usr/src/sys.386bsd/kern/sys_process.c

/*
 * Copyright (c) 1982, 1986, 1989 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      from: @(#)sys_process.c 7.22 (Berkeley) 5/11/91
 */

#define IPCREG
#include "param.h"
#include "proc.h"
#include "vnode.h"
#include "buf.h"
#include "ptrace.h"

#include "machine/reg.h"
#include "machine/psl.h"
#include "vm/vm.h"
#include "vm/vm_page.h"

#include "user.h"

/*
 * NOTES.
 *
 * The following ptrace calls have been defined in addition to
 * the standard ones found in original <sys/ptrace.h>:
 *
 * PT_ATTACH            -       attach to running process
 * PT_DETACH            -       detach from running process
 * PT_SYSCALL           -       trace system calls
 * PT_GETREG            -       get register file
 * PT_SETREG            -       set register file
 * PT_BREAD_[IDU]       -       block read from process (not yet implemented)
 * PT_BWRITE_[IDU]      -       block write     "               "
 * PT_INHERIT           -       make forked processes inherit trace flags
 *
 */

/* Define to prevent extraneous clutter in source */
#ifndef SSTRC
#define SSTRC   0
#endif
#ifndef SFTRC
#define SFTRC   0
#endif

/*
 * `ipcreg' defined in <machine/reg.h>
 * Should we define a structure with all regs?
 */
int sipcreg[NIPCREG] =
  { 0,0,sEDI,sESI,sEBP,sEBX,sEDX,sECX,sEAX,sEIP,sCS,sEFLAGS,sESP,sSS };

struct {
        int     flag;
#define IPC_BUSY        1
#define IPC_WANT        2
#define IPC_DONE        4
        int     req;                    /* copy of ptrace request */
        int     *addr;                  /* copy of ptrace address */
        int     data;                   /* copy of ptrace data */
        int     error;                  /* errno from `procxmt' */
        int     regs[NIPCREG];          /* PT_[GS]ETREG */
        caddr_t buf;                    /* PT_BREAD/WRITE */
        int     buflen;                 /*      "       */
} ipc;

/*
 * Process debugging system call.
 */
ptrace(curp, uap, retval)
        struct proc *curp;
        register struct args {
                int     req;
                int     pid;
                int     *addr;
                int     data;
        } *uap;
        int *retval;
{
        struct proc *p;
        int s, error = 0;

        *retval = 0;
        if (uap->req == PT_TRACE_ME) {
                curp->p_flag |= STRC;
                /*p->p_tptr = p->p_pptr; * What shall we do here ? */
                return 0;
        }
        if ((p = pfind(uap->pid)) == NULL) {
                return ESRCH;
        }

#ifdef notyet
        if (uap->req != PT_ATTACH && (
                        (p->p_flag & STRC) == 0 ||
                        (p->p_tptr && curp != p->p_tptr) ||
                        (!p->p_tptr && curp != p->p_pptr)))

                return ESRCH;
#endif


#ifdef PT_ATTACH
        switch (uap->req) {
        case PT_ATTACH:
                if (curp->p_ucred->cr_uid != 0 && (
                        curp->p_ucred->cr_uid != p->p_ucred->cr_uid ||
                        curp->p_ucred->cr_uid != p->p_cred->p_svuid))
                        return EACCES;

                p->p_tptr = curp;
                p->p_flag |= STRC;
                psignal(p, SIGTRAP);
                return 0;

        case PT_DETACH:
                if ((unsigned)uap->data >= NSIG)
                        return EINVAL;
                p->p_flag &= ~(STRC|SSTRC|SFTRC);
                p->p_tptr = NULL;
                psignal(p->p_pptr, SIGCHLD);
                wakeup((caddr_t)p->p_pptr);
                s = splhigh();
                if (p->p_stat == SSTOP) {
                        p->p_xstat = uap->data;
                        setrun(p);
                } else if (uap->data) {
                        psignal(p, uap->data);
                }
                splx(s);
                return 0;

