lib/libtnfctl/prb_proc.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 1994-1999 by Sun Microsystems, Inc.
 * All rights reserved.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * This file contains interfaces that are wrappers over the basic
 * /proc ioctls
 */

#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/uio.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/fault.h>
#include <sys/procfs.h>

#include "prb_proc_int.h"
#include "dbg.h"

/*
 * Declarations
 */

#define PROCFORMAT  "/proc/%d"

static prb_status_t
prb_proc_open_general(pid_t pid, prb_proc_ctl_t **proc_pp, int oflg);

/*
 * prb_proc_open_general() - function to open the process file
 * system entry for the supplied process. Opens with different
 * options based on the 'oflg'.
 * Returns a pointer to an opaque structure that contains the fd
 * needed for /proc control.
 */

prb_status_t
prb_proc_open_general(pid_t pid, prb_proc_ctl_t **proc_pp, int oflg)
{
    prb_proc_ctl_t      *proc_p;
    char            path[MAXPATHLEN];
    int         retval;

    (void) sprintf(path, PROCFORMAT, (int)pid);

    DBG_TNF_PROBE_1(prb_proc_open_1, "libtnfctl", "sunw%verbosity 2",
        tnf_string, opening_proc_on, path);

    retval = open(path, oflg);
    if (retval == -1) {
        DBG((void) fprintf(stderr,
            "proc_open: open of \"%s\" failed: %s\n",
            path, strerror(errno)));
        return (prb_status_map(errno));
    }
    /* allocate proc_p and zero fill */
    proc_p = calloc(1, sizeof (*proc_p));
    if (proc_p == NULL)
        return (PRB_STATUS_ALLOCFAIL);
    proc_p->procfd = retval;
    proc_p->pid = pid;
    *proc_pp = proc_p;
    return (PRB_STATUS_OK);
}


/*
 * prb_proc_open() - a wrapper which opens the process file system
 * entry for the supplied process.  Returns a pointer to an opaque
 * structure that contains the fd needed for /proc control.
 */

prb_status_t
prb_proc_open(pid_t pid, prb_proc_ctl_t **proc_pp)
{

    return (prb_proc_open_general(pid,
                proc_pp, O_RDWR | O_EXCL));

}

/*
 * prb_proc_reopen() - re-opens the process, mainly for setuid/setgid files.
 * Read the last section of /proc man page for details.
 * re-open should not use O_EXCL flag.
 */

prb_status_t
prb_proc_reopen(pid_t pid, prb_proc_ctl_t **proc_pp)
{

    return (prb_proc_open_general(pid,
                proc_pp, O_RDWR));

}

/*
 * prob_proc_close() - close the proc fd and free the memory taken up
 *  by proc_p
 */
prb_status_t
prb_proc_close(prb_proc_ctl_t *proc_p)
{
    DBG_TNF_PROBE_0(prb_proc_close_1, "libtnfctl", "sunw%verbosity 2");

    if (proc_p == NULL)
        return (PRB_STATUS_OK);

    if (close(proc_p->procfd) == -1) {
        DBG((void) fprintf(stderr,
            "proc_close: close failed: %s\n", strerror(errno)));
        return (prb_status_map(errno));
    }
    free(proc_p);
    return (PRB_STATUS_OK);
}

/*
 * prb_proc_pid_get() - gets the pid of the proc
 */
pid_t
prb_proc_pid_get(prb_proc_ctl_t *proc_p)
{
    return (proc_p->pid);
}

/*
 * prb_proc_stop() - stops the target process
 */
prb_status_t
prb_proc_stop(prb_proc_ctl_t *proc_p)
{
    int          retval;

    DBG_TNF_PROBE_0(prb_proc_stop_1, "libtnfctl",
        "sunw%verbosity 2; sunw%debug 'stopping the target process'");

again:
    retval = ioctl(proc_p->procfd, PIOCSTOP, NULL);
    if (retval == -1) {
        if (errno == EINTR)
            goto again;
        DBG((void) fprintf(stderr,
            "prb_proc_stop: PIOCSTOP failed: %s\n",
            strerror(errno)));
        return (prb_status_map(errno));
    }
    return (PRB_STATUS_OK);
}


/*
 * prb_proc_prstop() - runs and stops the process, used to clear a target
 * process out of a system call state.
 */
prb_status_t
prb_proc_prstop(prb_proc_ctl_t *proc_p)
{
    int     procfd;
    int     retval;
    prrun_t     prrun;
    prstatus_t  prstat;

