Re: [PATCH RFC bpf-next 2/6] bpf: compute loops hierarchy

[Eduard Zingerman <eddyz87@gmail.com>]

On Tue, 2026-05-26 at 10:05 +0000, bot+bpf-ci@kernel.org wrote:

[...]

> > +int bpf_compute_loops(struct bpf_verifier_env *env)
> > +{
> > +	struct bpf_insn_aux_data *aux = env->insn_aux_data;
> > +	int i, err = 0, len = env->prog->len;
> > +	struct loops_dfs dfs = {};
> > +
> > +	dfs.dfs_pos = kvcalloc(len, sizeof(int), GFP_KERNEL_ACCOUNT);
> > +	dfs.state = kvcalloc(len, sizeof(struct dfs_state), GFP_KERNEL_ACCOUNT);
> > +	dfs.stack = kvcalloc(len, sizeof(int), GFP_KERNEL_ACCOUNT);
> > +	if (!dfs.dfs_pos || !dfs.state || !dfs.stack) {
> > +		err = -ENOMEM;
> > +		goto out;
> > +	}
> > +	for (i = 0; i < len; i++)
> > +		aux[i].loop_header = -1;
> > +	for (i = 0; i < env->subprog_cnt; i++) {
> > +		err = compute_loops_in_subprog(env, &dfs, i);
> > +		if (err)
> > +			goto out;
> > +	}
> > +
> > +out:
> > +	kfree(dfs.dfs_pos);
> > +	kfree(dfs.stack);
> > +	kfree(dfs.state);
> > +	return err;
> > +}
> 
> Should this use kvfree() instead of kfree()? The three buffers are
> allocated with kvcalloc(), which can return either kmalloc or vmalloc
> memory depending on size. With env->prog->len up to 1,000,000
> instructions, these allocations can easily exceed kmalloc's maximum
> size and fall back to vmalloc.

It should use kvfree(), yes.