Re: linux-next: build failure after merge of the printk tree

From: Petr Mladek
Date: Fri Mar 02 2018 - 10:55:17 EST


On Fri 2018-03-02 16:07:32, Stephen Rothwell wrote:
> Hi Petr,
>
> After merging the printk tree, today's linux-next build (bfin
> BF518F-EZBRD_defconfig) failed like this:
>
> lib/dump_stack.o: In function `dump_stack':
> lib/dump_stack.c:122: multiple definition of `dump_stack'
> arch/blackfin/kernel/dumpstack.o:arch/blackfin/kernel/dumpstack.c:166: first defined here
>
> Presumably caused by commit
>
> 8040af489957 ("printk: move dump stack related code to lib/dump_stack.c")

I could confirm that it is caused by this commit. I have temporary
removed it from printk.git.

> (Though it is not immediately obvious why.)

It is a mistery to me. The error appears when I move any of
dump_stack_print_info() or show_regs_print_info() function
definitions from kernel/printk/printk.c to lib/dump_stack.c.
All the other changes seems unrelated.

The thing is that we basically do not touch dump_stack() definition
by that patch.

> This fails all the blackfin builds. nds32 (a new architecture) also
> has a dump_stack function.

Good to know!

Best Regards,
Petr