Language/OS - Multiplatform Resource Library/LANGUAGE OS.iso/pcr/pcr4_4.lha/DIST/debugnub/CirioNubStoreBytesToText.c

C/C++ Source or Header | 1991-06-17 | 5KB | 181 lines

/* begincopyright
  Copyright (c) 1991 Xerox Corporation. All rights reserved.
  Use and copying of this software and preparation of derivative works based
  upon this software are permitted. Any distribution of this software or
  derivative works must comply with all applicable United States export
  control laws. This software is made available AS IS, and Xerox Corporation
  makes no warranty about the software, its performance or its conformity to
  any specification. Any person obtaining a copy of this software is requested
  to send their name and post office or electronic mail address to:
    PCR Coordinator
    Xerox PARC
    3333 Coyote Hill Rd.
    Palo Alto, CA 94304
  endcopyright */

/*
 * CirioNubStoreBytesToText.c
 *
 * Demers, June 6, 1991 2:49:24 pm PDT
 */

/*
    NOTE: This doesn't need to use ptrace -- it could instead
    issue vp orders to get each vp to write-enable that part
    of the text segment it needs to write in.  The semantics
    would still be copy-on-write, the code would be somewhat
    more complex.  The result would work on SVR4, but not in AIX.
    So much for standards.
*/

#include "xr/Errno.h"
#include "xr/ThreadsBackdoor.h"
#include "xr/CirioNubProtocol.h"
#include "xr/CirioNubMarshall.h"
#include "xr/CirioNubProcs.h"
#include "xr/CirioNubEnvironment.h"

#include "xr/ThreadsMsg.h"

#include <signal.h>
#include <sys/ptrace.h>
#include <sys/wait.h>

#define    DEBUG_STORE 1
#define    DEBUG_FETCH 1
#undef    DEBUG_FETCH

extern int etext;

#define TEXTSTART    ((char *)(8*1024))
#define TEXTLIM        ((char *)(&etext))

bool
CirioNubIsTextAddress(addr)
    char *addr;
{
    if( addr < TEXTSTART ) return FALSE;
    if( addr >= TEXTLIM) return FALSE;
    return TRUE;
}



CirioNubRetCode
CirioNubStoreBytesToVPTextSegments(bytes, addr, nBytes)
    char *bytes;
    char *addr;
    int nBytes;
{
    int ans, status, i;
    int pid = 0;

    if( !CirioNubIsTextAddress(addr) ) {
        return CirioNubPutInt32(-1);
    }

    for( i = 0; i < XR_sysArea->sa_numVP; i++ ) {
        pid = XR_sysArea->sa_vpe[i].vpe_pid;
        ans = ptrace(PTRACE_ATTACH, pid, 0, 0, 0);
        if( ans == (-1) ) {
#           ifdef DEBUG_STORE
                XR_ConsoleMsg("Can't attach pid %d err %d\n", pid, errno);
#           endif
            pid = 0;  goto Bad;
        }
        for(;;) {
            ans = waitpid(pid, &status, WUNTRACED);
            if( ans != (-1) ) break;
            if( errno == ECHILD ) {
#               ifdef DEBUG_STORE
                    XR_ConsoleMsg("Can't wait pid %d err %d\n", pid, errno);
#               endif
                goto Bad;
            }
        }
        ans = ptrace(PTRACE_WRITETEXT, pid, addr, nBytes, bytes);
        if( ans == (-1) ) {
#           ifdef DEBUG_STORE
                XR_ConsoleMsg("Can't write pid %d err %d\n", pid, errno);
#           endif
            goto Bad;
        }
        ans = ptrace(PTRACE_DETACH, pid, ((int *)(1)), SIGUSR1, 0);
        if( ans == (-1) ) {
#           ifdef DEBUG_STORE
                XR_ConsoleMsg("Can't detach pid %d err %d\n", pid, errno);
#           endif
            pid = 0; goto Bad;
        }
    }
    return CirioNubPutInt32(0);

  Bad:
    if( pid != 0 ) {
        (void)ptrace(PTRACE_DETACH, pid, ((int *)(1)), SIGUSR1, 0);
    }
    return CirioNubPutInt32(-1);
}



int
CirioNubFetchBytesFromVPTextSegment(bytes, addr, nBytes, vpi)
    char *bytes;
    char *addr;
    int nBytes;
    int vpi;
{
    int ans, status;
    int pid;

    if( !CirioNubIsTextAddress(addr) ) {
        return (-1);
    }

    {
        pid = XR_sysArea->sa_vpe[vpi].vpe_pid;
        ans = ptrace(PTRACE_ATTACH, pid, 0, 0, 0);
        if( ans == (-1) ) {
#           ifdef DEBUG_FETCH
                XR_ConsoleMsg("Can't attach pid %d err %d\n", pid, errno);
#           endif
            pid = 0; goto Bad;
        }
        for(;;) {
            ans = waitpid(pid, &status, WUNTRACED);
            if( ans != (-1) ) break;
            if( errno == ECHILD ) {
#               ifdef DEBUG_FETCH
                    XR_ConsoleMsg("Can't wait pid %d err %d\n", pid, errno);
#               endif
                goto Bad;
            }
        }
        ans = ptrace(PTRACE_READTEXT, pid, addr, nBytes, bytes);
        if( ans == (-1) ) {
#           ifdef DEBUG_FETCH
                XR_ConsoleMsg("Can't read pid %d err %d\n", pid, errno);
#           endif
            goto Bad;
        }
        ans = ptrace(PTRACE_DETACH, pid, ((int *)(1)), SIGUSR1, 0);
        if( ans == (-1) ) {
#           ifdef DEBUG_FETCH
                XR_ConsoleMsg("Can't detach pid %d err %d\n", pid, errno);
#           endif
            pid = 0;  goto Bad;
        }
    }
    return 0;

  Bad:
    if( pid != 0 ) {
        (void) ptrace(PTRACE_DETACH, pid, ((int *)(1)), SIGUSR1, 0);
    }
    return (-1);
}