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glibc  2.9
Classes | Functions
hurdstartup.h File Reference
#include <stdint.h>
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Classes

struct  hurd_startup_data

Functions

void _hurd_startup (void **argptr, void(*main)(intptr_t *data))

Class Documentation

struct hurd_startup_data

Definition at line 37 of file hurdstartup.h.

Class Members
mach_port_t * dtable
mach_msg_type_number_t dtablesize
int flags
int * intarray
mach_msg_type_number_t intarraysize
vm_address_t phdr
vm_size_t phdrsz
mach_port_t * portarray
mach_msg_type_number_t portarraysize
vm_address_t stack_base
vm_size_t stack_size
vm_address_t user_entry

Function Documentation

void _hurd_startup ( void **  argptr,
void(*)(intptr_t *data main 
)

Definition at line 58 of file hurdstartup.c.

{
  error_t err;
  mach_port_t in_bootstrap;
  char *args, *env;
  mach_msg_type_number_t argslen, envlen;
  struct hurd_startup_data data;
  char **argv, **envp;
  int argc, envc;
  intptr_t *argcptr;
  vm_address_t addr;

  /* Attempt to map page zero redzoned before we receive any RPC
     data that might get allocated there.  We can ignore errors.  */
  addr = 0;
  __vm_map (__mach_task_self (),
           &addr, __vm_page_size, 0, 0, MACH_PORT_NULL, 0, 1,
           VM_PROT_NONE, VM_PROT_NONE, VM_INHERIT_COPY);

  if (err = __task_get_special_port (__mach_task_self (), TASK_BOOTSTRAP_PORT,
                                 &in_bootstrap))
    LOSE;

  if (in_bootstrap != MACH_PORT_NULL)
    {
      /* Call the exec server on our bootstrap port and
        get all our standard information from it.  */

      argslen = envlen = 0;
      data.dtablesize = data.portarraysize = data.intarraysize = 0;

      err = __exec_startup_get_info (in_bootstrap,
                                 &data.user_entry,
                                 &data.phdr, &data.phdrsz,
                                 &data.stack_base, &data.stack_size,
                                 &data.flags,
                                 &args, &argslen,
                                 &env, &envlen,
                                 &data.dtable, &data.dtablesize,
                                 &data.portarray, &data.portarraysize,
                                 &data.intarray, &data.intarraysize);
      __mach_port_deallocate (__mach_task_self (), in_bootstrap);
    }

  if (err || in_bootstrap == MACH_PORT_NULL || (data.flags & EXEC_STACK_ARGS))
    {
      /* Either we have no bootstrap port, or the RPC to the exec server
        failed, or whoever started us up passed the flag saying args are
        on the stack.  Try to snarf the args in the canonical Mach way.
        Hopefully either they will be on the stack as expected, or the
        stack will be zeros so we don't crash.  */

      argcptr = (intptr_t *) argptr;
      argc = argcptr[0];
      argv = (char **) &argcptr[1];
      envp = &argv[argc + 1];
      envc = 0;
      while (envp[envc])
       ++envc;
    }
  else
    {
      /* Turn the block of null-separated strings we were passed for the
        arguments and environment into vectors of pointers to strings.  */

      /* Count up the arguments so we can allocate ARGV.  */
      argc = __argz_count (args, argslen);
      /* Count up the environment variables so we can allocate ENVP.  */
      envc = __argz_count (env, envlen);

      /* There were some arguments.  Allocate space for the vectors of
        pointers and fill them in.  We allocate the space for the
        environment pointers immediately after the argv pointers because
        the ELF ABI will expect it.  */
      argcptr = __alloca (sizeof (intptr_t) +
                       (argc + 1 + envc + 1) * sizeof (char *) +
                       sizeof (struct hurd_startup_data));
      *argcptr = argc;
      argv = (void *) (argcptr + 1);
      __argz_extract (args, argslen, argv);

      /* There was some environment.  */
      envp = &argv[argc + 1];
      __argz_extract (env, envlen, envp);
    }

  if (err || in_bootstrap == MACH_PORT_NULL)
    {
      /* Either we have no bootstrap port, or the RPC to the exec server
        failed.  Set all our other variables to have empty information.  */

      data.flags = 0;
      args = env = NULL;
      argslen = envlen = 0;
      data.dtable = NULL;
      data.dtablesize = 0;
      data.portarray = NULL;
      data.portarraysize = 0;
      data.intarray = NULL;
      data.intarraysize = 0;
    }
  else if ((void *) &envp[envc + 1] == argv[0])
    {
      /* The arguments arrived on the stack from the kernel, but our
        protocol requires some space after them for a `struct
        hurd_startup_data'.  Move them.  */
      struct
       {
         intptr_t count;
         char *argv[argc + 1];
         char *envp[envc + 1];
         struct hurd_startup_data data;
       } *args = alloca (sizeof *args);
      if ((void *) &args[1] == (void *) argcptr)
       args = alloca (-((char *) &args->data - (char *) args));
      memmove (args, argcptr, (char *) &args->data - (char *) args);
      argcptr = (void *) args;
      argv = args->argv;
      envp = args->envp;
    }

  {
    struct hurd_startup_data *d = (void *) &envp[envc + 1];

    if ((void *) d != argv[0])
      {
       *d = data;
       _hurd_init_dtable = d->dtable;
       _hurd_init_dtablesize = d->dtablesize;
      }

    (*main) (argcptr);
  }

  /* Should never get here.  */
  LOSE;
  abort ();
}

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