Recently we have updated toolchain clang-17 version.

While building selftests vdso following warnings / errors noticed on the Linux next with clang-17. but pass with gcc-13.

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

make[4]: Entering directory 'tools/testing/selftests/vDSO' clang --target=x86_64-linux-gnu -fintegrated-as -Werror=unknown-warning-option -Werror=ignored-optimization-argument -Werror=option-ignored -Werror=unused-command-line-argument --target=x86_64-linux-gnu -fintegrated-as -std=gnu99 -nostdlib -fno-asynchronous-unwind-tables -fno-stack-protector \ vdso_standalone_test_x86.c parse_vdso.c \ -o /vDSO/vdso_standalone_test_x86 vdso_standalone_test_x86.c:73:16: warning: unknown attribute 'externally_visible' ignored [-Wunknown-attributes] 73 | __attribute__((externally_visible)) void c_main(void **stack) | ^~~~~~~~~~~~~~~~~~ 1 warning generated. parse_vdso.c:65:9: warning: using the result of an assignment as a condition without parentheses [-Wparentheses] 65 | if (g = h & 0xf0000000) | ~~^~~~~~~~~~~~~~~~ parse_vdso.c:65:9: note: place parentheses around the assignment to silence this warning 65 | if (g = h & 0xf0000000) | ^ | ( ) parse_vdso.c:65:9: note: use '==' to turn this assignment into an equality comparison 65 | if (g = h & 0xf0000000) | ^ | == parse_vdso.c:206:22: warning: passing 'const char *' to parameter of type 'const unsigned char *' converts between pointers to integer types where one is of the unique plain 'char' type and the other is not [-Wpointer-sign] 206 | ver_hash = elf_hash(version); | ^~~~~~~ parse_vdso.c:59:52: note: passing argument to parameter 'name' here 59 | static unsigned long elf_hash(const unsigned char *name) | ^ parse_vdso.c:207:46: warning: passing 'const char *' to parameter of type 'const unsigned char *' converts between pointers to integer types where one is of the unique plain 'char' type and the other is not [-Wpointer-sign] 207 | ELF(Word) chain = vdso_info.bucket[elf_hash(name) % vdso_info.nbucket]; | ^~~~ parse_vdso.c:59:52: note: passing argument to parameter 'name' here 59 | static unsigned long elf_hash(const unsigned char *name) | ^ 3 warnings generated. /usr/bin/x86_64-linux-gnu-ld: /tmp/vdso_standalone_test_x86-31b09f.o: in function `c_main': vdso_standalone_test_x86.c:(.text+0x1e6): undefined reference to `memcpy' clang: error: linker command failed with exit code 1 (use -v to see invocation) make[4]: Leaving directory 'tools/testing/selftests/vDSO'

Links: - https://storage.tuxsuite.com/public/linaro/lkft/builds/2UHhSg0TPLhjp9Uq9EFce... - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20230821/tes...

Steps to reproduce: - https://storage.tuxsuite.com/public/linaro/lkft/builds/2UHhSg0TPLhjp9Uq9EFce...

tuxmake --runtime podman --target-arch x86_64 --toolchain clang-17 --kconfig https://storage.tuxsuite.com/public/linaro/lkft/builds/2UHhSg0TPLhjp9Uq9EFce... LLVM=1 LLVM_IAS=1 debugkernel cpupower headers kernel kselftest modules

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