Re: [PATCH] libkmod-elf: resolve CRC if module is built with MODULE_REL_CRCS

From: Yauheni Kaliuta
Date: Wed Jul 19 2017 - 15:01:20 EST


Hi, Lucas!

>>>>> On Wed, 19 Jul 2017 10:51:44 -0700, Lucas De Marchi wrote:
> On Wed, Jul 19, 2017 at 7:56 AM, Yauheni Kaliuta
> <yauheni.kaliuta@xxxxxxxxxx> wrote:
>> Normally exported symbol's crc is stored as absolute (SHN_ABS)
>> value of special named symbol __crc_<symbol name>.
>>
>> When the kernel and modules are built with the config option
>> CONFIG_MODULE_REL_CRCS, all the CRCs are put in a special section
>> and the __crc_<symbol name> symbols values are offsets in the
>> section. See patch description of the commit:
>>
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=56067812d5b0e737ac2063e94a50f76b810d6ca3
>>
>> Add kmod support of this configuration.

[...]

> LGTM. I'll give this a try and apply.

Thanks! I would also like to get some feedback from the kernel feature
author, Ard Biesheuvel, that this does not miss other usecases.

> Do you think it's possible to build an out-of-tree module with this
> option so we can add one to the testsuite?

I'll check what I can do.

The problem is seen if you run depmod with -e -E, which I guess is not used
too often.

--
WBR,
Yauheni Kaliuta