Re: [PATCH v2 2/5] ftrace: Do not add duplicate entries in subops manager ops

[Google]

On Wed, 19 Feb 2025 17:04:38 -0500
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> From: Steven Rostedt <rostedt@xxxxxxxxxxx>
> 
> Check if a function is already in the manager ops of a subops. A manager
> ops contains multiple subops, and if two or more subops are tracing the
> same function, the manager ops only needs a single entry in its hash.
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 4f554e955614f ("ftrace: Add ftrace_set_filter_ips function")
> Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>

Looks good to me.

Reviewed-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>

Thank you,

> ---
>  kernel/trace/ftrace.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 03b35a05808c..189eb0a12f4b 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -5717,6 +5717,9 @@ __ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
>  			return -ENOENT;
>  		free_hash_entry(hash, entry);
>  		return 0;
> +	} else if (__ftrace_lookup_ip(hash, ip) != NULL) {
> +		/* Already exists */
> +		return 0;
>  	}
>  
>  	entry = add_hash_entry(hash, ip);
> -- 
> 2.47.2
> 
> 


-- 
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>