Re: [PATCH v19 10/15] trace-cmd: Add guest information in host's trace.dat file

[Steven Rostedt <rostedt@goodmis.org>]

On Fri, 31 Jan 2020 14:11:06 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:

> +static int trace_guest_load(struct tracecmd_input *handle, char *buf, int size)
> +{
> +	struct guest_trace_info *guest = NULL;
> +	int cpu;
> +	int i;
> +
> +	guest = calloc(1, sizeof(struct guest_trace_info));
> +	if (!guest)
> +		goto error;
> +
> +	/*
> +	 * Guest name, null terminated string
> +	 * long long (8 bytes) trace-id
> +	 * int (4 bytes) number of guest CPUs
> +	 * array of size number of guest CPUs:
> +	 *	int (4 bytes) Guest CPU id
> +	 *	int (4 bytes) Host PID, running the guest CPU
> +	 */
> +
> +	guest->name = strndup(buf, size);
> +	if (!guest->name)
> +		goto error;
> +	buf += strlen(guest->name) + 1;
> +	size -= strlen(guest->name) + 1;
> +
> +	if (size < sizeof(long long))
> +		goto error;
> +	guest->trace_id = tep_read_number(handle->pevent, buf, sizeof(long long));
> +	buf += sizeof(long long);

Don't we need:

	size -= sizeof(long long);

> +
> +	if (size < sizeof(int))
> +		goto error;
> +	guest->vcpu_count = tep_read_number(handle->pevent, buf, sizeof(int));
> +	buf += sizeof(int);

	size -= sizeof(int);

> +
> +	guest->cpu_pid = calloc(guest->vcpu_count, sizeof(int));
> +	if (!guest->cpu_pid)
> +		goto error;
> +
> +	for (i = 0; i < guest->vcpu_count; i++) {
> +		if (size < 2 * sizeof(int))
> +			goto error;
> +		cpu = tep_read_number(handle->pevent, buf, sizeof(int));
> +		buf += sizeof(int);
> +		if (cpu >= guest->vcpu_count)
> +			goto error;
> +		guest->cpu_pid[cpu] = tep_read_number(handle->pevent,
> +						      buf, sizeof(int));
> +		buf += sizeof(int);

		size -= 2 * sizeof(int);

-- Steve

> +	}
> +
> +	guest->next = handle->guest;
> +	handle->guest = guest;
> +	return 0;
> +
> +error:
> +	if (guest) {
> +		free(guest->cpu_pid);
> +		free(guest->name);
> +		free(guest);
> +	}
> +	return -1;
> +}
> +