test_vsyscall.c:500:22: warning: '__builtin_memcmp_eq' specified bound 4096 exceeds source size 0

From: Naresh Kamboju
Date: Thu Jan 06 2022 - 04:26:08 EST


While building selftests the following warnings were noticed for x86_64
architecture on Linux stable v5.15.13 kernel.

metadata:
git repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
git commit: 734eb1fd2073f503f5c6b44f1c0d453ca6986b84
git describe: v5.15.13
toolchain": gcc-11
kernel-config: https://builds.tuxbuild.com/23HFo8abXIL6i4FFfSYiJlqAYMW/config

x86_64-linux-gnu-gcc -m64 -o \
/home/tuxbuild/.cache/tuxmake/builds/current/kselftest/x86/test_vsyscall_64 \
-O2 -g -std=gnu99 -pthread -Wall -no-pie \
-DCAN_BUILD_64 test_vsyscall.c helpers.h -lrt -ldl

test_vsyscall.c: In function 'test_process_vm_readv':
test_vsyscall.c:500:22: warning: '__builtin_memcmp_eq' specified bound
4096 exceeds source size 0 [-Wstringop-overread]
500 | if (!memcmp(buf, (const void
*)0xffffffffff600000, 4096)) {
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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

Build link:
https://builds.tuxbuild.com/23HFo8abXIL6i4FFfSYiJlqAYMW/

# To install tuxmake on your system globally:
# sudo pip3 install -U tuxmake

tuxmake --runtime podman --target-arch x86_64 --toolchain gcc-11 \
--kconfig https://builds.tuxbuild.com/23HFo8abXIL6i4FFfSYiJlqAYMW/config \
cpupower headers kernel kselftest kselftest-merge modules


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