    DBG_TNF_PROBE_0(prb_proc_prstop_1, "libtnfctl",
        "sunw%verbosity 2; sunw%debug 'stepping the target process'");

    procfd = proc_p->procfd;
    (void) memset((char *)&prrun, 0, sizeof (prrun));
    (void) memset((char *)&prstat, 0, sizeof (prstat));

again1:
    prrun.pr_flags = PRSTOP;
    retval = ioctl(procfd, PIOCRUN, &prrun);
    if (retval == -1) {
        if (errno == EINTR)
            goto again1;
        DBG((void) fprintf(stderr,
            "prb_proc_prstop: PIOCRUN failed: %s\n",
            strerror(errno)));
        return (prb_status_map(errno));
    }
again2:
    retval = ioctl(procfd, PIOCWSTOP, &prstat);
    if (retval == -1) {
        if (errno == EINTR)
            goto again2;
        DBG((void) fprintf(stderr,
            "prb_proc_prstop: PIOCWSTOP failed: %s\n",
            strerror(errno)));
        return (prb_status_map(errno));
    }
    /*
     * if we didn't stop because we requested it (eg. if there was a
     * signal in the target ?), we might need to try again
     */
    if (prstat.pr_why != PR_REQUESTED)
        goto again1;

    return (PRB_STATUS_OK);
}


/*
 * prb_proc_state() - returns the status pf the process
 */
prb_status_t
prb_proc_state(prb_proc_ctl_t *proc_p, prb_proc_state_t *state_p)
{
    int     procfd;
    int     retval;
    prstatus_t  prstatus;

    DBG_TNF_PROBE_0(prb_proc_state_1, "libtnfctl",
        "sunw%verbosity 2; sunw%debug 'getting the status'");

    procfd = proc_p->procfd;

    (void) memset(&prstatus, 0, sizeof (prstatus));

again:
    retval = ioctl(procfd, PIOCSTATUS, &prstatus);
    if (retval == -1) {
        if (errno == EINTR)
            goto again;
        DBG((void) fprintf(stderr,
            "prb_proc_status: PIOCSTATUS failed: %s\n",
            strerror(errno)));
        return (prb_status_map(errno));
    }
    state_p->ps_isbptfault = (prstatus.pr_flags & PR_FAULTED &&
        prstatus.pr_what == FLTBPT);
    state_p->ps_isstopped = ((prstatus.pr_flags & PR_STOPPED) != 0);
    state_p->ps_isinsys = ((prstatus.pr_flags & PR_ASLEEP) != 0);
    state_p->ps_isrequested = ((prstatus.pr_why & PR_REQUESTED) != 0);
    state_p->ps_issysexit = ((prstatus.pr_why & PR_SYSEXIT) != 0);
    state_p->ps_issysentry = ((prstatus.pr_why & PR_SYSENTRY) != 0);
    state_p->ps_syscallnum = prstatus.pr_what;
    return (PRB_STATUS_OK);
}


/*
 * prb_proc_wait() - waits for the target process to stop
 */
prb_status_t
prb_proc_wait(prb_proc_ctl_t *proc_p, boolean_t use_sigmask, sigset_t *oldmask)
{
    int     procfd;
    int     retval;
    prstatus_t  prstat;
    sigset_t    pendmask;
    int     i, mask_size;
    boolean_t   pending_signal = B_FALSE;

    DBG_TNF_PROBE_0(prb_proc_wait_1, "libtnfctl",
        "sunw%verbosity 2;"
        "sunw%debug 'waiting for the target process to stop'");

    procfd = proc_p->procfd;

    /*
     * This one of the places where we do not resubmit the ioctl if
     * if it is terminated by an EINTR (interrupted system call). In
     * this case, the caller knows best ...
     */
    (void) memset(&prstat, 0, sizeof (prstat));

    /* if we blocked signals... */
    if (use_sigmask) {
        if (sigemptyset(&pendmask) == -1)
            return (prb_status_map(errno));
        if (sigpending(&pendmask) == -1)
            return (prb_status_map(errno));
        /*
         * check if there were any signals pending -
         * XXXX libc should provide this interface
         */
        mask_size = sizeof (pendmask) / sizeof (pendmask.__sigbits[0]);
        for (i = 0; i < mask_size; i++) {
            if (pendmask.__sigbits[i] != 0)
                pending_signal = B_TRUE;
        }

