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glibc  2.9
Classes | Defines | Functions
makecontext.c File Reference
#include <libintl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <ucontext.h>
#include <sys/rse.h>

Go to the source code of this file.

Classes

struct  fdesc

Defines

#define PUSH(val)

Functions

void __makecontext (ucontext_t *ucp, void(*func)(void), int argc,...)

Define Documentation

#define PUSH (   val)
Value:
do {                                      \
  if (ia64_rse_is_rnat_slot (rbs))        \
    *rbs++ = 0;                                  \
  *rbs++ = (val);                         \
} while (0)

Definition at line 34 of file makecontext.c.


Function Documentation

void __makecontext ( ucontext_t ucp,
void(*)(void)  func,
int  argc,
  ... 
)

Definition at line 46 of file makecontext.c.

{
  struct sigcontext *sc = &ucp->uc_mcontext;
  extern void __start_context (ucontext_t *link, long gp, ...);
  unsigned long stack_start, stack_end;
  va_list ap;
  long *rbs;
  int i;

  stack_start = (long) sc->sc_stack.ss_sp;
  stack_end = (long) sc->sc_stack.ss_sp + sc->sc_stack.ss_size;

  stack_start = (stack_start + 7) & -8;
  stack_end = stack_end & -16;

  if (argc > 8)
    {
      fprintf (stderr, _("\
makecontext: does not know how to handle more than 8 arguments\n"));
      exit (-1);
    }

  /* set the entry point and global pointer: */
  sc->sc_br[0] = ((struct fdesc *) &__start_context)->ip;
  sc->sc_br[1] = ((struct fdesc *) func)->ip;
  sc->sc_gr[1] = ((struct fdesc *) func)->gp;

  /* set up the call frame: */
  sc->sc_ar_pfs = ((sc->sc_ar_pfs & ~0x3fffffffffUL)
                 | (argc + 2) | ((argc + 2) << 7));
  rbs = (long *) stack_start;
  PUSH((long) ucp->uc_link);
  PUSH(((struct fdesc *) &__start_context)->gp);
  va_start (ap, argc);
  for (i = 0; i < argc; ++i)
    PUSH(va_arg (ap, long));
  va_end (ap);

  /* set the memory and register stack pointers: */
  sc->sc_ar_bsp = (long) rbs;
  sc->sc_gr[12] = stack_end - 16;

  /* clear the NaT bits for r1 and r12: */
  sc->sc_nat &= ~((1 << 1) | (1 << 12));
  sc->sc_ar_rnat = 0;
}

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