Re: [RFC] ARM binutils feature churn causing kernel problems

Paulo Marques
2004-10-07T12:47:00Z

Rusty Russell wrote:
> On Tue, 2004-10-05 at 23:14, Russell King wrote:
>
>>On Tue, Oct 05, 2004 at 01:57:15PM +0100, Richard Earnshaw wrote:
>>
>>>Why don't you pass s to is_arm_mapping_symbol and have it do the same
>>>thing as you've done in get_ksymbol?
>>
>>"sym_entry" is not an ELF symtab structure - it's a parsed version
>>of the `nm' output, and as such does not contain the symbol type nor
>>binding information.
>
>
> I believe that Paulo (CC'd) ended up with a patch which included the
> actual type information in /proc/kallsyms. Paulo, what's the status of
> that patch?

That patch is in the -mm tree, and has been there for a while, so it is
pretty much stable by now. There were 4 seperate patches, but since they
were pretty much dependant, I think akpm merged them into
"kallsyms-data-size-reduction--lookup-speedup.patch".

For those who don't know what the patch is about, it changes the format
of the compressed kallsyms, so that they occupy less space, decompress
faster (a lot faster) and include the same type char that was output by nm.

The code in kernel/kallsyms.c handles "aliases" (symbols with the same
address) in a way that it shows a consistent output: the symbol shown is
always the first. This can be easily changed, but I didn't want to
change the old behavior.

The patch by Russel King seems ok to me, although I prefer Rusty's idea
of not using any symbol that is not in the form "[A-Za-z0-9_]+". We just
need to check if there are any real world users of these "weird" symbols.

If this seems ok to everyone I can cook up a patch to do this.

--
Paulo Marques - www.grupopie.com

To err is human, but to really foul things up requires a computer.
Farmers' Almanac, 1978