        /* return to original signal mask */
        if (sigprocmask(SIG_SETMASK, oldmask, NULL) == -1)
            return (prb_status_map(errno));

        /* if there was a pending signal, don't call PIOCWSTOP ioctl */
        if (pending_signal)
            return (prb_status_map(EINTR));

        /*
         * XXXX - there is a a race between now and when we call
         * the PIOCWSTOP ioctl.  One solution, is for the user to
         * call an interface in libtnfctl from their signal handler.
         * This interface will do a longjmp such that it never
         * calls the ioctl (the setjmp would be before we restore
         * the signal mask above)
         */
    }

    retval = ioctl(procfd, PIOCWSTOP, &prstat);

    DBG_TNF_PROBE_2(prb_proc_wait_2, "libtnfctl", "sunw%verbosity 2;",
            tnf_opaque, pc, prstat.pr_reg[R_PC],
            tnf_opaque, instr, prstat.pr_instr);

    if (retval == -1) {
#ifdef DEBUG
        if (errno != EINTR && errno != ENOENT)
            (void) fprintf(stderr,
                "prb_proc_wait: PIOCWSTOP failed: %s\n",
                strerror(errno));

#endif
        return (prb_status_map(errno));
    }

    return (PRB_STATUS_OK);
}


/*
 * prb_proc_cont() - continues the target process
 */
prb_status_t
prb_proc_cont(prb_proc_ctl_t *proc_p)
{
    int     procfd;
    int     retval;
    prrun_t     prrun;

    DBG_TNF_PROBE_0(prb_proc_cont_1, "libtnfctl",
        "sunw%verbosity 2; sunw%debug 'starting the target process'");
    procfd = proc_p->procfd;

    (void) memset((char *)&prrun, 0, sizeof (prrun));

again:
    prrun.pr_flags = PRCFAULT;
    retval = ioctl(procfd, PIOCRUN, &prrun);
    if (retval == -1) {
        if (errno == EINTR)
            goto again;
        DBG((void) fprintf(stderr,
            "prb_proc_cont: PIOCRUN failed: %s\n",
            strerror(errno)));
        return (prb_status_map(errno));
    }
    return (PRB_STATUS_OK);
}


/*
 * prb_proc_istepbpt() - step the target process one instruction
 *
 * CAUTION!!!! - this routine is specialized to only be able to single
 * step over the breakpoint location.
 */
prb_status_t
prb_proc_istepbpt(prb_proc_ctl_t *proc_p)
{
    int     procfd;
    int     retval;
    prrun_t     run;
    fltset_t    faults;
    prstatus_t  prstat;

    DBG_TNF_PROBE_0(prb_proc_istepbpt_1, "libtnfctl",
        "sunw%verbosity 2; "
        "sunw%debug 'single stepping over breakpoint'");

    procfd = proc_p->procfd;

    (void) memset((char *)&run, 0, sizeof (run));

    /* add trace fault to the list of current traced faults */
again1:
    retval = ioctl(procfd, PIOCGFAULT, &faults);
    if (retval == -1) {
        if (errno == EINTR)
            goto again1;
        DBG((void) fprintf(stderr,
            "prb_proc_istepbpt: PIOCGFAULT failed: %s\n",
            strerror(errno)));
        return (prb_status_map(errno));
    }
    praddset(&faults, FLTTRACE);

    /* issue the run command with the single-step option */
    run.pr_flags = PRCFAULT | PRSFAULT | PRSTEP;
    run.pr_fault = faults;

    /* load the location of the breakpoint */
    run.pr_vaddr = (caddr_t)proc_p->bptaddr;
    run.pr_flags |= PRSVADDR;

again2:
    retval = ioctl(procfd, PIOCRUN, &run);
    if (retval == -1) {
        if (errno == EINTR)
            goto again2;
        DBG((void) fprintf(stderr,
            "prb_proc_istepbpt: PIOCRUN failed: %s\n",
            strerror(errno)));
        return (prb_status_map(errno));
    }
again3:
    retval = ioctl(procfd, PIOCWSTOP, &prstat);
    if (retval == -1) {
        if (errno == EINTR)
            goto again3;
        DBG((void) fprintf(stderr,
                "prb_proc_istepbpt: PIOCWSTOP failed: %s\n",
                strerror(errno)));
        return (prb_status_map(errno));
    }

