Following build warnings noticed while building stable-rc Linux 5.14.1-rc1 with gcc-11 for arm64 architecture.

aarch64-linux-gnu-gcc -I../../../../../usr/include/ udmabuf.c -o kselftest/drivers/dma-buf/udmabuf udmabuf.c: In function 'main': udmabuf.c:30:17: warning: implicit declaration of function 'open'; did you mean 'popen'? [-Wimplicit-function-declaration] 30 | devfd = open(/dev/udmabuf, O_RDWR); | ^~~~ | popen udmabuf.c:42:15: warning: implicit declaration of function 'fcntl' [-Wimplicit-function-declaration] 42 | ret = fcntl(memfd, F_ADD_SEALS, F_SEAL_SHRINK); | ^~~~~ make[3]: Leaving directory '/builds/linux/tools/testing/selftests/drivers/dma-buf'

Build config: https://builds.tuxbuild.com/1xXcUtI2INra8KaHjOXXQMOyAD0/config

Reported-by: Linux Kernel Functional Testing lkft@linaro.org

meta data: ----------- git_describe: v5.14-rc6-389-g95dc72bb9c03, git_repo: https://gitlab.com/Linaro/lkft/mirrors/stable/linux-stable-rc, git_sha: 95dc72bb9c032093e79e628a98c927b3db73a6c3, git_short_log: 95dc72bb9c03 (\Linux 5.14.1-rc1), kconfig: [ defconfig, https://raw.githubusercontent.com/Linaro/meta-lkft/sumo/recipes-kernel/linux..., https://raw.githubusercontent.com/Linaro/meta-lkft/sumo/recipes-kernel/linux..., https://raw.githubusercontent.com/Linaro/meta-lkft/sumo/recipes-kernel/linux..., https://raw.githubusercontent.com/Linaro/meta-lkft/sumo/recipes-kernel/linux..., https://raw.githubusercontent.com/Linaro/meta-lkft/sumo/recipes-kernel/linux..., CONFIG_ARM64_MODULE_PLTS=y ], kernel_version: 5.14.1-rc1, target_arch: arm64, targets: [ dtbs, dtbs-legacy, headers, kernel, kselftest, kselftest-merge, modules ], toolchain: gcc-11,

steps to reproduce: https://builds.tuxbuild.com/1xXcUtI2INra8KaHjOXXQMOyAD0/tuxmake_reproducer.s...

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