Re: linux-next: build warnings after merge of the tip tree

From: Uros Bizjak
Date: Fri Dec 01 2023 - 07:10:03 EST


On Fri, Dec 1, 2023 at 1:29 AM Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
>
> Hi all,
>
> After merging the tip tree, today's linux-next build (x86_64 allmodconfig)
> produced these warnings:
>
> WARNING: modpost: EXPORT symbol "const_pcpu_hot" [vmlinux] version generation failed, symbol will not be versioned.
> Is "const_pcpu_hot" prototyped in <asm/asm-prototypes.h>?
> WARNING: modpost: "const_pcpu_hot" [arch/x86/kernel/msr.ko] has no CRC!
> WARNING: modpost: "const_pcpu_hot" [arch/x86/kvm/kvm.ko] has no CRC!

My build doesn't produce any warnings. A defconfig + enabling kvm.ko as module:

...
AR built-in.a
AR vmlinux.a
LD vmlinux.o
OBJCOPY modules.builtin.modinfo
GEN modules.builtin
MODPOST Module.symvers
CC .vmlinux.export.o
CC [M] arch/x86/kvm/kvm.mod.o
CC [M] fs/efivarfs/efivarfs.mod.o
...

Does the attached patch help? Or is there anything else I should do to
trigger the above problem?

Thanks,
Uros.
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 4d4b87c6885d..1277d4e0aa42 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -2056,7 +2056,7 @@ DEFINE_PER_CPU_ALIGNED(struct pcpu_hot, pcpu_hot) = {
.top_of_stack = TOP_OF_INIT_STACK,
};
EXPORT_PER_CPU_SYMBOL(pcpu_hot);
-EXPORT_PER_CPU_SYMBOL(const_pcpu_hot);
+EXPORT_SYMBOL(const_pcpu_hot);

#ifdef CONFIG_X86_64
DEFINE_PER_CPU_FIRST(struct fixed_percpu_data,