    DBG_TNF_PROBE_2(prb_proc_istepbpt_2, "libtnfctl", "sunw%verbosity 2;",
            tnf_opaque, pc, prstat.pr_reg[R_PC],
            tnf_opaque, instr, prstat.pr_instr);


    /* clear any current faults */
again4:
    retval = ioctl(procfd, PIOCCFAULT, NULL);
    if (retval == -1) {
        if (errno == EINTR)
            goto again4;
        DBG((void) fprintf(stderr,
            "prb_proc_clrbptflt: PIOCCFAULT failed: %s\n",
            strerror(errno)));
        return (prb_status_map(errno));
    }
    /* remove the trace fault from the current traced faults */
    prdelset(&faults, FLTTRACE);
again5:
    retval = ioctl(procfd, PIOCSFAULT, &faults);
    if (retval == -1) {
        if (errno == EINTR)
            goto again5;
        DBG((void) fprintf(stderr,
            "prb_proc_istepbpt: PIOCSFAULT failed: %s\n",
            strerror(errno)));
        return (prb_status_map(errno));
    }
    return (PRB_STATUS_OK);
}


/*
 * prb_proc_clrbptflt() - clear an encountered breakpoint fault
 */
prb_status_t
prb_proc_clrbptflt(prb_proc_ctl_t *proc_p)
{
    int retval;
    int procfd;

    DBG_TNF_PROBE_0(prb_proc_clrbptflt_1, "libtnfctl", "sunw%verbosity 2");

    procfd = proc_p->procfd;

    /* clear any current faults */
again:
    retval = ioctl(procfd, PIOCCFAULT, NULL);
    if (retval == -1) {
        if (errno == EINTR)
            goto again;
        DBG((void) fprintf(stderr,
            "prb_proc_clrbptflt: PIOCCFAULT failed: %s\n",
            strerror(errno)));
        return (prb_status_map(errno));
    }
    return (PRB_STATUS_OK);
}


/*
 * prb_proc_tracebpt() - sets the bpt tracing state.
 */
prb_status_t
prb_proc_tracebpt(prb_proc_ctl_t *proc_p, boolean_t bpt)
{
    int     procfd;
    int     retval;
    fltset_t    faults;

    DBG_TNF_PROBE_1(prb_proc_tracebpt_1, "libtnfctl", "sunw%verbosity 2;",
        tnf_string, bpt_state, (bpt) ? "enabled" : "disabled");

    procfd = proc_p->procfd;
    /* get the current set of traced faults */
again1:
    retval = ioctl(procfd, PIOCGFAULT, &faults);
    if (retval == -1) {
        if (errno == EINTR)
            goto again1;
        DBG((void) fprintf(stderr,
            "prb_proc_tracebpt: PIOCGFAULT failed: %s\n",
            strerror(errno)));
        return (prb_status_map(errno));
    }
    /* set or clear the breakpoint flag */
    if (bpt)
        praddset(&faults, FLTBPT);
    else
        prdelset(&faults, FLTBPT);

    /* write the fault set back */
again2:
    retval = ioctl(procfd, PIOCSFAULT, &faults);
    if (retval == -1) {
        if (errno == EINTR)
            goto again2;
        DBG((void) fprintf(stderr,
            "prb_proc_tracebpt: PIOCSFAULT failed: %s\n",
            strerror(errno)));
        return (prb_status_map(errno));
    }
    return (PRB_STATUS_OK);
}

/* Note - the following 3 functions should be combined */

/*
 * prb_proc_setrlc() - sets or clears the run-on-last-close flag.
 */
prb_status_t
prb_proc_setrlc(prb_proc_ctl_t *proc_p, boolean_t rlc)
{
    int         procfd;
    long            mode;
    int         retval;

    DBG_TNF_PROBE_1(prb_proc_setrlc_1, "libtnfctl", "sunw%verbosity 2;",
        tnf_string, run_on_last_close, (rlc) ? "setting" : "clearing");

    procfd = proc_p->procfd;
    mode = PR_RLC;

    if (rlc) {
again1:
        retval = ioctl(procfd, PIOCSET, &mode);
        if (retval == -1) {
            if (errno == EINTR)
                goto again1;
            DBG((void) fprintf(stderr,
                "prb_proc_setrlc: PIOCSET failed: %s\n",
                strerror(errno)));
            return (prb_status_map(errno));
        }
    } else {
again2:
        retval = ioctl(procfd, PIOCRESET, &mode);
        if (retval == -1) {
            if (errno == EINTR)
                goto again2;
            DBG((void) fprintf(stderr,
                "prb_proc_setrlc: PIOCRESET failed: %s\n",
                strerror(errno)));
            return (prb_status_map(errno));
        }
    }

    return (PRB_STATUS_OK);


