strace_ppc.c

完整的Bell实验室的嵌入式文件系统TFS

/* strace.c:
 *
 *  General notice:
 *  This code is part of a boot-monitor package developed as a generic base
 *  platform for embedded system designs.  As such, it is likely to be
 *  distributed to various projects beyond the control of the original
 *  author.  Please notify the author of any enhancements made or bugs found
 *  so that all may benefit from the changes.  In addition, notification back
 *  to the author will allow the new user to pick up changes that may have
 *  been made by other users after this version of the code was distributed.
 *
 *  Note1: the majority of this code was edited with 4-space tabs.
 *  Note2: as more and more contributions are accepted, the term "author"
 *         is becoming a mis-representation of credit.
 *
 *  Original author:    Ed Sutter
 *  Email:              [e-mail]
 *  Phone:              908-582-2351
 *
 *  Note that this stack trace can be used to trace REAL exceptions or
 *  user-induced exceptions.  If one is user-induced, then the user is
 *  typically just replacing an instruction at the point at which the break
 *  is to occur with a SC (syscall) instruction.  The point at which this
 *  insertion is made must be after the function sets up its stack frame
 *  otherwise it is likely that the trace will be bogus.
 *
 *  BTW... the SC instruction is 0x44000002.
 */
#include "config.h"
#if INCLUDE_STRACE
#include "tfs.h"
#include "tfsprivate.h"
#include "ctype.h"
#include "genlib.h"
#include "stddefs.h"

char *StraceHelp[] = {
    "Stack trace",
    "-[a:d:F:P:rs:v]",
    " -a #   fp adjustment",
    " -d #   max depth count (def=20)",
    " -F #   specify frame-pointer (don't use content of R1)",
    " -P #   specify PC (don't use content of SRR#)",
    " -r     dump regs",
    " -s #   srr reg num (def=0)",
    " -v     verbose",
    0,
};

int
Strace(argc,argv)
int argc;
char    *argv[];
{
    char    *symfile, fname[64];
    TFILE   *tfp;
    ulong   *framepointer, pc, fp, offset;
    int     tfd, opt, srrnum, maxdepth, pass, verbose, fadjust;

    tfd = fp = 0;
    srrnum = -1;
    maxdepth = 20;
    verbose = 0;
    fadjust = 0;
    pc = ExceptionAddr;
    while ((opt=getopt(argc,argv,"a:d:F:P:rs:v")) != -1) {
        switch(opt) {
        case 'a':
            fadjust = atoi(optarg);
            break;
        case 'd':
            maxdepth = atoi(optarg);
            break;
        case 'F':
            fp = strtoul(optarg,0,0);
            break;
        case 'P':
            pc = strtoul(optarg,0,0);
            break;
        case 'r':
            showregs();
            break;
        case 's':
            srrnum = atoi(optarg);
            break;
        case 'v':
            verbose = 1;
            break;
        default:
            return(0);
        }
    }
    
    if (!fp)
        getreg("R1", (ulong *)&framepointer);
    else
        framepointer = (ulong *)fp;

    if (srrnum != -1) {
        if (srrnum == 0)
            getreg("SRR0", &pc);
        else if (srrnum == 2)
            getreg("SRR2", &pc);
        else  {
            printf("Invalid -s value\n");
            return(0);
        }
    }

    /* Start by detecting the presence of a symbol table file... */
    symfile = getenv("SYMFILE");
    if (!symfile)
        symfile = SYMFILE;

    tfp = tfsstat(symfile);
    if (tfp)  {
        tfd = tfsopen(symfile,TFS_RDONLY,0);
        if (tfd < 0)
            tfp = (TFILE *)0;
    }

    /* Show current position: */
    printf("   0x%08lx",pc);
    if (tfp) {
        AddrToSym(tfd,pc,fname,&offset);
        printf(": %s()",fname);
        if (offset)
            printf(" + 0x%lx",offset);
    }
    putchar('\n');

    /* Now step through the stack frame... */
    pass = 0;
    while(maxdepth) {
        /* If we are at the first instruction of a function (offset=0),
         * and this is the first pass in this loop; then we assume that
         * this function's frame has not been accounted for yet...
         */
        if ((pass == 0) && (offset == 0)) {
        }
        else {
            framepointer = (ulong *)*(framepointer + fadjust);
        }

        pc = *(framepointer + fadjust + 1);

        if (verbose) {
            printf("fp=0x%lx,*fp=0x%lx,pc=%lx\n", (ulong)framepointer,
                (ulong)*framepointer,pc);
        }

        if (((ulong)framepointer & 3) || (!framepointer) ||
            (!*framepointer) || (!pc)) {
            break;
        }

        printf("   0x%08lx",pc);
        if (tfp) {
            int match;

            match = AddrToSym(tfd,pc,fname,&offset);
            printf(": %s()",fname);
            if (offset)
                printf(" + 0x%lx",offset);
            if (!match) {
                putchar('\n');
                break;
            }
        }
        putchar('\n');
        maxdepth--;
        pass++;
    }

    if (!maxdepth)
        printf("Max depth termination\n");
    
    if (tfp) {
        tfsclose(tfd,0);
    }
    return(0);
}
#endif