Re: [PATCH 2/2] tracing: fprobe: Fix to remove recorded module addresses from filter

[menglong.dong@linux.dev]

On 2025/9/24 08:26 Masami Hiramatsu (Google) <mhiramat@kernel.org> write:
> From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> 
> Even if there is a memory allocation failure in fprobe_addr_list_add(),
> there is a partial list of module addresses. So remove the recorded
> addresses from filter if exists.
> This also removes the redundant ret local variable.

I think this is what you do in the previous patch?

The rest looks good to me.

Reviewed-by: Menglong Dong <menglong8.dong@gmail.com>

(I think I should use Reviewed-by here, rather than Acked-by,
right?)

Thanks!
Menglong Dong

> 
> Fixes: a3dc2983ca7b ("tracing: fprobe: Cleanup fprobe hash when module unloading")
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> ---
>  kernel/trace/fprobe.c |    7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
> index 12ec194fdfed..95e43814b85b 100644
> --- a/kernel/trace/fprobe.c
> +++ b/kernel/trace/fprobe.c
> @@ -434,8 +434,9 @@ static int fprobe_addr_list_add(struct fprobe_addr_list *alist, unsigned long ad
>  {
>  	unsigned long *addrs;
>  
> -	if (alist->index >= alist->size)
> -		return -ENOMEM;
> +	/* Previously we failed to expand the list. */
> +	if (alist->index == alist->size)
> +		return -ENOSPC;
>  
>  	alist->addrs[alist->index++] = addr;
>  	if (alist->index < alist->size)
> @@ -497,7 +498,7 @@ static int fprobe_module_callback(struct notifier_block *nb,
>  	} while (node == ERR_PTR(-EAGAIN));
>  	rhashtable_walk_exit(&iter);
>  
> -	if (alist.index < alist.size && alist.index > 0)
> +	if (alist.index > 0)
>  		ftrace_set_filter_ips(&fprobe_graph_ops.ops,
>  				      alist.addrs, alist.index, 1, 0);
>  	mutex_unlock(&fprobe_mutex);
> 
> 
>