kernel/system/do_exec.c

   1 /* The kernel call implemented in this file:
   2  *   m_type:    SYS_EXEC
   3  *
   4  * The parameters for this kernel call are:
   5  *    m1_i1:    PR_ENDPT                (process that did exec call)
   6  *    m1_p1:    PR_STACK_PTR            (new stack pointer)
   7  *    m1_p2:    PR_NAME_PTR             (pointer to program name)
   8  *    m1_p3:    PR_IP_PTR               (new instruction pointer)
   9  */
  10 #include "kernel/system.h"
  11 #include <string.h>
  12 #include <minix/endpoint.h>
  13
  14 #if USE_EXEC
  15
  16 /*===========================================================================*
  17  *                              do_exec                                      *
  18  *===========================================================================*/
  19 int do_exec(struct proc * caller, message * m_ptr)
  20 {
  21 /* Handle sys_exec().  A process has done a successful EXEC. Patch it up. */
  22   register struct proc *rp;
  23   int proc_nr;
  24   char name[PROC_NAME_LEN];
  25
  26   if(!isokendpt(m_ptr->PR_ENDPT, &proc_nr))
  27         return EINVAL;
  28
  29   rp = proc_addr(proc_nr);
  30
  31   if(rp->p_misc_flags & MF_DELIVERMSG) {
  32         rp->p_misc_flags &= ~MF_DELIVERMSG;
  33   }
  34
  35   /* Save command name for debugging, ps(1) output, etc. */
  36   if(data_copy(caller->p_endpoint, (vir_bytes) m_ptr->PR_NAME_PTR,
  37         KERNEL, (vir_bytes) name,
  38         (phys_bytes) sizeof(name) - 1) != OK)
  39         strncpy(name, "<unset>", PROC_NAME_LEN);
  40
  41   name[sizeof(name)-1] = '\0';
  42
  43   /* Set process state. */
  44   arch_proc_init(rp, (u32_t) m_ptr->PR_IP_PTR, (u32_t) m_ptr->PR_STACK_PTR, name);
  45
  46   /* No reply to EXEC call */
  47   RTS_UNSET(rp, RTS_RECEIVING);
  48
  49   /* Mark fpu_regs contents as not significant, so fpu
  50    * will be initialized, when it's used next time. */
  51   rp->p_misc_flags &= ~MF_FPU_INITIALIZED;
  52   /* force reloading FPU if the current process is the owner */
  53   release_fpu(rp);
  54   return(OK);
  55 }
  56 #endif /* USE_EXEC */
  57