Messages in this thread | | | Date | Wed, 04 Apr 2018 12:54:08 -0400 (EDT) | Subject | Re: [PATCH] netdevsim: remove incorrect __net_initdata annotations | From | David Miller <> |
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From: Arnd Bergmann <arnd@arndb.de> Date: Wed, 4 Apr 2018 18:03:41 +0200
> On Wed, Apr 4, 2018 at 5:52 PM, David Miller <davem@davemloft.net> wrote: >> From: Arnd Bergmann <arnd@arndb.de> >> Date: Wed, 4 Apr 2018 14:12:39 +0200 >> >>> The __net_initdata section cannot currently be used for structures that >>> get cleaned up in an exitcall using unregister_pernet_operations: >>> >>> WARNING: vmlinux.o(.text+0x868c34): Section mismatch in reference from the function nsim_devlink_exit() to the (unknown reference) .init.data:(unknown) >>> The function nsim_devlink_exit() references >>> the (unknown reference) __initdata (unknown). >>> This is often because nsim_devlink_exit lacks a __initdata >>> annotation or the annotation of (unknown) is wrong. >>> WARNING: vmlinux.o(.text+0x868c64): Section mismatch in reference from the function nsim_devlink_init() to the (unknown reference) .init.data:(unknown) >>> WARNING: vmlinux.o(.text+0x8692bc): Section mismatch in reference from the function nsim_fib_exit() to the (unknown reference) .init.data:(unknown) >>> WARNING: vmlinux.o(.text+0x869300): Section mismatch in reference from the function nsim_fib_init() to the (unknown reference) .init.data:(unknown) >>> >>> As that warning tells us, discarding the structure after a module is >>> loaded would lead to a undefined behavior when that module is removed. >>> >>> It might be possible to change that annotation so it has no effect for >>> loadable modules, but I have not figured out exactly how to do that, and >>> we want this to be fixed in -rc1. >>> >>> This just removes the annotations, just like we do for all other such >>> modules. >>> >>> Fixes: 37923ed6b8ce ("netdevsim: Add simple FIB resource controller via devlink") >>> Signed-off-by: Arnd Bergmann <arnd@arndb.de> >> >> Hmmm... >> >> __net_initdata defines to nothing if network namespaces are enabled. >> >> That's the whole point. >> >> Therefore, if NETNS is disabled, "unregister_pernet_operations" cannot >> happen and this is the only time when __net_initdata actually does >> something. > > The problem happens with CONFIG_NETNS=n: __net_initdata turns into > __initdata, and nsim_fib_net_ops is referenced from a function that is > not marked __init (i.e. nsim_fib_exit). > > The logic to turn __net_initdata into __init only makes sense for > subsystems that have no way to be unregistered, i.e. code which is > always built-in, or non-unloadable modules.
Ok, I see it.
I'll apply this for now, thanks.
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