#ifdef PT_INHERIT
        case PT_INHERIT:
                if ((p->p_flag & STRC) == 0)
                        return ESRCH;
                p->p_flag |= SFTRC;
                return 0;
#endif

        default:
                break;
        }
#endif

        /* Other ptrace calls require target process to be in stopped state */
        if ((p->p_flag & STRC) == 0 || p->p_stat != SSTOP) {
                return ESRCH;
        }

        /* Acquire the ipc structure */
        while (ipc.flag & IPC_BUSY) {
                ipc.flag |= IPC_WANT;
                error = tsleep((caddr_t)&ipc, PWAIT|PCATCH, "ipc", 0);
                if (error)
                        goto out;
        }

        /* Got it, fill it */
        ipc.flag = IPC_BUSY;
        ipc.error = 0;
        ipc.req = uap->req;
        ipc.addr = uap->addr;
        ipc.data = uap->data;

#ifdef PT_GETREGS
        switch (uap->req) {
        case PT_SETREGS:
                error = copyin((char *)ipc.addr, (char *)ipc.regs, sizeof(ipc.regs));
                if (error)
                        goto out;
                break;

#ifdef notyet   /* requires change in number of args to ptrace syscall */
        case PT_BWRITE_I:
        case PT_BWRITE_D:
                ipc.buflen = uap->data;
                ipc.buf = kmem_alloc_wait(kernelmap, uap->data);
                error = copyin((char *)ipc.addr, (char *)ipc.buf, ipc.buflen);
                if (error) {
                        kmem_free_wakeup(kernelmap, ipc.buf, ipc.buflen);
                        goto out;
                }
#endif
        default:
                break;
        }
#endif

        setrun(p);
        while ((ipc.flag & IPC_DONE) == 0) {
                error = tsleep((caddr_t)&ipc, PWAIT|PCATCH, "ipc", 0);
                if (error)
                        goto out;
        }

        *retval = ipc.data;
        if (error = ipc.error)
                goto out;

#ifdef PT_GETREGS
        switch (uap->req) {
        case PT_GETREGS:
                error = copyout((char *)ipc.regs, (char *)ipc.addr, sizeof(ipc.regs));
                break;

        case PT_BREAD_I:
        case PT_BREAD_D:
                /* Not yet */
        default:
                break;
        }
#endif

out:
        /* Release ipc structure */
        ipc.flag &= ~IPC_BUSY;
        if (ipc.flag & IPC_WANT) {
                ipc.flag &= ~IPC_WANT;
                wakeup((caddr_t)&ipc);
        }
        return error;
}

procxmt(p)
        register struct proc *p;
{
        int i, *xreg, rv = 0;

        /* Are we still being traced? */
        if ((p->p_flag & STRC) == 0)
                return 1;

        p->p_addr->u_kproc.kp_proc = *p;
        fill_eproc(p, &p->p_addr->u_kproc.kp_eproc);

        switch (ipc.req) {
        case PT_READ_I:
        case PT_READ_D:
                ipc.error = copyin((char *)ipc.addr, (char *)&ipc.data, sizeof(ipc.data));
                break;

        case PT_READ_U:
                if ((u_int)ipc.addr > UPAGES * NBPG - sizeof(int)) {
                        ipc.error = EFAULT;
                        break;
                }
                ipc.data = *(int *)((u_int)p->p_addr + (u_int)ipc.addr);
                break;

        case PT_WRITE_I:
        case PT_WRITE_D:
                ipc.error = copyout((char *)&ipc.data, (char *)ipc.addr, sizeof(ipc.data));
                break;

        case PT_WRITE_U:
                if ((u_int)ipc.addr > UPAGES * NBPG - sizeof(int)) {
                        ipc.error = EFAULT;
                        break;
                }
                *(int *)((u_int)p->p_addr + (u_int)ipc.addr) = ipc.data;
                break;

