next-20250616: S390 gcc-8 allnoconfig mm mempool.c In function remove_element

[Naresh Kamboju]

Regression while building S390 with the Linux next-20250616
with gcc-8 the following kernel warnings found.

Regressions found on S390
 -  build/gcc-8-lkftconfig-allnoconfig
 -  build/gcc-8-lkftconfig-hardening

Regression Analysis:
 - New regression? Yes
 - Reproducibility? Yes

First seen on the next-20250616
Good: next-20250613
Bad:  next-20250616

Build regression: S390 gcc-8 allnoconfig mm mempool.c In function remove_element

Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>

## Build errors
mm/mempool.c: In function 'remove_element':
include/linux/compiler_types.h:497:20: warning: asm operand 0 probably
doesn't match constraints
 #define asm_inline asm __inline
                    ^~~
arch/s390/include/asm/bug.h:12:2: note: in expansion of macro 'asm_inline'
  asm_inline volatile(     \
  ^~~~~~~~~~
arch/s390/include/asm/bug.h:43:2: note: in expansion of macro '__EMIT_BUG'
  __EMIT_BUG("", 0);    \
  ^~~~~~~~~~
include/asm-generic/bug.h:77:57: note: in expansion of macro 'BUG'
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                                         ^~~
mm/mempool.c:149:2: note: in expansion of macro 'BUG_ON'
  BUG_ON(pool->curr_nr < 0);
  ^~~~~~
include/linux/compiler_types.h:497:20: error: impossible constraint in 'asm'
 #define asm_inline asm __inline
                    ^~~

## Source
* Kernel version: 6.16.0-rc2
* Git tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next.git
* Git sha: 050f8ad7b58d9079455af171ac279c4b9b828c11
* Git describe: next-20250616
* Project details:
https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20250616/
* Architectures: S390
* Toolchains: gcc-8
* Kconfigs: allnoconfig

## Build S390
* Build log: https://qa-reports.linaro.org/api/testruns/28763376/log_file/
* Build details:
https://regressions.linaro.org/lkft/linux-next-master/next-20250616/build/gcc-8-allnoconfig/
* Build link: https://storage.tuxsuite.com/public/linaro/lkft/builds/2ya0wQbvgatYAbcvC2OTZls5D91/
* Kernel config:
https://storage.tuxsuite.com/public/linaro/lkft/builds/2ya0wQbvgatYAbcvC2OTZls5D91/config

## Steps to reproduce on S390
 - tuxmake --runtime podman --target-arch s390 --toolchain gcc-8
--kconfig allnoconfig

--
Linaro LKFT
https://lkft.linaro.org