@@ -1,4 +1,5 @@
# SPDX-License-Identifier: GPL-2.0-only
vdso_test
vdso_test_gettimeofday
+vdso_test_getcpu
vdso_standalone_test_x86
@@ -4,7 +4,7 @@ include ../lib.mk
uname_M := $(shell uname -m 2>/dev/null || echo not)
ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/x86/ -e s/x86_64/x86/)
-TEST_GEN_PROGS := $(OUTPUT)/vdso_test_gettimeofday
+TEST_GEN_PROGS := $(OUTPUT)/vdso_test_gettimeofday $(OUTPUT)/vdso_test_getcpu
ifeq ($(ARCH),x86)
TEST_GEN_PROGS += $(OUTPUT)/vdso_standalone_test_x86
endif
@@ -18,6 +18,7 @@ endif
all: $(TEST_GEN_PROGS)
$(OUTPUT)/vdso_test_gettimeofday: parse_vdso.c vdso_test_gettimeofday.c
+$(OUTPUT)/vdso_test_getcpu: parse_vdso.c vdso_test_getcpu.c
$(OUTPUT)/vdso_standalone_test_x86: vdso_standalone_test_x86.c parse_vdso.c
$(CC) $(CFLAGS) $(CFLAGS_vdso_standalone_test_x86) \
vdso_standalone_test_x86.c parse_vdso.c \
new file mode 100644
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * vdso_test_getcpu.c: Sample code to test parse_vdso.c and vDSO getcpu()
+ *
+ * Copyright (c) 2020 Arm Ltd
+ */
+
+#include <stdint.h>
+#include <elf.h>
+#include <stdio.h>
+#include <sys/auxv.h>
+#include <sys/time.h>
+
+#include "../kselftest.h"
+#include "parse_vdso.h"
+
+const char *version = "LINUX_2.6";
+const char *name = "__vdso_getcpu";
+
+struct getcpu_cache;
+typedef long (*getcpu_t)(unsigned int *, unsigned int *,
+ struct getcpu_cache *);
+
+int main(int argc, char **argv)
+{
+ unsigned long sysinfo_ehdr;
+ unsigned int cpu, node;
+ getcpu_t get_cpu;
+ long ret;
+
+ sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR);
+ if (!sysinfo_ehdr) {
+ printf("AT_SYSINFO_EHDR is not present!\n");
+ return KSFT_SKIP;
+ }
+
+ vdso_init_from_sysinfo_ehdr(getauxval(AT_SYSINFO_EHDR));
+
+ get_cpu = (getcpu_t)vdso_sym(version, name);
+ if (!get_cpu) {
+ printf("Could not find %s\n", name);
+ 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);
+ return KSFT_FAIL;
+ }
+
+ return 0;
+}
Provide a very basic selftest for getcpu() which similarly to our existing test for gettimeofday() looks up the function in the vDSO and prints the results it gets if the function exists and succeeds. Signed-off-by: Mark Brown <broonie@kernel.org> --- tools/testing/selftests/vDSO/.gitignore | 1 + tools/testing/selftests/vDSO/Makefile | 3 +- .../testing/selftests/vDSO/vdso_test_getcpu.c | 54 +++++++++++++++++++ 3 files changed, 57 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/vDSO/vdso_test_getcpu.c