        case PT_CONTINUE:
                if (ipc.addr != (int *)1) {
#ifdef i386
                        p->p_regs[(curpcb->pcb_flags&FM_TRAP)?tEIP:sEIP] = (int)ipc.addr;
#endif
                }
                p->p_flag &= ~SSTRC;    /* Only set by PT_SYSCALL */
                if ((unsigned)ipc.data >= NSIG) {
                        ipc.error = EINVAL;
                } else {
                        p->p_xstat = ipc.data;
                        rv = 1;
                }
                break;

        case PT_KILL:
                p->p_flag &= ~SSTRC;    /* Only set by PT_SYSCALL */
                rv = 2;
                break;

        case PT_STEP:
#ifdef i386
                if (ipc.addr != (int *)1) {
                        p->p_regs[(curpcb->pcb_flags&FM_TRAP)?tEIP:sEIP] = (int)ipc.addr;
                }
                p->p_regs[(curpcb->pcb_flags&FM_TRAP)?tEFLAGS:sEFLAGS] |= PSL_T;
#endif
                p->p_flag &= ~SSTRC;    /* Only set by PT_SYSCALL */
                p->p_xstat = 0;
                rv = 1;
                break;

#ifdef PT_SYSCALL
        case PT_SYSCALL:
                if (ipc.addr != (int *)1) {
#ifdef i386
                        p->p_regs[(curpcb->pcb_flags&FM_TRAP)?tEIP:sEIP] = (int)ipc.addr;
#endif
                }
                p->p_flag |= SSTRC;
                p->p_xstat = 0;
                rv = 1;
                break;
#endif
#ifdef PT_GETREGS
        case PT_GETREGS:
#ifdef i386
                xreg = (curpcb->pcb_flags&FM_TRAP)?ipcreg:sipcreg;
#endif

                for (i = 0; i < NIPCREG; i++)
                        ipc.regs[i] = p->p_regs[xreg[i]];
                break;

        case PT_SETREGS:
#ifdef i386
                xreg = (curpcb->pcb_flags&FM_TRAP)?ipcreg:sipcreg;
#endif

                for (i = 0; i < NIPCREG; i++)
                        p->p_regs[xreg[i]] = ipc.regs[i];
                break;
#endif

#ifdef PT_DUMP
        case PT_DUMP:
                /* Should be able to specify core file name */
                ipc.error = coredump(p);
                break;
#endif

        default:
                ipc.error = EINVAL;
        }
        ipc.flag |= IPC_DONE;
        wakeup((caddr_t)&ipc);

        if (rv == 2)
                exit(p, 0);     /*???*/

        return rv;
}

/*
 * Enable process profiling system call.
 */
/* ARGSUSED */
profil(p, uap, retval)
        struct proc *p;
        register struct args {
                short   *bufbase;       /* base of data buffer */
                unsigned bufsize;       /* size of data buffer */
                unsigned pcoffset;      /* pc offset (for subtraction) */
                unsigned pcscale;       /* scaling factor for offset pc */
        } *uap;
        int *retval;
{
        /* from looking at man pages, and include files, looks like
         * this just sets up the fields of p->p_stats->p_prof...
         * and those fields come straight from the args.
         * only thing *we* have to do is check the args for validity...
         *
         * cgd
         */

        /* check to make sure that the buffer is OK.  addupc (in locore)
         * checks for faults, but would one be generated, say, writing to
         * kernel space?  probably not -- it just uses "movl"...
         *
         * so we've gotta check to make sure that the info set up for
         * addupc is set right... it's gotta be writable by the user...
         */

        if (useracc(uap->bufbase,uap->bufsize*sizeof(short),B_WRITE) == 0)
                return EFAULT;

        p->p_stats->p_prof.pr_base = uap->bufbase;
        p->p_stats->p_prof.pr_size = uap->bufsize;
        p->p_stats->p_prof.pr_off = uap->pcoffset;
        p->p_stats->p_prof.pr_scale = uap->pcscale;

        return 0;
}