b423d7b477
o Support for ptrace T_ATTACH/T_DETACH and T_SYSCALL o PM signal handling logic should now work properly, even with debuggers being present o Asynchronous PM/VFS protocol, full IPC support for senda(), and AMF_NOREPLY senda() flag DETAILS Process stop and delay call handling of PM: o Added sys_runctl() kernel call with sys_stop() and sys_resume() aliases, for PM to stop and resume a process o Added exception for sending/syscall-traced processes to sys_runctl(), and matching SIGKREADY pseudo-signal to PM o Fixed PM signal logic to deal with requests from a process after stopping it (so-called "delay calls"), using the SIGKREADY facility o Fixed various PM panics due to race conditions with delay calls versus VFS calls o Removed special PRIO_STOP priority value o Added SYS_LOCK RTS kernel flag, to stop an individual process from running while modifying its process structure Signal and debugger handling in PM: o Fixed debugger signals being dropped if a second signal arrives when the debugger has not retrieved the first one o Fixed debugger signals being sent to the debugger more than once o Fixed debugger signals unpausing process in VFS; removed PM_UNPAUSE_TR protocol message o Detached debugger signals from general signal logic and from being blocked on VFS calls, meaning that even VFS can now be traced o Fixed debugger being unable to receive more than one pending signal in one process stop o Fixed signal delivery being delayed needlessly when multiple signals are pending o Fixed wait test for tracer, which was returning for children that were not waited for o Removed second parallel pending call from PM to VFS for any process o Fixed process becoming runnable between exec() and debugger trap o Added support for notifying the debugger before the parent when a debugged child exits o Fixed debugger death causing child to remain stopped forever o Fixed consistently incorrect use of _NSIG Extensions to ptrace(): o Added T_ATTACH and T_DETACH ptrace request, to attach and detach a debugger to and from a process o Added T_SYSCALL ptrace request, to trace system calls o Added T_SETOPT ptrace request, to set trace options o Added TO_TRACEFORK trace option, to attach automatically to children of a traced process o Added TO_ALTEXEC trace option, to send SIGSTOP instead of SIGTRAP upon a successful exec() of the tracee o Extended T_GETUSER ptrace support to allow retrieving a process's priv structure o Removed T_STOP ptrace request again, as it does not help implementing debuggers properly o Added MINIX3-specific ptrace test (test42) o Added proper manual page for ptrace(2) Asynchronous PM/VFS interface: o Fixed asynchronous messages not being checked when receive() is called with an endpoint other than ANY o Added AMF_NOREPLY senda() flag, preventing such messages from satisfying the receive part of a sendrec() o Added asynsend3() that takes optional flags; asynsend() is now a #define passing in 0 as third parameter o Made PM/VFS protocol asynchronous; reintroduced tell_fs() o Made PM_BASE request/reply number range unique o Hacked in a horrible temporary workaround into RS to deal with newly revealed RS-PM-VFS race condition triangle until VFS is asynchronous System signal handling: o Fixed shutdown logic of device drivers; removed old SIGKSTOP signal o Removed is-superuser check from PM's do_procstat() (aka getsigset()) o Added sigset macros to allow system processes to deal with the full signal set, rather than just the POSIX subset Miscellaneous PM fixes: o Split do_getset into do_get and do_set, merging common code and making structure clearer o Fixed setpriority() being able to put to sleep processes using an invalid parameter, or revive zombie processes o Made find_proc() global; removed obsolete proc_from_pid() o Cleanup here and there Also included: o Fixed false-positive boot order kernel warning o Removed last traces of old NOTIFY_FROM code THINGS OF POSSIBLE INTEREST o It should now be possible to run PM at any priority, even lower than user processes o No assumptions are made about communication speed between PM and VFS, although communication must be FIFO o A debugger will now receive incoming debuggee signals at kill time only; the process may not yet be fully stopped o A first step has been made towards making the SYSTEM task preemptible
199 lines
5.8 KiB
C
199 lines
5.8 KiB
C
/* The kernel call implemented in this file:
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* m_type: SYS_TRACE
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*
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* The parameters for this kernel call are:
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* m2_i1: CTL_ENDPT process that is traced
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* m2_i2: CTL_REQUEST trace request
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* m2_l1: CTL_ADDRESS address at traced process' space
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* m2_l2: CTL_DATA data to be written or returned here
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*/
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#include "../system.h"
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#include <sys/ptrace.h>
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#if USE_TRACE
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/*==========================================================================*
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* do_trace *
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*==========================================================================*/
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#define TR_VLSIZE ((vir_bytes) sizeof(long))
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PUBLIC int do_trace(m_ptr)
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register message *m_ptr;
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{
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/* Handle the debugging commands supported by the ptrace system call
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* The commands are:
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* T_STOP stop the process
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* T_OK enable tracing by parent for this process
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* T_GETINS return value from instruction space
