[PATCH 3/3] Revert "hardening: Disable GCC randstruct for COMPILE_TEST"

[Kees Cook]

On Thu, May 29, 2025 at 09:06:46PM -0300, Thiago Jung Bauermann wrote:
> This commit was reported by our CI as breaking the allmodconfig build for
> the arm and arm64 architectures when using GCC 15. This is due to
> https://github.com/KSPP/linux/issues/367 :
> 
> 00:05:08 arch/arm64/kernel/kexec_image.c:132:14: internal compiler error: in comptypes_check_enum_int, at c/c-typeck.cc:1519
> 00:05:08   132 | const struct kexec_file_ops kexec_image_ops = {
> 00:05:08       |              ^~~~~~~~~~~~~~

I'm not able to reproduce this. Which specific version of GCC 15 and
on what distro are you seeing this?

This is Fedora 42 for me:

$ aarch64-linux-gnu-gcc --version
aarch64-linux-gnu-gcc (GCC) 15.1.1 20250425 (Red Hat Cross 15.1.1-1)
...
$ make O=gcc-arm64 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- allmodconfig
$ grep RANDSTRUCT gcc-arm64/.config
# CONFIG_RANDSTRUCT_NONE is not set
CONFIG_RANDSTRUCT_FULL=y
# CONFIG_RANDSTRUCT_PERFORMANCE is not set
CONFIG_RANDSTRUCT=y
CONFIG_GCC_PLUGIN_RANDSTRUCT=y
CONFIG_RANDSTRUCT_KUNIT_TEST=m
$ make O=gcc-arm64 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- all -s
$ file gcc-arm64/vmlinux
gcc-arm64/vmlinux: ELF 64-bit LSB pie executable, ARM aarch64, version 1 (SYSV), statically linked, BuildID[sha1]=b53656cb73bb82f4e19edbfa54241c203daa3fed, not stripped


And the new KUnit randstruct selftests all pass as well:

$ ./tools/testing/kunit/kunit.py run \
	--arch arm64 --cross_compile aarch64-linux-gnu- \
	--kconfig_add CONFIG_RANDSTRUCT_FULL=y randstruct
...
# Totals: pass:5 fail:0 skip:0 total:5



-- 
Kees Cook