Re: Module loading problem since 5.3

From: Jessica Yu
Date: Mon Oct 14 2019 - 06:01:51 EST


+++ Heiner Kallweit [11/10/19 21:26 +0200]:
On 10.10.2019 19:15, Luis Chamberlain wrote:


On Thu, Oct 10, 2019, 6:50 PM Heiner Kallweit <hkallweit1@xxxxxxxxx <mailto:hkallweit1@xxxxxxxxx>> wrote:

   MODULE_SOFTDEP("pre: realtek")

Are you aware of any current issues with module loading
that could cause this problem?


Nope. But then again I was not aware of MODULE_SOFTDEP(). I'd encourage an extension to lib/kmod.c or something similar which stress tests this. One way that comes to mind to test this is to allow a new tests case which loads two drives which co depend on each other using this macro. That'll surely blow things up fast. That is, the current kmod tests uses request_module() or get_fs_type(), you'd want a new test case with this added using then two new dummy test drivers with the macro dependency.

If you want to resolve this using a more tested path, you could have request_module() be used as that is currently tested. Perhaps a test patch for that can rule out if it's the macro magic which is the issue.

  Luis

Maybe issue is related to a bug in introduction of symbol namespaces, see here:
https://lkml.org/lkml/2019/10/11/659

If you're running into depmod and module loading issues with kernels >=5.3-rc1,
it's likely due to the namespaces patchset and we're working on
getting all the kinks fixed. Could you please ask the bug reporter to
try the latest -rc kernel with these set of fixes applied on top?

https://lore.kernel.org/linux-modules/20191010151443.7399-1-maennich@xxxxxxxxxx/

They fix a known depmod issue caused by our __ksymtab naming scheme,
which is being reverted in favor of extracting the namespace from
__kstrtabns and __ksymtab_strings. These fixes will be in by -rc4.

Thanks,

Jessica