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* T_GETDATA return value from data space
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* T_GETUSER return value from user process table
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* T_SETINS set value from instruction space
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* T_SETDATA set value from data space
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* T_SETUSER set value in user process table
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* T_RESUME resume execution
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* T_EXIT exit
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* T_STEP set trace bit
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* T_SYSCALL trace system call
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*
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* The T_OK and T_EXIT commands are handled completely by the process manager,
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* all others come here.
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*/
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register struct proc *rp;
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vir_bytes tr_addr = (vir_bytes) m_ptr->CTL_ADDRESS;
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long tr_data = m_ptr->CTL_DATA;
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int tr_request = m_ptr->CTL_REQUEST;
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int tr_proc_nr_e = m_ptr->CTL_ENDPT, tr_proc_nr;
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unsigned char ub;
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int i;
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#define COPYTOPROC(seg, addr, myaddr, length) { \
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struct vir_addr fromaddr, toaddr; \
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int r; \
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fromaddr.proc_nr_e = SYSTEM; \
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toaddr.proc_nr_e = tr_proc_nr_e; \
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fromaddr.offset = (myaddr); \
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toaddr.offset = (addr); \
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fromaddr.segment = D; \
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toaddr.segment = (seg); \
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if((r=virtual_copy_vmcheck(&fromaddr, &toaddr, length)) != OK) { \
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printf("Can't copy in sys_trace: %d\n", r);\
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return r;\
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} \
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}
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#define COPYFROMPROC(seg, addr, myaddr, length) { \
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struct vir_addr fromaddr, toaddr; \
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int r; \
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fromaddr.proc_nr_e = tr_proc_nr_e; \
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toaddr.proc_nr_e = SYSTEM; \
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fromaddr.offset = (addr); \
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toaddr.offset = (myaddr); \
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fromaddr.segment = (seg); \
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toaddr.segment = D; \
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if((r=virtual_copy_vmcheck(&fromaddr, &toaddr, length)) != OK) { \
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printf("Can't copy in sys_trace: %d\n", r);\
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return r;\
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} \
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}
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if(!isokendpt(tr_proc_nr_e, &tr_proc_nr)) return(EINVAL);
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if (iskerneln(tr_proc_nr)) return(EPERM);
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rp = proc_addr(tr_proc_nr);
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if (isemptyp(rp)) return(EINVAL);
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switch (tr_request) {
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case T_STOP: /* stop process */
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RTS_LOCK_SET(rp, P_STOP);
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rp->p_reg.psw &= ~TRACEBIT; /* clear trace bit */
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rp->p_misc_flags &= ~MF_SC_TRACE; /* clear syscall trace flag */
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return(OK);
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case T_GETINS: /* return value from instruction space */
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if (rp->p_memmap[T].mem_len != 0) {
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COPYFROMPROC(T, tr_addr, (vir_bytes) &tr_data, sizeof(long));
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m_ptr->CTL_DATA = tr_data;
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break;
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}
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/* Text space is actually data space - fall through. */
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case T_GETDATA: /* return value from data space */
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COPYFROMPROC(D, tr_addr, (vir_bytes) &tr_data, sizeof(long));
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m_ptr->CTL_DATA= tr_data;
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break;
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case T_GETUSER: /* return value from process table */
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if ((tr_addr & (sizeof(long) - 1)) != 0) return(EIO);
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if (tr_addr <= sizeof(struct proc) - sizeof(long)) {
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m_ptr->CTL_DATA = *(long *) ((char *) rp + (int) tr_addr);
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break;
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}
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/* The process's proc struct is followed by its priv struct.
