On Wed, Oct 16, 2019 at 02:37:10PM +0100, Matthias Maennich wrote: > On Wed, Oct 16, 2019 at 12:50:30PM +0000, Luis Chamberlain wrote: > > On Mon, Oct 14, 2019 at 03:44:40PM +0100, Matthias Maennich wrote: > > > Hi Luis! > > > > > > On Mon, Oct 14, 2019 at 08:52:35AM +0000, Luis Chamberlain wrote: > > > > On Fri, Oct 11, 2019 at 09:26:05PM +0200, Heiner Kallweit wrote: > > > > > On 10.10.2019 19:15, Luis Chamberlain wrote: > > > > > > > > > > > > > > > > > > On Thu, Oct 10, 2019, 6:50 PM Heiner Kallweit <hkallwe...@gmail.com > > > > > > <mailto:hkallwe...@gmail.com>> 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 > > > > > > > > Can you have your user with issues either revert 8651ec01daed or apply > > > > the fixes > > > > mentioned by Matthias to see if that was the issue? > > > > > > > > Matthias what module did you run into which let you run into the issue > > > > with depmod? I ask as I think it would be wise for us to add a test case > > > > using lib/test_kmod.c and tools/testing/selftests/kmod/kmod.sh for the > > > > regression you detected. > > > > > > The depmod warning can be reproduced when using a symbol that is built > > > into vmlinux and used from a module. E.g. with CONFIG_USB_STORAGE=y and > > > CONFIG_USB_UAS=m, the symbol `usb_stor_adjust_quirks` is built in with > > > namespace USB_STORAGE and depmod stumbles upon this emitting the > > > following warning (e.g. during make modules_install). > > > > > > depmod: WARNING: [...]/uas.ko needs unknown symbol usb_stor_adjust_quirks > > > > > > As there is another (less intrusive) way of implementing the namespace > > > feature, I posted a patch series [1] on last Thursday that should > > > mitigate the issue as the ksymtab entries depmod eventually relies on > > > are no longer carrying the namespace in their names. > > > > > > Cheers, > > > Matthias > > > > > > [1] > > > https://lore.kernel.org/lkml/20191010151443.7399-1-maenn...@google.com/ > > > > Yes but kmalloc() is built-in, and used by *all* drivers compiled as > > modules, so why was that an issue? > > I believe you meant, "why was that *not* an issue?".
Right. > In ksymtab, namespaced symbols had the format > > __ksymtab_<NAMESPACE>.<symbol> > > while symbols without namespace would still use the old format > > __ksymtab_<symbol> Ah, I didn't see the symbol namespace patches, good stuff! > These are also the names that are extracted into System.map (using > scripts/mksysmap). Depmod is reading the System.map and for symbols used > by modules that are in a namespace, it would not find a match as it does > not understand the namespace notation. Depmod would still not emit a > warning for symbols without namespace as their format did not change. Can we have a test case for this to ensure we don't regress on this again? Or put another way, what test cases were implemented for symbol namespaces? Luis
