/* stacktrace.c - stacktrace */
#include 

#define STKDETAIL

/*------------------------------------------------------------------------
 * stacktrace - print a stack backtrace for a process
 *------------------------------------------------------------------------
 */
syscall stacktrace(int pid)
{
        struct procent  *proc = &proctab[pid];
        unsigned long   *sp, *fp;

        if (pid != 0 && isbadpid(pid))
                return SYSERR;
        if (pid == currpid) {
                asm("movl %%esp, %0\n" :"=r"(sp));
                asm("movl %%ebp, %0\n" :"=r"(fp));
        } else {
                sp = (unsigned long *)proc->prstkptr;
                fp = sp + 2;            /* Where ctxsw leaves it */
        }
        kprintf("sp %X fp %X proc->prstkbase %X\n", sp, fp, proc->prstkbase);
#ifdef STKDETAIL
        while (sp < (unsigned long *)proc->prstkbase) {
                for (; sp < fp; sp++)
                        kprintf("DATA (%08X) %08X (%d)\n", sp, *sp, *sp);
                if (*sp == STACKMAGIC)
                        break;
                kprintf("\nFP   (%08X) %08X (%d)\n", sp, *sp, *sp);
                fp = (unsigned long *) *sp++;
                if (fp <= sp) {
                        kprintf("bad stack, fp (%08X) <= sp (%08X)\n", fp, sp);
                        return SYSERR;
                }
                kprintf("RET  0x%X\n", *sp);
                sp++;
        }
        kprintf("STACKMAGIC (should be %X): %X\n", STACKMAGIC, *sp);
        if (sp != (unsigned long *)proc->prstkbase) {
                kprintf("unexpected short stack\n");
                return SYSERR;
        }
#endif
        return OK;
}