On Tue, Feb 25, 2025 at 11:04 AM Eduard Zingerman <eddyz87@xxxxxxxxx> wrote:
>
> On Tue, 2025-02-25 at 16:31 +0000, Mykyta Yatsenko wrote:
>
> New warning for trying to set non-enums from enumerators works fine.
> This still can be abused if numeric value outside of the supported
> range is specified, but that's fine, I think.
>
> Acked-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
>
> [...]
>
> > @@ -1292,6 +1320,268 @@ static int process_prog(const char *filename, struct bpf_object *obj, struct bpf
> > return 0;
> > };
> >
> > +static int append_var_preset(struct var_preset **presets, int *cnt, const char *expr)
> > +{
> > + void *tmp;
> > + struct var_preset *cur;
> > + char var[256], val[256];
> > + long long value;
> > + int r, n, val_len;
> > +
> > + tmp = realloc(*presets, (*cnt + 1) * sizeof(**presets));
> > + if (!tmp)
> > + return -ENOMEM;
> > + *presets = tmp;
> > + cur = &(*presets)[*cnt];
> > + cur->applied = false;
> > +
> > + if (sscanf(expr, "%s = %s\n", var, val) != 2) {
> > + fprintf(stderr, "Could not parse expression %s\n", expr);
> > + return -EINVAL;
> > + }
> > +
> > + val_len = strlen(val);
> > + errno = 0;
> > + r = sscanf(val, "%lli %n", &value, &n);
> > + if (r == 1 && n == val_len) {
> > + if (errno == ERANGE) {
> > + /* Try parsing as unsigned */
> > + errno = 0;
> > + r = sscanf(val, "%llu %n", &value, &n);
> > + /* Try hex if not all chars consumed */
> > + if (n != val_len) {
> > + errno = 0;
> > + r = sscanf(val, "%llx %n", &value, &n);
>
> The discrepancy between %lli accepting 0x but %llu not accepting 0x is
> annoying unfortunate. Does not look simpler then before, but let's
> merge this already.
yeah... with sscanf() we at least get whitespace trimming at end, so
don't need to check that. But I agree, doesn't look better.
>
> > + }
> > + }
> > + if (errno || r != 1 || n != val_len) {
> > + fprintf(stderr, "Could not parse value %s\n", val);
> > + return -EINVAL;
> > + }
> > + cur->ivalue = value;
> > + cur->type = INTEGRAL;
> > + } else {
> > + /* If not a number, consider it enum value */
> > + cur->svalue = strdup(val);
> > + if (!cur->svalue)
> > + return -ENOMEM;
> > +
> > + cur->type = ENUMERATOR;
> > + }
> > +
> > + cur->name = strdup(var);
> > + if (!cur->name)
> > + return -ENOMEM;
> > +
> > + (*cnt)++;
> > + return 0;
> > +}
>
> [...]
>
