Re: [Qemu-devel] [PATCH v7 2/2] gdbstub: Fix vCont behaviour

[Paolo Bonzini]

On 27/01/2017 19:11, Claudio Imbrenda wrote:
> +    /* mark valid CPUs with 1 */
> +    CPU_FOREACH(cpu) {
> +        newstates[cpu_index(cpu) - 1] = 1;
> +    }

Sorry I didn't notice this before: CPU indices are zero-based in QEMU,
so you are probably overwriting newstates[-1].  I can adjust it myself,
but can you please double check?

Paolo

> +
> +    /*
> +     * res keeps track of what error we are returning, with -1 meaning
> +     * that the command is unknown or unsupported, and thus returning
> +     * an empty packet, while -22 returns an E22 packet due to
> +     * invalid or incorrect parameters passed.
> +     */
> +    res = 0;
> +    while (*p) {
> +        if (*p++ != ';') {
> +            res = -ENOTSUP;
> +            goto out;
> +        }
> +
> +        cur_action = *p++;
> +        if (cur_action == 'C' || cur_action == 'S') {
> +            cur_action = tolower(cur_action);
> +            res = qemu_strtoul(p + 1, &p, 16, &tmp);
> +            if (res) {
> +                goto out;
> +            }
> +            signal = gdb_signal_to_target(tmp);
> +        } else if (cur_action != 'c' && cur_action != 's') {
> +            /* unknown/invalid/unsupported command */
> +            res = -ENOTSUP;
> +            goto out;
> +        }
> +        /* thread specification. special values: (none), -1 = all; 0 = any */
> +        if ((p[0] == ':' && p[1] == '-' && p[2] == '1') || (p[0] != ':')) {
> +            if (*p == ':') {
> +                p += 3;
> +            }
> +            for (idx = 0; idx < max_cpus; idx++) {
> +                if (newstates[idx] == 1) {
> +                    newstates[idx] = cur_action;
> +                }
> +            }
> +        } else if (*p == ':') {
> +            p++;
> +            res = qemu_strtoul(p, &p, 16, &tmp);
> +            if (res) {
> +                goto out;
> +            }
> +            idx = tmp;
> +            /* 0 means any thread, so we pick the first valid CPU */
> +            if (!idx) {
> +                idx = cpu_index(first_cpu);
> +            }
> +
> +            /* invalid CPU specified */
> +            if (!idx || idx > max_cpus || !newstates[idx - 1]) {
> +                res = -EINVAL;
> +                goto out;
> +            }
> +            /* only use if no previous match occourred */
> +            if (newstates[idx - 1] == 1) {
> +                newstates[idx - 1] = cur_action;
> +            }
> +        }