209 lines
6.2 KiB
C
209 lines
6.2 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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* m_lsys_krn_sys_trace.endpt process that is traced
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* m_lsys_krn_sys_trace.request trace request
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* m_lsys_krn_sys_trace.address address at traced process' space
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* m_lsys_krn_sys_trace.data data to be written
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* m_krn_lsys_sys_trace.data data to be returned
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*/
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#include "kernel/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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int do_trace(struct proc * caller, 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 in instruction space
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* T_SETDATA set value in 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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* T_ATTACH attach to an existing process
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* T_DETACH detach from a traced process
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* T_SETOPT set trace options
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* T_GETRANGE get range of values
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* T_SETRANGE set range of values
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*
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* The T_OK, T_ATTACH, T_EXIT, and T_SETOPT commands are handled completely by
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* the process manager. T_GETRANGE and T_SETRANGE use sys_vircopy(). All others
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* come here.
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*/
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register struct proc *rp;
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vir_bytes tr_addr = m_ptr->m_lsys_krn_sys_trace.address;
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long tr_data = m_ptr->m_lsys_krn_sys_trace.data;
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int tr_request = m_ptr->m_lsys_krn_sys_trace.request;
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int tr_proc_nr_e = m_ptr->m_lsys_krn_sys_trace.endpt, tr_proc_nr;
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unsigned char ub;
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int i;
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#define COPYTOPROC(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 = KERNEL; \
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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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if((r=virtual_copy_vmcheck(caller, &fromaddr, \
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&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(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 = KERNEL; \
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fromaddr.offset = (addr); \
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toaddr.offset = (myaddr); \
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if((r=virtual_copy_vmcheck(caller, &fromaddr, \
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&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_SET(rp, RTS_P_STOP);
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/* clear syscall trace and single step flags */
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rp->p_misc_flags &= ~(MF_SC_TRACE | MF_STEP);
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return(OK);
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case T_GETINS: /* return value from instruction space */
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COPYFROMPROC(tr_addr, (vir_bytes) &tr_data, sizeof(long));
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m_ptr->m_krn_lsys_sys_trace.data = tr_data;
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break;
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case T_GETDATA: /* return value from data space */
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COPYFROMPROC(tr_addr, (vir_bytes) &tr_data, sizeof(long));
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m_ptr->m_krn_lsys_sys_trace.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(EFAULT);
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if (tr_addr <= sizeof(struct proc) - sizeof(long)) {
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m_ptr->m_krn_lsys_sys_trace.data =
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*(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(EFAULT);
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m_ptr->m_krn_lsys_sys_trace.data =
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*(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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COPYTOPROC(tr_addr, (vir_bytes) &tr_data, sizeof(long));
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m_ptr->m_krn_lsys_sys_trace.data = 0;
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break;
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case T_SETDATA: /* set value in data space */
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COPYTOPROC(tr_addr, (vir_bytes) &tr_data, sizeof(long));
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m_ptr->m_krn_lsys_sys_trace.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(EFAULT);
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i = (int) tr_addr;
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#if defined(__i386__)
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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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i == (int) &((struct proc *) 0)->p_reg.gs ||
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i == (int) &((struct proc *) 0)->p_reg.fs ||
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i == (int) &((struct proc *) 0)->p_reg.ss)
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return(EFAULT);
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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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#elif defined(__arm__)
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if (i == (int) &((struct proc *) 0)->p_reg.psr) {
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/* only selected bits are changeable */
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SET_USR_PSR(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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}
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#endif
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m_ptr->m_krn_lsys_sys_trace.data = 0;
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break;
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case T_DETACH: /* detach tracer */
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rp->p_misc_flags &= ~MF_SC_ACTIVE;
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/* fall through */
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case T_RESUME: /* resume execution */
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RTS_UNSET(rp, RTS_P_STOP);
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m_ptr->m_krn_lsys_sys_trace.data = 0;
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break;
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case T_STEP: /* set trace bit */
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rp->p_misc_flags |= MF_STEP;
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RTS_UNSET(rp, RTS_P_STOP);
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m_ptr->m_krn_lsys_sys_trace.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_UNSET(rp, RTS_P_STOP);
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m_ptr->m_krn_lsys_sys_trace.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(tr_addr, (vir_bytes) &ub, 1);
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m_ptr->m_krn_lsys_sys_trace.data = ub;
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break;
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case T_WRITEB_INS: /* set value in instruction space */
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ub = (unsigned char) (tr_data & 0xff);
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COPYTOPROC(tr_addr, (vir_bytes) &ub, 1);
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m_ptr->m_krn_lsys_sys_trace.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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