Re: [PATCH v2 04/27] locking/atomic: make atomic*_{cmp,}xchg optional

From: Guenter Roeck
Date: Sat Jul 08 2023 - 09:20:24 EST


On 7/8/23 06:07, Linux regression tracking (Thorsten Leemhuis) wrote:
On 27.06.23 19:07, Guenter Roeck wrote:
On Mon, Jun 05, 2023 at 08:01:01AM +0100, Mark Rutland wrote:
Most architectures define the atomic/atomic64 xchg and cmpxchg
operations in terms of arch_xchg and arch_cmpxchg respectfully.

Add fallbacks for these cases and remove the trivial cases from arch
code. On some architectures the existing definitions are kept as these
are used to build other arch_atomic*() operations.

Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
[...]

This patch results in:

ERROR: modpost: "__xchg_called_with_bad_pointer" [lib/atomic64_test.ko] undefined!

when trying to build sparc64:allmodconfig.

Guenter, please correct me if I'm wrong:

This is fixed by Arnd's patch "sparc: mark __arch_xchg() as
__always_inline", but that afaics sadly hasn't even reached -next yet.
https://lore.kernel.org/all/20230628094938.2318171-1-arnd@xxxxxxxxxx/

Hence adding it to the tracking now that the end of the merge window is
near:

#regzbot ^introduced d12157efc8e083c7
#regzbot title locking/atomic: build error on sparc64:allmodconfig
#regzbot ignore-activity


Yes, this is correct.

Guenter