Re: [PATCH perf/core 1/4] uprobes: simplify session consumer tracking

[Jiri Olsa]

On Thu, Dec 05, 2024 at 04:24:14PM -0800, Andrii Nakryiko wrote:

SNIP

>  static struct return_instance *alloc_return_instance(void)
>  {
>  	struct return_instance *ri;
>  
> -	ri = kzalloc(ri_size(DEF_CNT), GFP_KERNEL);
> +	ri = kzalloc(sizeof(*ri), GFP_KERNEL);
>  	if (!ri)
>  		return ZERO_SIZE_PTR;
>  
> -	ri->consumers_cnt = DEF_CNT;
>  	return ri;
>  }
>  
>  static struct return_instance *dup_return_instance(struct return_instance *old)
>  {
> -	size_t size = ri_size(old->consumers_cnt);
> +	struct return_instance *ri;
> +
> +	ri = kmemdup(old, sizeof(*ri), GFP_KERNEL);

missing ri == NULL check

jirka

> +
> +	if (unlikely(old->cons_cnt > 1)) {
> +		ri->extra_consumers = kmemdup(old->extra_consumers,
> +					      sizeof(ri->extra_consumers[0]) * (old->cons_cnt - 1),
> +					      GFP_KERNEL);
> +		if (!ri->extra_consumers) {
> +			kfree(ri);
> +			return NULL;
> +		}
> +	}
>  
> -	return kmemdup(old, size, GFP_KERNEL);
> +	return ri;
>  }
>  
>  static int dup_utask(struct task_struct *t, struct uprobe_task *o_utask)
> @@ -2369,25 +2372,28 @@ static struct uprobe *find_active_uprobe_rcu(unsigned long bp_vaddr, int *is_swb
>  	return uprobe;
>  }
>  
> -static struct return_instance*

SNIP