Messages in this thread |  | | | Date | Mon, 14 Mar 2005 13:33:47 +0000 | | From | Paulo Marques <> | | Subject | Re: inconsistent kallsyms data [2.6.11-mm2] |
| |
Sam Ravnborg wrote: > On Thu, Mar 10, 2005 at 12:12:22PM +0000, Paulo Marques wrote: > >>Paulo Marques wrote: >> >>>[...] >>>A simple and robust way is to do the sampling on a list of symbols >>>sorted by symbol name. This way, even if the symbol positions that are >>>given to scripts/kallsyms change, the symbols sampled will be the same. >>> >>>I'll do the patch to do this and send it ASAP. >> >>Ok, here it is. >> >>Dominik can you try the attached patch and see if it solves the problem? > > Hi Paulo.
Hi Sam :)
> Alexander Stohr had similar problems with down and __sched_text_start. > > I figured out that what was causing the troubles was the fact that the > linker generated symbol __sched_text_start changed value from pass 1 to > pass 2. The reason for this was the alingment used within that section.
Damn, you're right. Looking more carefully at Dominik's files I can see that on the first pass we have:
T __sched_text_start PTR 0xc0420482 t __down PTR 0xc0420484
and on the second pass:
t __down PTR 0xc0420484 T __sched_text_start PTR 0xc0420484
I only looked at the addresses on the second pass and noticed they were aliased symbols and that the symbol order changed from the first pass :P
> I never came around submitting this since I do not know what the correct > number for function alignment is on different paltforms.
If this will just align the beginning of a section, I don't think it will be a problem to always align at 8 bytes even on platforms that need only a 4 byte alignment.
So I think that your patch should definitely go in, as it solves a real problem.
As for my patch it could potentially solve problems that we don't currently have(*), so it is probably better to wait for them to appear before trying to solve an non-existent problem :)
-- Paulo Marques - www.grupopie.com
All that is necessary for the triumph of evil is that good men do nothing. Edmund Burke (1729 - 1797)
(*) order of aliased symbols changing, or 'nm' returning non sorted addresses. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |