset)
return err
}