Re: ftrace: sorttable unable to sort ELF64 on 32-bit host

[Steven Rostedt <rostedt@goodmis.org>]

On Thu, 20 Mar 2025 17:02:06 -0500
Sahil Gupta <s.gupta@arista.com> wrote:

> Hi Steven,

Hi,

Sorry for the really late reply. I'm cleaning out my inbox and just noticed
this email.

> 
> 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.
> 
> 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.

I think this is a good reason to mark that commit as stable and backport it
to 6.12.

-- Steve