}               /* end prb_proc_setrlc */


/*
 * prb_proc_setklc() - sets or clears the kill-on-last-close flag.
 */
prb_status_t
prb_proc_setklc(prb_proc_ctl_t *proc_p, boolean_t klc)
{
    int         procfd;
    long            mode;
    int         retval;

    DBG_TNF_PROBE_1(prb_proc_setklc_1, "libtnfctl", "sunw%verbosity 2;",
        tnf_string, kill_on_last_close, (klc) ? "setting" : "clearing");

    procfd = proc_p->procfd;
    mode = PR_KLC;

    if (klc) {
again1:
        retval = ioctl(procfd, PIOCSET, &mode);
        if (retval == -1) {
            if (errno == EINTR)
                goto again1;
            DBG((void) fprintf(stderr,
                "prb_proc_setklc: PIOCSET failed: %s\n",
                strerror(errno)));
            return (prb_status_map(errno));
        }
    } else {
again2:
        retval = ioctl(procfd, PIOCRESET, &mode);
        if (retval == -1) {
            if (errno == EINTR)
                goto again2;
            DBG((void) fprintf(stderr,
                "prb_proc_setklc: PIOCRESET failed: %s\n",
                strerror(errno)));
            return (prb_status_map(errno));
        }
    }

    return (PRB_STATUS_OK);

}               /* end prb_proc_setklc */

/*
 * prb_proc_setfork() - sets or clears the inherit-on-fork flag
 */
prb_status_t
prb_proc_setfork(prb_proc_ctl_t *proc_p, boolean_t inhfork)
{
    int         procfd;
    long            mode;
    int         retval;

    DBG_TNF_PROBE_1(prb_proc_setfork_1, "libtnfctl", "sunw%verbosity 2;",
        tnf_string, kill_on_last_close,
        (inhfork) ? "setting" : "clearing");

    procfd = proc_p->procfd;
    mode = PR_FORK;

    if (inhfork) {
again1:
        retval = ioctl(procfd, PIOCSET, &mode);
        if (retval == -1) {
            if (errno == EINTR)
                goto again1;
            DBG((void) fprintf(stderr,
                "prb_proc_setfork: PIOCSET failed: %s\n",
                strerror(errno)));
            return (prb_status_map(errno));
        }
    } else {
again2:
        retval = ioctl(procfd, PIOCRESET, &mode);
        if (retval == -1) {
            if (errno == EINTR)
                goto again2;
            DBG((void) fprintf(stderr,
                "prb_proc_setfork: PIOCRESET failed: %s\n",
                strerror(errno)));
            return (prb_status_map(errno));
        }
    }

    return (PRB_STATUS_OK);

}               /* end prb_proc_setfork */

/*
 * prb_proc_exit() - if op is PRB_SYS_ALL, sets up the target process to stop
 * on exit from all system calls.  If op is PRB_SYS_NONE, sets up the target
 * process so that it will not stop on exit from any system call.
 * PRB_SYS_ADD and PRB_SYS_DEL adds or deletes a particular system call from
 * the mask of "interested" system calls respectively. This function can be
 * called multiple times to build up the mask.
 */
prb_status_t
prb_proc_exit(prb_proc_ctl_t *proc_p,
    uint_t syscall,
    prb_syscall_op_t op)
{
    int     procfd;
    int     retval;
    sysset_t    sysmask;

    DBG_TNF_PROBE_0(prb_proc_exit_1, "libtnfctl",
        "sunw%verbosity 2; "
        "sunw%debug 'setting up target to stop on exit of syscall'");

    procfd = proc_p->procfd;