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* The alignment here should be unnecessary, but better safe..
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*/
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i = sizeof(long) - 1;
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tr_addr -= (sizeof(struct proc) + i) & ~i;
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if (tr_addr > sizeof(struct priv) - sizeof(long)) return(EIO);
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m_ptr->CTL_DATA = *(long *) ((char *) rp->p_priv + (int) tr_addr);
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break;
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case T_SETINS: /* set value in instruction space */
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if (rp->p_memmap[T].mem_len != 0) {
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COPYTOPROC(T, tr_addr, (vir_bytes) &tr_data, sizeof(long));
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m_ptr->CTL_DATA = 0;
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break;
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}
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/* Text space is actually data space - fall through. */
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case T_SETDATA: /* set value in data space */
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COPYTOPROC(D, tr_addr, (vir_bytes) &tr_data, sizeof(long));
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m_ptr->CTL_DATA = 0;
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break;
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case T_SETUSER: /* set value in process table */
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if ((tr_addr & (sizeof(reg_t) - 1)) != 0 ||
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tr_addr > sizeof(struct stackframe_s) - sizeof(reg_t))
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return(EIO);
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i = (int) tr_addr;
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#if (_MINIX_CHIP == _CHIP_INTEL)
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/* Altering segment registers might crash the kernel when it
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* tries to load them prior to restarting a process, so do
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* not allow it.
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*/
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if (i == (int) &((struct proc *) 0)->p_reg.cs ||
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i == (int) &((struct proc *) 0)->p_reg.ds ||
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i == (int) &((struct proc *) 0)->p_reg.es ||
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#if _WORD_SIZE == 4
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i == (int) &((struct proc *) 0)->p_reg.gs ||
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i == (int) &((struct proc *) 0)->p_reg.fs ||
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#endif
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i == (int) &((struct proc *) 0)->p_reg.ss)
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return(EIO);
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#endif
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if (i == (int) &((struct proc *) 0)->p_reg.psw)
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/* only selected bits are changeable */
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SETPSW(rp, tr_data);
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else
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*(reg_t *) ((char *) &rp->p_reg + i) = (reg_t) tr_data;
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m_ptr->CTL_DATA = 0;
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break;
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case T_RESUME: /* resume execution */
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RTS_LOCK_UNSET(rp, P_STOP);
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m_ptr->CTL_DATA = 0;
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break;
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case T_STEP: /* set trace bit */
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rp->p_reg.psw |= TRACEBIT;
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RTS_LOCK_UNSET(rp, P_STOP);
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m_ptr->CTL_DATA = 0;
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break;
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case T_SYSCALL: /* trace system call */
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rp->p_misc_flags |= MF_SC_TRACE;
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RTS_LOCK_UNSET(rp, P_STOP);
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m_ptr->CTL_DATA = 0;
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break;
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case T_READB_INS: /* get value from instruction space */
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COPYFROMPROC(rp->p_memmap[T].mem_len > 0 ? T : D, tr_addr, (vir_bytes) &ub, 1);
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m_ptr->CTL_DATA = ub;
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break;
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case T_WRITEB_INS: /* set value in instruction space */
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COPYTOPROC(rp->p_memmap[T].mem_len > 0 ? T : D,tr_addr, (vir_bytes) &tr_data, 1);
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m_ptr->CTL_DATA = 0;
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break;
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default:
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return(EINVAL);
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}
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return(OK);
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}
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#endif /* USE_TRACE */
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