MIPS + clang-11 + allnoconfig / tinyconfig builds failed

From: Naresh Kamboju
Date: Thu Dec 10 2020 - 12:19:28 EST


Recently we have setup clang build and found that,
MIPS + clang-11 + allnoconfig build failed
MIPS + clang-11 + tinyconfig build failed

MIPS + clang-10 + allnoconfig build failed
MIPS + clang-10 + tinyconfig build failed

We have noticed these build failures on
- stable-4.19
- stable-5.4
- stable-5.9
- mainline
- next-master

FYI, The defconfig builds are successful.
BTW, May I know what are the configs you build often ?

Steps to reproduce build failure:
-----------------------------------------
# sudo pip3 install -U tuxmake
# tuxmake --runtime docker --target-arch mips --toolchain clang-11
--kconfig allnoconfig
# tuxmake --runtime docker --target-arch mips --toolchain clang-11
--kconfig tinyconfig

Build failed log:
ake --silent --keep-going --jobs=16
O=/home/tuxbuild/.cache/tuxmake/builds/2/tmp ARCH=mips
CROSS_COMPILE=mips-linux-gnu- 'HOSTCC=sccache clang' 'CC=sccache
clang' allnoconfig
make --silent --keep-going --jobs=16
O=/home/tuxbuild/.cache/tuxmake/builds/2/tmp ARCH=mips
CROSS_COMPILE=mips-linux-gnu- 'HOSTCC=sccache clang' 'CC=sccache
clang'
/builds/1kl9SVppm6wRdzlQ3UcQKIBaUrx/arch/mips/vdso/elf.S:14:1:
warning: DWARF2 only supports one section per compilation unit
.pushsection .note.Linux, "a",@note ; .balign 4 ; .long 2f - 1f ;
.long 4484f - 3f ; .long 0 ; 1:.asciz "Linux" ; 2:.balign 4 ; 3:
^
/builds/1kl9SVppm6wRdzlQ3UcQKIBaUrx/arch/mips/vdso/elf.S:34:2:
warning: DWARF2 only supports one section per compilation unit
.section .mips_abiflags, "a"
^
/builds/1kl9SVppm6wRdzlQ3UcQKIBaUrx/arch/mips/lib/uncached.c:45:6:
warning: variable 'sp' is uninitialized when used here
[-Wuninitialized]
if (sp >= (long)CKSEG0 && sp < (long)CKSEG2)
^~
/builds/1kl9SVppm6wRdzlQ3UcQKIBaUrx/arch/mips/lib/uncached.c:40:18:
note: initialize the variable 'sp' to silence this warning
register long sp __asm__("$sp");
^
= 0
1 warning generated.
WARNING: modpost: vmlinux.o(.text+0x1a124): Section mismatch in
reference from the function r4k_cache_init() to the function
.init.text:loongson3_sc_init()
The function r4k_cache_init() references
the function __init loongson3_sc_init().
This is often because r4k_cache_init lacks a __init
annotation or the annotation of loongson3_sc_init is wrong.
WARNING: modpost: vmlinux.o(.text+0x1f1c8): Section mismatch in
reference from the function mips_sc_init() to the function
.init.text:mips_sc_probe()
The function mips_sc_init() references
the function __init mips_sc_probe().
This is often because mips_sc_init lacks a __init
annotation or the annotation of mips_sc_probe is wrong.
FATAL: modpost: Section mismatches detected.
Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.
make[2]: *** [/builds/1kl9SVppm6wRdzlQ3UcQKIBaUrx/scripts/Makefile.modpost:59:
vmlinux.symvers] Error 1

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