Hi Jeff,
On Tue, Jul 9, 2024 at 1:58 PM Jeff Layton <jlayton@xxxxxxxxxx> wrote:
I've been getting some of these warning emails from the KTR. I think
this is in reference to this patch, which adds a 64-bit try_cmpxchg in
the timestamp handling code:
https://lore.kernel.org/linux-fsdevel/20240708-mgtime-v4-0-a0f3c6fb57f3@xxxxxxxxxx/
On m68k, there is a prototype for __invalid_cmpxchg_size, but no actual
function, AFAICT. Should that be defined somewhere, or is this a
deliberate way to force a build break in this case?
It's a deliberate way to break the build.
More to the point though: do I need to do anything special for m86k
here (or for other arches that can't do a native 64-bit cmpxchg)?
64-bit cmpxchg() is only guaranteed to exist on 64-bit platforms.
See also
https://elixir.bootlin.com/linux/latest/source/include/asm-generic/cmpxchg.h#L62
I think you can use arch_cmpxchg64(), though.
---------- Forwarded message ----------
From: kernel test robot <lkp@xxxxxxxxx>
m68k-linux-ld: fs/inode.o: in function `inode_set_ctime_current':
inode.c:(.text+0x167a): undefined reference to `__invalid_cmpxchg_size'
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