    switch (op) {
    case PRB_SYS_ALL:
        prfillset(&sysmask);
        break;
    case PRB_SYS_NONE:
        premptyset(&sysmask);
        break;
    case PRB_SYS_ADD:
again1:
        retval = ioctl(procfd, PIOCGEXIT, &sysmask);
        if (retval == -1) {
            if (errno == EINTR)
                goto again1;
            DBG((void) fprintf(stderr,
                "prb_proc_exit: PIOCGEXIT failed: %s\n",
                strerror(errno)));
            return (prb_status_map(errno));
        }
        praddset(&sysmask, syscall);
        break;
    case PRB_SYS_DEL:
again2:
        retval = ioctl(procfd, PIOCGEXIT, &sysmask);
        if (retval == -1) {
            if (errno == EINTR)
                goto again2;
            DBG((void) fprintf(stderr,
                "prb_proc_exit: PIOCGEXIT failed: %s\n",
                strerror(errno)));
            return (prb_status_map(errno));
        }
        prdelset(&sysmask, syscall);
        break;
    default:
        DBG((void) fprintf(stderr, "prb_proc_exit: bad input arg\n"));
        return (PRB_STATUS_BADARG);
    }
again3:
    retval = ioctl(procfd, PIOCSEXIT, &sysmask);
    if (retval == -1) {
        if (errno == EINTR)
            goto again3;
        DBG((void) fprintf(stderr,
            "prb_proc_exit: PIOCSEXIT failed: %s\n",
            strerror(errno)));
        return (prb_status_map(errno));
    }
    return (PRB_STATUS_OK);

}               /* end prb_proc_exit */

/*
 * prb_proc_entry() - if op is PRB_SYS_ALL, sets up the target process to
 * stop on entry from all system calls.  If op is PRB_SYS_NONE, sets up the
 * target process so that it will not stop on entry from any system call.
 * PRB_SYS_ADD and PRB_SYS_DEL adds or deletes a particular system call from
 * the mask of "interested" system calls respectively. This function can be
 * called multiple times to build up the mask.
 */
prb_status_t
prb_proc_entry(prb_proc_ctl_t *proc_p,
    uint_t syscall,
    prb_syscall_op_t op)
{
    int     procfd;
    int     retval;
    sysset_t    sysmask;

    DBG_TNF_PROBE_0(prb_proc_entry_1, "libtnfctl",
        "sunw%verbosity 2; "
        "sunw%debug 'setting up target to stop on entry of syscall'");

    procfd = proc_p->procfd;

    switch (op) {
    case PRB_SYS_ALL:
        prfillset(&sysmask);
        break;
    case PRB_SYS_NONE:
        premptyset(&sysmask);
        break;
    case PRB_SYS_ADD:
again1:
        retval = ioctl(procfd, PIOCGENTRY, &sysmask);
        if (retval == -1) {
            if (errno == EINTR)
                goto again1;
            DBG((void) fprintf(stderr,
                "prb_proc_entry: PIOCGENTRY failed: %s\n",
                strerror(errno)));
            return (prb_status_map(errno));
        }
        praddset(&sysmask, syscall);
        break;
    case PRB_SYS_DEL:
again2:
        retval = ioctl(procfd, PIOCGENTRY, &sysmask);
        if (retval == -1) {
            if (errno == EINTR)
                goto again2;
            DBG((void) fprintf(stderr,
                "prb_proc_entry: PIOCGENTRY failed: %s\n",
                strerror(errno)));
            return (prb_status_map(errno));
        }
        prdelset(&sysmask, syscall);
        break;
    default:
        DBG((void) fprintf(stderr, "prb_proc_entry: bad input arg\n"));
        return (PRB_STATUS_BADARG);
    }
again3:
    retval = ioctl(procfd, PIOCSENTRY, &sysmask);
    if (retval == -1) {
        if (errno == EINTR)
            goto again3;
        DBG((void) fprintf(stderr,
            "prb_proc_entry: PIOCSENTRY failed: %s\n",
            strerror(errno)));
        return (prb_status_map(errno));
    }
    return (PRB_STATUS_OK);
}

/*
 * prb_proc_read() - reads a block of memory from a processes address space.
 */
prb_status_t
prb_proc_read(prb_proc_ctl_t *proc_p, uintptr_t addr, void *buf, size_t size)
{
    int     procfd;
    ssize_t     sz;
    off_t       offset;

    DBG_TNF_PROBE_2(prb_proc_read_1, "libtnfctl", "sunw%verbosity 3;",
        tnf_long, num_bytes, size,
        tnf_opaque, from_address, addr);

    procfd = proc_p->procfd;
    offset = lseek(procfd, (off_t)addr, SEEK_SET);
    if (offset != (off_t)addr) {
        DBG(perror("prb_proc_read: lseek failed"));
        return (prb_status_map(errno));
    }
    sz = read(procfd, buf, size);
    if (sz != size) {
        DBG(perror("prb_proc_read: read failed"));
        return (prb_status_map(errno));
    }
    return (PRB_STATUS_OK);
}


