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Date: Mon, 28 Oct 2024 10:18:50 -0400
From: Steven Rostedt <rostedt@goodmis.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Masami
 Hiramatsu <mhiramat@kernel.org>, Mark Rutland <mark.rutland@arm.com>,
 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>, Andrew Morton
 <akpm@linux-foundation.org>, Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 5/5] ftrace: Use guard to take ftrace_lock in
 ftrace_graph_set_hash()
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On Mon, 28 Oct 2024 10:16:56 +0100
Peter Zijlstra <peterz@infradead.org> 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