minix/servers/pm/trace.c

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/* This file handles the process manager's part of debugging, using the
* ptrace system call. Most of the commands are passed on to the system
* task for completion.
*
* The debugging commands available are:
* T_STOP stop the process
* T_OK enable tracing by parent for this process
* T_GETINS return value from instruction space
* T_GETDATA return value from data space
* T_GETUSER return value from user process table
* T_SETINS set value in instruction space
* T_SETDATA set value in data space
* T_SETUSER set value in user process table
* T_RESUME resume execution
* T_EXIT exit
* T_STEP set trace bit
*
* The T_OK and T_EXIT commands are handled here, and the T_RESUME and
* T_STEP commands are partially handled here and completed by the system
* task. The rest are handled entirely by the system task.
*/
#include "pm.h"
#include <minix/com.h>
#include <sys/ptrace.h>
#include <signal.h>
#include "mproc.h"
#include "param.h"
#define NIL_MPROC ((struct mproc *) 0)
FORWARD _PROTOTYPE( struct mproc *find_proc, (pid_t lpid) );
/*===========================================================================*
* do_trace *
*===========================================================================*/
PUBLIC int do_trace()
{
register struct mproc *child;
/* the T_OK call is made by the child fork of the debugger before it execs
* the process to be traced
*/
if (m_in.request == T_OK) { /* enable tracing by parent for this proc */
mp->mp_flags |= TRACED;
mp->mp_reply.reply_trace = 0;
return(OK);
}
if ((child=find_proc(m_in.pid))==NIL_MPROC || !(child->mp_flags & STOPPED)) {
return(ESRCH);
}
/* all the other calls are made by the parent fork of the debugger to
* control execution of the child
*/
switch (m_in.request) {
case T_EXIT: /* exit */
pm_exit(child, (int) m_in.data);
mp->mp_reply.reply_trace = 0;
return(OK);
case T_RESUME:
case T_STEP: /* resume execution */
if (m_in.data < 0 || m_in.data > _NSIG) return(EIO);
if (m_in.data > 0) { /* issue signal */
child->mp_flags &= ~TRACED; /* so signal is not diverted */
sig_proc(child, (int) m_in.data);
child->mp_flags |= TRACED;
}
child->mp_flags &= ~STOPPED;
break;
}
if (sys_trace(m_in.request,(int)(child-mproc),m_in.taddr,&m_in.data) != OK)
return(-errno);
mp->mp_reply.reply_trace = m_in.data;
return(OK);
}
/*===========================================================================*
* find_proc *
*===========================================================================*/
PRIVATE struct mproc *find_proc(lpid)
pid_t lpid;
{
register struct mproc *rmp;
for (rmp = &mproc[0]; rmp < &mproc[NR_PROCS]; rmp++)
if (rmp->mp_flags & IN_USE && rmp->mp_pid == lpid) return(rmp);
return(NIL_MPROC);
}
/*===========================================================================*
* stop_proc *
*===========================================================================*/
PUBLIC void stop_proc(rmp, signo)
register struct mproc *rmp;
int signo;
{
/* A traced process got a signal so stop it. */
register struct mproc *rpmp = mproc + rmp->mp_parent;
if (sys_trace(-1, (int) (rmp - mproc), 0L, (long *) 0) != OK) return;
rmp->mp_flags |= STOPPED;
if (rpmp->mp_flags & WAITING) {
rpmp->mp_flags &= ~WAITING; /* parent is no longer waiting */
rpmp->mp_reply.reply_res2 = 0177 | (signo << 8);
setreply(rmp->mp_parent, rmp->mp_pid);
} else {
rmp->mp_sigstatus = signo;
}
return;
}