Commit f0ff2447b861 ("selftests/sgx: Add a new kselftest: Unclobbered_vdso_oversubscribed") depends on __cpuid() without providing the dependency and thus introduces a build error:
$ make gcc -Wall -Werror -g -I../../../../tools/include -fPIC -z noexecstack -c main.c -o ../linux/tools/testing/selftests/sgx/main.o main.c: In function ‘get_total_epc_mem’: main.c:296:3: error: implicit declaration of function ‘__cpuid’ [-Werror=implicit-function-declaration] 296 | __cpuid(&eax, &ebx, &ecx, &edx); | ^~~~~~~ cc1: all warnings being treated as errors make: *** [Makefile:33: ../linux/tools/testing/selftests/sgx/main.o] Error 1 $
Clone kernel's __cpuid() implementation to the self-test in order to make it available to the EPC enumeration code.
Fixes: f0ff2447b861 ("selftests/sgx: Add a new kselftest: Unclobbered_vdso_oversubscribed") Reported-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com ---
The commit introducing the issue can be found on the x86/sgx branch of tip.git.
Changes since V1: - V1: https://lore.kernel.org/linux-sgx/797ff1331cfe540fc378fcc4a4a7b00ff5099fbe.1... - Improve commit message. (Jarkko)
tools/testing/selftests/sgx/main.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c index 7e912db4c6c5..6dead57a3121 100644 --- a/tools/testing/selftests/sgx/main.c +++ b/tools/testing/selftests/sgx/main.c @@ -73,6 +73,18 @@ static bool vdso_get_symtab(void *addr, struct vdso_symtab *symtab) return true; }
+static inline void __cpuid(unsigned int *eax, unsigned int *ebx, + unsigned int *ecx, unsigned int *edx) +{ + asm volatile("cpuid" + : "=a" (*eax), + "=b" (*ebx), + "=c" (*ecx), + "=d" (*edx) + : "0" (*eax), "2" (*ecx) + : "memory"); +} + static unsigned long elf_sym_hash(const char *name) { unsigned long h = 0, high;