selftests: vDSO: look for arch-specific function name in getrandom test

Don't hard-code x86 specific names. Rather, use vdso_config definitions
to find the correct function matching the architecture.

Add random VDSO function names in names[][]. Remove the #ifdef
CONFIG_VDSO32, as having the name there all the time is harmless and
guaranties a steady index for following strings.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[Jason: add [6] to variable declaration rather than each usage site.]
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

tools/testing/selftests/vDSO/vdso_config.h

@@ -68,16 +68,15 @@ static const char *versions[7] = {
 	"LINUX_5.10"
 };
 
-static const char *names[2][6] = {
+static const char *names[2][7] = {
 	{
 		"__kernel_gettimeofday",
 		"__kernel_clock_gettime",
 		"__kernel_time",
 		"__kernel_clock_getres",
 		"__kernel_getcpu",
-#if defined(VDSO_32BIT)
 		"__kernel_clock_gettime64",
-#endif
+		"__kernel_getrandom",
 	},
 	{
 		"__vdso_gettimeofday",
@@ -85,9 +84,8 @@ static const char *names[2][6] = {
 		"__vdso_time",
 		"__vdso_clock_getres",
 		"__vdso_getcpu",
-#if defined(VDSO_32BIT)
 		"__vdso_clock_gettime64",
-#endif
+		"__vdso_getrandom",
 	},
 };
 

tools/testing/selftests/vDSO/vdso_test_getrandom.c

@@ -21,6 +21,7 @@
 
 #include "../kselftest.h"
 #include "parse_vdso.h"
+#include "vdso_config.h"
 
 #ifndef timespecsub
 #define	timespecsub(tsp, usp, vsp)					\
@@ -100,15 +101,18 @@ static void vgetrandom_put_state(void *state)
 
 static void vgetrandom_init(void)
 {
+	const char *version = versions[VDSO_VERSION];
+	const char *name = names[VDSO_NAMES][6];
 	unsigned long sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR);
+
 	if (!sysinfo_ehdr) {
 		printf("AT_SYSINFO_EHDR is not present!\n");
 		exit(KSFT_SKIP);
 	}
 	vdso_init_from_sysinfo_ehdr(sysinfo_ehdr);
-	vgrnd.fn = (__typeof__(vgrnd.fn))vdso_sym("LINUX_2.6", "__vdso_getrandom");
+	vgrnd.fn = (__typeof__(vgrnd.fn))vdso_sym(version, name);
 	if (!vgrnd.fn) {
-		printf("__vdso_getrandom is missing!\n");
+		printf("%s is missing!\n", name);
 		exit(KSFT_FAIL);
 	}
 	if (vgrnd.fn(NULL, 0, 0, &vgrnd.params, ~0UL) != 0) {