Re: [RFC PATCH v2 02/20] tracing/filters: Enable filtering a cpumask field by another cpumask

Valentin Schneider
2023-07-31T11:21:01Z

On 29/07/23 15:09, Steven Rostedt wrote:
> On Wed, 26 Jul 2023 12:41:48 -0700
> Josh Poimboeuf <jpoimboe@kernel.org> wrote:
>
>> On Thu, Jul 20, 2023 at 05:30:38PM +0100, Valentin Schneider wrote:
>> > int filter_assign_type(const char *type)
>> > {
>> > - if (strstr(type, "__data_loc") && strstr(type, "char"))
>> > - return FILTER_DYN_STRING;
>> > + if (strstr(type, "__data_loc")) {
>> > + if (strstr(type, "char"))
>> > + return FILTER_DYN_STRING;
>> > + if (strstr(type, "cpumask_t"))
>> > + return FILTER_CPUMASK;
>> > + }
>>
>> The closing bracket has the wrong indentation.
>>
>> > + /* Copy the cpulist between { and } */
>> > + tmp = kmalloc((i - maskstart) + 1, GFP_KERNEL);
>> > + strscpy(tmp, str + maskstart, (i - maskstart) + 1);
>>
>> Need to check kmalloc() failure? And also free tmp?
>
> I came to state the same thing.
>
> Also, when you do an empty for loop:
>
> for (; str[i] && str[i] != '}'; i++);
>
> Always put the semicolon on the next line, otherwise it is really easy
> to think that the next line is part of the for loop. That is, instead
> of the above, do:
>
> for (; str[i] && str[i] != '}'; i++)
> ;
>

Interestingly I don't think I've ever encountered that variant, usually
having an empty line (which this lacks) and the indentation level is enough
to identify these - regardless, I'll change it.

>
> -- Steve
>
>
>>
>> > +
>> > + pred->mask = kzalloc(cpumask_size(), GFP_KERNEL);
>> > + if (!pred->mask)
>> > + goto err_mem;
>> > +
>> > + /* Now parse it */
>> > + if (cpulist_parse(tmp, pred->mask)) {
>> > + parse_error(pe, FILT_ERR_INVALID_CPULIST, pos + i);
>> > + goto err_free;
>> > + }
>> > +
>> > + /* Move along */
>> > + i++;
>> > + if (field->filter_type == FILTER_CPUMASK)
>> > + pred->fn_num = FILTER_PRED_FN_CPUMASK;
>> > +
>>