Exemple #1
0
static int
kdb_ss(int argc, const char **argv)
{
	int ssb = 0;
	struct pt_regs *regs = get_irq_regs();

	ssb = (strcmp(argv[0], "ssb") == 0);
	if (argc != 0)
		return KDB_ARGCOUNT;

	if (!regs) {
		kdb_printf("%s: pt_regs not available\n", __FUNCTION__);
		return KDB_BADREG;
	}

	/*
	 * Set trace flag and go.
	 */
	KDB_STATE_SET(DOING_SS);
	if (ssb)
		KDB_STATE_SET(DOING_SSB);

	kdba_setsinglestep(regs);		/* Enable single step */

	if (ssb)
		return KDB_CMD_SSB;
	return KDB_CMD_SS;
}
kdb_dbtrap_t
kdba_bp_trap(struct pt_regs *regs, int error_unused)
{
	int i;
	kdb_dbtrap_t rv;
	kdb_bp_t *bp;

	if (KDB_NULL_REGS(regs))
		return KDB_DB_NOBPT;
	/*
	 * Determine which breakpoint was encountered.
	 */
	if (KDB_DEBUG(BP))
		kdb_printf("kdba_bp_trap: rip=0x%lx (not adjusted) "
			   "eflags=0x%lx ef=0x%p rsp=0x%lx\n",
			   regs->rip, regs->eflags, regs, regs->rsp);

	rv = KDB_DB_NOBPT;	/* Cause kdb() to return */

	for(i=0, bp=kdb_breakpoints; i<KDB_MAXBPT; i++, bp++) {
		if (bp->bp_free)
			continue;
		if (!bp->bp_global && bp->bp_cpu != smp_processor_id())
			continue;
		 if ((void *)bp->bp_addr == (void *)(regs->rip - bp->bp_adjust)) {
			/* Hit this breakpoint.  */
			regs->rip -= bp->bp_adjust;
			kdb_printf("Instruction(i) breakpoint #%d at 0x%lx (adjusted)\n",
				  i, regs->rip);
			kdb_id1(regs->rip);
			rv = KDB_DB_BPT;
			bp->bp_delay = 1;
			/* SSBPT is set when the kernel debugger must single
			 * step a task in order to re-establish an instruction
			 * breakpoint which uses the instruction replacement
			 * mechanism.  It is cleared by any action that removes
			 * the need to single-step the breakpoint.
			 */
			KDB_STATE_SET(SSBPT);
			break;
		}
	}

	return rv;
}
Exemple #3
0
int kdb_stub(struct kgdb_state *ks)
{
    int error = 0;
    kdb_bp_t *bp;
    unsigned long addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs);
    kdb_reason_t reason = KDB_REASON_OOPS;
    kdb_dbtrap_t db_result = KDB_DB_NOBPT;
    int i;

    if (KDB_STATE(REENTRY)) {
        reason = KDB_REASON_SWITCH;
        KDB_STATE_CLEAR(REENTRY);
        addr = instruction_pointer(ks->linux_regs);
    }
    ks->pass_exception = 0;
    if (atomic_read(&kgdb_setting_breakpoint))
        reason = KDB_REASON_KEYBOARD;

    for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) {
        if ((bp->bp_enabled) && (bp->bp_addr == addr)) {
            reason = KDB_REASON_BREAK;
            db_result = KDB_DB_BPT;
            if (addr != instruction_pointer(ks->linux_regs))
                kgdb_arch_set_pc(ks->linux_regs, addr);
            break;
        }
    }
    if (reason == KDB_REASON_BREAK || reason == KDB_REASON_SWITCH) {
        for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) {
            if (bp->bp_free)
                continue;
            if (bp->bp_addr == addr) {
                bp->bp_delay = 1;
                bp->bp_delayed = 1;
                /*
                 * SSBPT is set when the kernel debugger must single step a
                 * task in order to re-establish an instruction breakpoint
                 * which uses the instruction replacement mechanism.  It is
                 * cleared by any action that removes the need to single-step
                 * the breakpoint.
                 */
                reason = KDB_REASON_BREAK;
                db_result = KDB_DB_BPT;
                KDB_STATE_SET(SSBPT);
                break;
            }
        }
    }

