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Date: Fri, 4 Apr 2025 10:04:00 -0400
From: Steven Rostedt <rostedt@goodmis.org>
To: LKML <linux-kernel@vger.kernel.org>, Linux Trace Kernel
 <linux-trace-kernel@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>, Mathieu Desnoyers
 <mathieu.desnoyers@efficios.com>, Tom Zanussi <zanussi@kernel.org>
Subject: Re: [PATCH] tracing: Move histogram trigger variables from stack to
 per CPU structure
Message-ID: <20250404100400.22195057@gandalf.local.home>
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On Fri, 4 Apr 2025 09:58:41 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> Hmm, this is incorrect. hist_pads can be NULL or allocated, so the check
> should be:
> 
> 	if (!hist_pads)
> 		goto fail;
> 	hist_pad = per_cpu_ptr(hist_pads, smp_processor_id());
> 
> Will send v2.

In fact, if hist_pads fails to allocate, the triggers should not be enabled
(it would fail to enable). So I'll just add to the start of the function:

	if (WARN_ON_ONCE(!hist_pads))
		return NULL;

-- Steve