minix/kernel/system/old/do_fork.c
2005-04-21 14:53:53 +00:00

64 lines
1.7 KiB
C

/* The system call implemented in this file:
* m_type: SYS_FORK
*
* The parameters for this system call are:
* m1_i1: PR_PROC_NR (child's process table slot)
* m1_i2: PR_PPROC_NR (parent, process that forked)
* m1_i3: PR_PID (child pid received from MM)
*/
#include "../kernel.h"
#include "../system.h"
#include <signal.h>
#include "../sendmask.h"
INIT_ASSERT
/*===========================================================================*
* do_fork *
*===========================================================================*/
PUBLIC int do_fork(m_ptr)
register message *m_ptr; /* pointer to request message */
{
/* Handle sys_fork(). PR_PPROC_NR has forked. The child is PR_PROC_NR. */
#if (CHIP == INTEL)
reg_t old_ldt_sel;
#endif
register struct proc *rpc;
struct proc *rpp;
rpp = proc_addr(m_ptr->PR_PPROC_NR);
assert(isuserp(rpp));
rpc = proc_addr(m_ptr->PR_PROC_NR);
assert(isemptyp(rpc));
/* Copy parent 'proc' struct to child. */
#if (CHIP == INTEL)
old_ldt_sel = rpc->p_ldt_sel; /* stop this being obliterated by copy */
#endif
*rpc = *rpp; /* copy 'proc' struct */
#if (CHIP == INTEL)
rpc->p_ldt_sel = old_ldt_sel;
#endif
rpc->p_nr = m_ptr->PR_PROC_NR; /* this was obliterated by copy */
rpc->p_flags |= NO_MAP; /* inhibit the process from running */
rpc->p_flags &= ~(PENDING | SIG_PENDING | P_STOP);
/* Only 1 in group should have PENDING, child does not inherit trace status*/
sigemptyset(&rpc->p_pending);
rpc->p_pendcount = 0;
rpc->p_reg.retreg = 0; /* child sees pid = 0 to know it is child */
rpc->user_time = 0; /* set all the accounting times to 0 */
rpc->sys_time = 0;
rpc->child_utime = 0;
rpc->child_stime = 0;
return(OK);
}