Re: [PATCH 5/5] ftrace: Use guard to take ftrace_lock in ftrace_graph_set_hash()

[Steven Rostedt]

On Mon, 28 Oct 2024 10:16:56 +0100
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> > @@ -6846,13 +6844,8 @@ ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
> >  			}
> >  		}
> >  	} while_for_each_ftrace_rec();
> > -out:
> > -	mutex_unlock(&ftrace_lock);
> >  
> > -	if (fail)
> > -		return -EINVAL;
> > -
> > -	return 0;
> > +	return fail ? -EINVAL : 0;
> >  }  
> 
> Isn't the fail case more a case of -ESRCH / -ENOENT rather than -EINVAL?

Could be. Although this is mostly for internal use. I should check to
see if this gets back to user space. And yeah, it probably should be
changed.

> 
> Anyway, that's orthogonal, the patch preserves existing semantics and
> looks okay (as do the others fwiw).

Thanks for the review!

-- Steve