On Fri, 2 Jul 2021 14:10:46 +0300
"Yordan Karadzhov (VMware)" <y.karadz@xxxxxxxxx> wrote:
> > +static int build_list(const char *name, void *data)
> > +{
> > + struct instance_list *list = data;
> > + char **instances;
> > + int ret = -1;
> > +
> > + if (!match(name, list->re))
> > + return 0;
> > +
> > + instances = realloc(list->list, list->size + 2);
> > + if (!instances)
> > + goto out;
> > +
> > + list->list = instances;
> Hi Steven,
>
> I am not sure what was your original intention here, but this doesn't
> seem to work properly. Maybe we need something like this:
>
> int size = sizeof(*instances) * (list->size + 2);
> instances = realloc(list->list, size);
Bah, that's what I get for trying to "multitask" while coding :-p
That was suppose to be:
instances = realloc(list->list, sizeof(*instances) * (list->size + 2);
as you stated, but I'll keep it one line.
> if (!instances)
> goto out;
>
> instances[list->size + 1] = NULL;
>
>
>
>
> > + list->list[list->size] = strdup(name);
> > + if (!list->list[list->size])
> > + goto out;
> > +
> > + list->size++;
> > + ret = 0;
> > +
> > + out:
> > + list->failed = ret;
> > + return ret;
> > +}
> > +
> > +/**
> > + * tracefs_instances - return a list of instance names
> > + * @regex: A regex of instances to filter on (NULL to match all)
> > + *
> > + * Returns a list of names of existing instances, that must be
> > + * freed with tracefs_list_free(). Note, if there are no matches
> > + * then an empty list will be returned (not NULL).
> > + * NULL on error.
> > + */
> > +char **tracefs_instances(const char *regex)
> > +{
> > + struct instance_list list = { .re = NULL, .list = NULL };
> > + regex_t re;
> > + int ret;
> > +
> > + if (regex) {
> > + ret = regcomp(&re, regex, REG_ICASE|REG_NOSUB);
> > + if (ret < 0)
> > + return NULL;
> > + list.re = &re;
> > + }
> > +
> > + ret = tracefs_instances_walk(build_list, &list);
> > + if (ret < 0 || list.failed) {
> > + tracefs_list_free(list.list);
> > + list.list = NULL;
> > + } else {
> > + if (!list.list) {
> > + /* No matches should produce an empty list */
> > + list.list = malloc(sizeof(*list.list));
> > + if (list.list)
> > + list.list[0] = NULL;
> > + }
>
> Or you can just do:
> return calloc(1, sizeof(*list.list));
Which I do in tracefs_get_probes(), must have missed this one.
Will update, thanks for the review.
-- Steve
>
> Thanks!
> Yordan
>
> > + }
> > + return list.list;
> > +}
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