    if (reason != KDB_REASON_BREAK && ks->ex_vector == 0 &&
            ks->signo == SIGTRAP) {
        reason = KDB_REASON_SSTEP;
        db_result = KDB_DB_BPT;
    }
    /* Set initial kdb state variables */
    KDB_STATE_CLEAR(KGDB_TRANS);
    kdb_initial_cpu = ks->cpu;
    kdb_current_task = kgdb_info[ks->cpu].task;
    kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo;
    /* Remove any breakpoints as needed by kdb and clear single step */
    kdb_bp_remove();
    KDB_STATE_CLEAR(DOING_SS);
    KDB_STATE_CLEAR(DOING_SSB);
    KDB_STATE_SET(PAGER);
    /* zero out any offline cpu data */
    for_each_present_cpu(i) {
        if (!cpu_online(i)) {
            kgdb_info[i].debuggerinfo = NULL;
            kgdb_info[i].task = NULL;
        }
    }
    if (ks->err_code == DIE_OOPS || reason == KDB_REASON_OOPS) {
        ks->pass_exception = 1;
        KDB_FLAG_SET(CATASTROPHIC);
    }
    kdb_initial_cpu = ks->cpu;
    if (KDB_STATE(SSBPT) && reason == KDB_REASON_SSTEP) {
        KDB_STATE_CLEAR(SSBPT);
        KDB_STATE_CLEAR(DOING_SS);
    } else {
        /* Start kdb main loop */
        error = kdb_main_loop(KDB_REASON_ENTER, reason,
                              ks->err_code, db_result, ks->linux_regs);
    }
    /*
     * Upon exit from the kdb main loop setup break points and restart
     * the system based on the requested continue state
     */
    kdb_initial_cpu = -1;
    kdb_current_task = NULL;
    kdb_current_regs = NULL;
    KDB_STATE_CLEAR(PAGER);
    kdbnearsym_cleanup();
    if (error == KDB_CMD_KGDB) {
        if (KDB_STATE(DOING_KGDB) || KDB_STATE(DOING_KGDB2)) {
            /*
             * This inteface glue which allows kdb to transition in into
             * the gdb stub.  In order to do this the '?' or '' gdb serial
             * packet response is processed here.  And then control is
             * passed to the gdbstub.
             */
            if (KDB_STATE(DOING_KGDB))
                gdbstub_state(ks, "?");
            else
                gdbstub_state(ks, "");
            KDB_STATE_CLEAR(DOING_KGDB);
            KDB_STATE_CLEAR(DOING_KGDB2);
        }
        return DBG_PASS_EVENT;
    }
    kdb_bp_install(ks->linux_regs);
    dbg_activate_sw_breakpoints();
    /* Set the exit state to a single step or a continue */
    if (KDB_STATE(DOING_SS))
        gdbstub_state(ks, "s");
    else
        gdbstub_state(ks, "c");

    KDB_FLAG_CLEAR(CATASTROPHIC);

    /* Invoke arch specific exception handling prior to system resume */
    kgdb_info[ks->cpu].ret_state = gdbstub_state(ks, "e");
    if (ks->pass_exception)
        kgdb_info[ks->cpu].ret_state = 1;
    if (error == KDB_CMD_CPU) {
        KDB_STATE_SET(REENTRY);
        /*
         * Force clear the single step bit because kdb emulates this
         * differently vs the gdbstub
         */
        kgdb_single_step = 0;
        dbg_deactivate_sw_breakpoints();
        return DBG_SWITCH_CPU_EVENT;
    }
    return kgdb_info[ks->cpu].ret_state;
}
Exemple #4
0
static void kdb_setsinglestep(struct pt_regs *regs)
{
	KDB_STATE_SET(DOING_SS);
}