/*
 * prb_proc_write() - writes a block of memory from a processes address
 * space.
 */
prb_status_t
prb_proc_write(prb_proc_ctl_t *proc_p, uintptr_t addr, void *buf, size_t size)
{
    int     procfd;
    ssize_t     sz;
    off_t       offset;

    DBG_TNF_PROBE_2(prb_proc_write_1, "libtnfctl", "sunw%verbosity 3;",
        tnf_long, num_bytes, size,
        tnf_opaque, to_address, addr);

    procfd = proc_p->procfd;
    offset = lseek(procfd, (off_t)addr, SEEK_SET);
    if (offset != (off_t)addr) {
        DBG(perror("prb_proc_write: lseek failed"));
        return (prb_status_map(errno));
    }
    sz = write(procfd, buf, size);
    if (sz != size) {
        DBG(perror("prb_proc_write: write failed"));
        return (prb_status_map(errno));
    }
    return (PRB_STATUS_OK);
}


/*
 * prb_proc_readstr() - dereferences a string in the target
 *  NOTE: There is a similar routine called _tnfctl_readstr_targ()
 *        used by tnfctl layer.  It would be better if there was only
 *        one of these functions defined.
 */

#define BUFSZ   256

prb_status_t
prb_proc_readstr(prb_proc_ctl_t *proc_p, uintptr_t addr, const char **outstr_pp)
{
    prb_status_t    prbstat;
    int     bufsz = BUFSZ;
    char        buffer[BUFSZ + 1];
    offset_t    offset;
    char        *ptr, *orig_ptr;

    *outstr_pp = NULL;
    offset = 0;

    /* allocate an inital return buffer */
    ptr = (char *)malloc(BUFSZ);
    if (!ptr) {
        DBG((void) fprintf(stderr,
            "prb_proc_readstr: malloc failed\n"));
        return (PRB_STATUS_ALLOCFAIL);
    }
    /*LINTED constant in conditional context*/
    while (1) {
        int          i;

        /* read a chunk into our buffer */
        prbstat = prb_proc_read(proc_p, addr + offset, buffer, bufsz);
        if (prbstat) {

            /*
             * if we get into trouble with a large read, try again
             * with a single byte.  Subsequent failure is real ...
             */
            if (bufsz > 1) {
                bufsz = 1;
                continue;
            }

            DBG((void) fprintf(stderr,
                "prb_proc_readstr: prb_proc_read failed: %s\n",
                prb_status_str(prbstat)));
            free(ptr);
            return (prbstat);
        }
        /* copy the chracters into the return buffer */
        for (i = 0; i < bufsz; i++) {
            char            c = buffer[i];

            ptr[offset + i] = c;
            if (c == '\0') {
                /* hooray! we saw the end of the string */
                *outstr_pp = ptr;
                return (PRB_STATUS_OK);
            }
        }

        /* bummer, need to grab another bufsz characters */
        offset += bufsz;
        orig_ptr = ptr;
        ptr = (char *)realloc(ptr, offset + bufsz);
        if (!ptr) {
            free(orig_ptr);
            DBG((void) fprintf(stderr,
                "prb_proc_readstr: realloc failed\n"));
            return (PRB_STATUS_ALLOCFAIL);
        }
    }

#if defined(lint)
    return (PRB_STATUS_OK);
#endif
}

prb_status_t
prb_proc_get_r0_r1(prb_proc_ctl_t *proc_p, prgreg_t *r0, prgreg_t *r1)
{
    int retval;
    int procfd;
    prstatus_t  prstatus;

    procfd = proc_p->procfd;
again:
    retval = ioctl(procfd, PIOCSTATUS, &prstatus);
    if (retval == -1) {
        if (errno == EINTR)
            goto again;
        return (prb_status_map(errno));
    }

    /*
     *  Use R_Rn register definitions for some uniformity
     *     sparc:   define R_R0  R_O0
     *          define R_R1  R_O1
     *     x86:     define R_R0  EAX
     *          define R_R1  EDX
     */
    *r0 = prstatus.pr_reg[R_R0];
    *r1 = prstatus.pr_reg[R_R1];
    DBG((void) fprintf
        (stderr, "prb_proc_get_r0_r1: R_R0 = %d, R_R1 = %d\n", *r0, *r1));
    return (PRB_STATUS_OK);
}