selftests: vDSO: vdso_test_correctness: Use facilities from parse_vdso.c

The soname from the vDSO is not a public API. Furthermore it requires
libc to implement dlsym() and friends.

Use the facilities from parse_vdso.c instead which uses the official
vDSO ABI to find it, aligned with the other vDSO selftests.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20260227-vdso-selftest-cleanups-v2-5-d84830fa8beb@linutronix.de

diff --git a/tools/testing/selftests/vDSO/Makefile b/tools/testing/selftests/vDSO/Makefile
index 2de5cef311c8ab695606cf7f408c04910842e377..a61047bdcd576d47d944f442f9e7140fccfe58e0 100644 (file)
--- a/tools/testing/selftests/vDSO/Makefile
+++ b/tools/testing/selftests/vDSO/Makefile
@@ -26,13 +26,11 @@ CFLAGS_NOLIBC := -nostdlib -nostdinc -ffreestanding -fno-asynchronous-unwind-tab
 $(OUTPUT)/vdso_test_gettimeofday: parse_vdso.c vdso_test_gettimeofday.c
 $(OUTPUT)/vdso_test_getcpu: parse_vdso.c vdso_test_getcpu.c
 $(OUTPUT)/vdso_test_abi: parse_vdso.c vdso_test_abi.c
+$(OUTPUT)/vdso_test_correctness: parse_vdso.c vdso_test_correctness.c
 
 $(OUTPUT)/vdso_standalone_test_x86: vdso_standalone_test_x86.c parse_vdso.c | headers
 $(OUTPUT)/vdso_standalone_test_x86: CFLAGS:=$(CFLAGS_NOLIBC) $(CFLAGS)
 
-$(OUTPUT)/vdso_test_correctness: vdso_test_correctness.c
-$(OUTPUT)/vdso_test_correctness: LDFLAGS += -ldl
-
 $(OUTPUT)/vdso_test_getrandom: parse_vdso.c
 $(OUTPUT)/vdso_test_getrandom: CFLAGS += -isystem $(top_srcdir)/tools/include \
                                          $(KHDR_INCLUDES) \

diff --git a/tools/testing/selftests/vDSO/vdso_test_correctness.c b/tools/testing/selftests/vDSO/vdso_test_correctness.c
index 9b564888e74db6047f33200b1ab7c715e828f592..a94ab4d597b154538a7617a524cccfa7660ca664 100644 (file)
--- a/tools/testing/selftests/vDSO/vdso_test_correctness.c
+++ b/tools/testing/selftests/vDSO/vdso_test_correctness.c
@@ -11,18 +11,20 @@
 #include <time.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <sys/auxv.h>
 #include <sys/syscall.h>
-#include <dlfcn.h>
 #include <string.h>
 #include <errno.h>
 #include <sched.h>
 #include <stdbool.h>
 #include <limits.h>
 
+#include "parse_vdso.h"
 #include "vdso_config.h"
 #include "vdso_call.h"
 #include "kselftest.h"
 
+static const char *version;
 static const char **name;
 
 #ifndef __NR_clock_gettime64
@@ -102,39 +104,32 @@ static void *vsyscall_getcpu(void)
 
 static void fill_function_pointers(void)
 {
-       void *vdso = dlopen("linux-vdso.so.1",
-                           RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
-       if (!vdso)
-               vdso = dlopen("linux-gate.so.1",
-                             RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
-       if (!vdso)
-               vdso = dlopen("linux-vdso32.so.1",
-                             RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
-       if (!vdso)
-               vdso = dlopen("linux-vdso64.so.1",
-                             RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
-       if (!vdso) {
+       unsigned long sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR);
+
+       if (!sysinfo_ehdr) {
                printf("[WARN]\tfailed to find vDSO\n");
                return;
        }
 
-       vdso_getcpu = (getcpu_t)dlsym(vdso, name[4]);
+       vdso_init_from_sysinfo_ehdr(sysinfo_ehdr);
+
+       vdso_getcpu = (getcpu_t)vdso_sym(version, name[4]);
        if (!vdso_getcpu)
                printf("Warning: failed to find getcpu in vDSO\n");
 
        vgetcpu = (getcpu_t) vsyscall_getcpu();
 
-       vdso_clock_gettime = (vgettime_t)dlsym(vdso, name[1]);
+       vdso_clock_gettime = (vgettime_t)vdso_sym(version, name[1]);
        if (!vdso_clock_gettime)
                printf("Warning: failed to find clock_gettime in vDSO\n");
 
 #if defined(VDSO_32BIT)
-       vdso_clock_gettime64 = (vgettime64_t)dlsym(vdso, name[5]);
+       vdso_clock_gettime64 = (vgettime64_t)vdso_sym(version, name[5]);
        if (!vdso_clock_gettime64)
                printf("Warning: failed to find clock_gettime64 in vDSO\n");
 #endif
 
-       vdso_gettimeofday = (vgtod_t)dlsym(vdso, name[0]);
+       vdso_gettimeofday = (vgtod_t)vdso_sym(version, name[0]);
        if (!vdso_gettimeofday)
                printf("Warning: failed to find gettimeofday in vDSO\n");
 
@@ -429,6 +424,7 @@ static void test_gettimeofday(void)
 
 int main(int argc, char **argv)
 {
+       version = versions[VDSO_VERSION];
        name = (const char **)&names[VDSO_NAMES];
 
        fill_function_pointers();