selftests/vDSO: fix runtime errors on LoongArch

It could not find __vdso_getcpu and __vdso_gettimeofday when test getcpu
and gettimeofday on LoongArch.

  # make headers && cd tools/testing/selftests/vDSO && make
  # ./vdso_test_getcpu
  Could not find __vdso_getcpu
  # ./vdso_test_gettimeofday
  Could not find __vdso_gettimeofday

One simple way is to add LoongArch case to define version and name, just
like commit d942f23 ("selftests/vDSO: Add riscv getcpu & gettimeofday
test"), but it is not the best way.

Since each architecture has already defined names and versions in
vdso_config.h, it is proper to include vdso_config.h to get version and
name for all archs.

Link: https://lkml.kernel.org/r/20240428030530.24399-3-yangtiezhu@loongson.cn
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: seehearfeel

tools/testing/selftests/vDSO/vdso_test_getcpu.c

@@ -13,20 +13,16 @@
 
 #include "../kselftest.h"
 #include "parse_vdso.h"
-
-#if defined(__riscv)
-const char *version = "LINUX_4.15";
-#else
-const char *version = "LINUX_2.6";
-#endif
-const char *name = "__vdso_getcpu";
+#include "vdso_config.h"
 
 struct getcpu_cache;
 typedef long (*getcpu_t)(unsigned int *, unsigned int *,
 			 struct getcpu_cache *);
 
 int main(int argc, char **argv)
 {
+	const char *version = versions[VDSO_VERSION];
+	const char **name = (const char **)&names[VDSO_NAMES];
 	unsigned long sysinfo_ehdr;
 	unsigned int cpu, node;
 	getcpu_t get_cpu;
@@ -40,17 +36,17 @@ int main(int argc, char **argv)
 
 	vdso_init_from_sysinfo_ehdr(getauxval(AT_SYSINFO_EHDR));
 
-	get_cpu = (getcpu_t)vdso_sym(version, name);
+	get_cpu = (getcpu_t)vdso_sym(version, name[4]);
 	if (!get_cpu) {
-		printf("Could not find %s\n", name);
+		printf("Could not find %s\n", name[4]);
 		return KSFT_SKIP;
 	}
 
 	ret = get_cpu(&cpu, &node, 0);
 	if (ret == 0) {
 		printf("Running on CPU %u node %u\n", cpu, node);
 	} else {
-		printf("%s failed\n", name);
+		printf("%s failed\n", name[4]);
 		return KSFT_FAIL;
 	}
 

tools/testing/selftests/vDSO/vdso_test_gettimeofday.c

@@ -18,25 +18,13 @@
 
 #include "../kselftest.h"
 #include "parse_vdso.h"
-
-/*
- * ARM64's vDSO exports its gettimeofday() implementation with a different
- * name and version from other architectures, so we need to handle it as
- * a special case.
- */
-#if defined(__aarch64__)
-const char *version = "LINUX_2.6.39";
-const char *name = "__kernel_gettimeofday";
-#elif defined(__riscv)
-const char *version = "LINUX_4.15";
-const char *name = "__vdso_gettimeofday";
-#else
-const char *version = "LINUX_2.6";
-const char *name = "__vdso_gettimeofday";
-#endif
+#include "vdso_config.h"
 
 int main(int argc, char **argv)
 {
+	const char *version = versions[VDSO_VERSION];
+	const char **name = (const char **)&names[VDSO_NAMES];
+
 	unsigned long sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR);
 	if (!sysinfo_ehdr) {
 		printf("AT_SYSINFO_EHDR is not present!\n");
@@ -47,10 +35,10 @@ int main(int argc, char **argv)
 
 	/* Find gettimeofday. */
 	typedef long (*gtod_t)(struct timeval *tv, struct timezone *tz);
-	gtod_t gtod = (gtod_t)vdso_sym(version, name);
+	gtod_t gtod = (gtod_t)vdso_sym(version, name[0]);
 
 	if (!gtod) {
-		printf("Could not find %s\n", name);
+		printf("Could not find %s\n", name[0]);
 		return KSFT_SKIP;
 	}
 
@@ -61,7 +49,7 @@ int main(int argc, char **argv)
 		printf("The time is %lld.%06lld\n",
 		       (long long)tv.tv_sec, (long long)tv.tv_usec);
 	} else {
-		printf("%s failed\n", name);
+		printf("%s failed\n", name[0]);
 		return KSFT_FAIL;
 	}