minix/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  *   m_lsys_krn_sys_exec.endpt          (process that did exec call)
   6  *   m_lsys_krn_sys_exec.stack          (new stack pointer)
   7  *   m_lsys_krn_sys_exec.name           (pointer to program name)
   8  *   m_lsys_krn_sys_exec.ip             (new instruction pointer)
   9  *   m_lsys_krn_sys_exec.ps_str         (struct ps_strings *)
  10  */
  11 #include "kernel/system.h"
  12 #include <string.h>
  13 #include <minix/endpoint.h>
  14
  15 #if USE_EXEC
  16
  17 /*===========================================================================*
  18  *                              do_exec                                      *
  19  *===========================================================================*/
  20 int do_exec(struct proc * caller, message * m_ptr)
  21 {
  22 /* Handle sys_exec().  A process has done a successful EXEC. Patch it up. */
  23   register struct proc *rp;
  24   int proc_nr;
  25   char name[PROC_NAME_LEN];
  26
  27   if(!isokendpt(m_ptr->m_lsys_krn_sys_exec.endpt, &proc_nr))
  28         return EINVAL;
  29
  30   rp = proc_addr(proc_nr);
  31
  32   if(rp->p_misc_flags & MF_DELIVERMSG) {
  33         rp->p_misc_flags &= ~MF_DELIVERMSG;
  34   }
  35
  36   /* Save command name for debugging, ps(1) output, etc. */
  37   if(data_copy(caller->p_endpoint, m_ptr->m_lsys_krn_sys_exec.name,
  38         KERNEL, (vir_bytes) name,
  39         (phys_bytes) sizeof(name) - 1) != OK)
  40         strncpy(name, "<unset>", PROC_NAME_LEN);
  41
  42   name[sizeof(name)-1] = '\0';
  43
  44   /* Set process state. */
  45   arch_proc_init(rp,
  46         (u32_t) m_ptr->m_lsys_krn_sys_exec.ip,
  47         (u32_t) m_ptr->m_lsys_krn_sys_exec.stack,
  48         (u32_t) m_ptr->m_lsys_krn_sys_exec.ps_str, name);
  49
  50   /* No reply to EXEC call */
  51   RTS_UNSET(rp, RTS_RECEIVING);
  52
  53   /* Mark fpu_regs contents as not significant, so fpu
  54    * will be initialized, when it's used next time. */
  55   rp->p_misc_flags &= ~MF_FPU_INITIALIZED;
  56   /* force reloading FPU if the current process is the owner */
  57   release_fpu(rp);
  58   return(OK);
  59 }
  60 #endif /* USE_EXEC */