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Date: Mon, 24 Mar 2025 13:36:19 -0400
From: Steven Rostedt <rostedt@goodmis.org>
To: Sahil Gupta <s.gupta@arista.com>
Cc: linux-trace-kernel@vger.kernel.org, Kevin Mitchell
 <kevmitch@arista.com>, Dmitry Safonov <dima@arista.com>
Subject: Re: ftrace: sorttable unable to sort ELF64 on 32-bit host
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On Thu, 20 Mar 2025 16:54:58 -0500
Sahil Gupta <s.gupta@arista.com> wrote:

> Hi Steven,
> 
> On 6.12.0, sorttable is unable to sort 64-bit ELFs on 32-bit hosts because
> of the parsing of the start_mcount_loc and stop_mcount_loc values in
> get_mcount_loc():
> 
>   *_start = strtoul(start_buff, NULL, 16);
> 
> and
> 
>  *_stop = strtoul(stop_buff, NULL, 16);
> 
> This code makes the (often correct) assumption that the host and the target
> have the same architecture, however it runs into issues when compiling for
> a 64-bit target on a 32-bit host, as unsigned long is shorter than the
> pointer width. As a result, I've noticed that both start and stop max out
> at 2^32 - 1.

So this has been broken for some time?

> 
> It seems that commit 4acda8ed fixes this issue inadvertently by directly
> extracting them from the ELF using the correct width. I'm wondering if it
> is possible to backport this as well as the other sorttable refactors to
> 6.12.0 since they fix this issue.

You should ask Greg KH on this.

-- Steve