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From: "Liam R. Howlett" <Liam.Howlett@oracle.com>
To: Martin Kaiser <martin@kaiser.cx>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	maple-tree@lists.infradead.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] maple_tree: fix tracepoint string pointers
Date: Fri, 31 Oct 2025 09:08:28 -0400	[thread overview]
Message-ID: <kfzgcg2ir4v3evxnlfui7jrip3zozsmpxj6mdisshw5won6qvs@n63xfjfnlxkn> (raw)
In-Reply-To: <aQSOAkBbFkBfYxPs@akranes.kaiser.cx>

* Martin Kaiser <martin@kaiser.cx> [251031 06:23]:
> Thus wrote Andrew Morton (akpm@linux-foundation.org):
> 
> > > -	trace_ma_op(__func__, mas);
> > > +	trace_ma_op(TP_FCT, mas);
> 
> 
> > What could cause the storage for __func__ to disappear as you suggest?
> 
> I see your point. For __func__, the compiler generates a local symbol in
> .rodata that should always be accessible by its address.
> 
> One case that doesn't work without my patch would be trace-cmd record to save
> the binary ringbuffer and trace-cmd report to parse it in userspace. The
> address of __func__ can't be dereferenced from userspace but tracepoint_string
> will add an entry to /sys/kernel/tracing/printk_formats
> 


Thanks.

Is there some way to detect such things at compile?

Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com>





      reply	other threads:[~2025-10-31 13:08 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-30 15:55 Martin Kaiser
2025-10-31  2:32 ` Andrew Morton
2025-10-31 10:22   ` Martin Kaiser
2025-10-31 13:08     ` Liam R. Howlett [this message]

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