Both vdso_test_gettimeofday and vdso_standalone_test_x86 use the library in parse_vdso.c but each separately declares the API it offers which is not ideal. Create a header file with prototypes of the functions and use it in both the library and the tests to ensure that the same prototypes are used throughout.

Signed-off-by: Mark Brown broonie@kernel.org --- tools/testing/selftests/vDSO/parse_vdso.c | 24 +------------- tools/testing/selftests/vDSO/parse_vdso.h | 31 +++++++++++++++++++ .../selftests/vDSO/vdso_standalone_test_x86.c | 4 +-- .../selftests/vDSO/vdso_test_gettimeofday.c | 5 +-- 4 files changed, 34 insertions(+), 30 deletions(-) create mode 100644 tools/testing/selftests/vDSO/parse_vdso.h

diff --git a/tools/testing/selftests/vDSO/parse_vdso.c b/tools/testing/selftests/vDSO/parse_vdso.c index 1dbb4b87268f..413f75620a35 100644 --- a/tools/testing/selftests/vDSO/parse_vdso.c +++ b/tools/testing/selftests/vDSO/parse_vdso.c @@ -21,29 +21,7 @@ #include <limits.h> #include <elf.h>

-/* - * To use this vDSO parser, first call one of the vdso_init_* functions. - * If you've already parsed auxv, then pass the value of AT_SYSINFO_EHDR - * to vdso_init_from_sysinfo_ehdr. Otherwise pass auxv to vdso_init_from_auxv. - * Then call vdso_sym for each symbol you want. For example, to look up - * gettimeofday on x86_64, use: - * - * <some pointer> = vdso_sym("LINUX_2.6", "gettimeofday"); - * or - * <some pointer> = vdso_sym("LINUX_2.6", "__vdso_gettimeofday"); - * - * vdso_sym will return 0 if the symbol doesn't exist or if the init function - * failed or was not called. vdso_sym is a little slow, so its return value - * should be cached. - * - * vdso_sym is threadsafe; the init functions are not. - * - * These are the prototypes: - */ -extern void vdso_init_from_auxv(void *auxv); -extern void vdso_init_from_sysinfo_ehdr(uintptr_t base); -extern void *vdso_sym(const char *version, const char *name); - +#include "parse_vdso.h"

/* And here's the code. */ #ifndef ELF_BITS diff --git a/tools/testing/selftests/vDSO/parse_vdso.h b/tools/testing/selftests/vDSO/parse_vdso.h new file mode 100644 index 000000000000..ea4b8635bb0b --- /dev/null +++ b/tools/testing/selftests/vDSO/parse_vdso.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef PARSE_VDSO_H +#define PARSE_VDSO_H + +#include <stdint.h> + +/* + * To use this vDSO parser, first call one of the vdso_init_* functions. + * If you've already parsed auxv, then pass the value of AT_SYSINFO_EHDR + * to vdso_init_from_sysinfo_ehdr. Otherwise pass auxv to vdso_init_from_auxv. + * Then call vdso_sym for each symbol you want. For example, to look up + * gettimeofday on x86_64, use: + * + * <some pointer> = vdso_sym("LINUX_2.6", "gettimeofday"); + * or + * <some pointer> = vdso_sym("LINUX_2.6", "__vdso_gettimeofday"); + * + * vdso_sym will return 0 if the symbol doesn't exist or if the init function + * failed or was not called. vdso_sym is a little slow, so its return value + * should be cached. + * + * vdso_sym is threadsafe; the init functions are not. + * + * These are the prototypes: + */ +extern void *vdso_sym(const char *version, const char *name); +extern void vdso_init_from_sysinfo_ehdr(uintptr_t base); +extern void vdso_init_from_auxv(void *auxv); + +#endif diff --git a/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c b/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c index 5ac4b00acfbc..8a44ff973ee1 100644 --- a/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c +++ b/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c @@ -16,9 +16,7 @@ #include <unistd.h> #include <stdint.h>

-extern void *vdso_sym(const char *version, const char *name); -extern void vdso_init_from_sysinfo_ehdr(uintptr_t base); -extern void vdso_init_from_auxv(void *auxv); +#include "parse_vdso.h"

/* We need a libc functions... */ int strcmp(const char *a, const char *b) diff --git a/tools/testing/selftests/vDSO/vdso_test_gettimeofday.c b/tools/testing/selftests/vDSO/vdso_test_gettimeofday.c index 511c0dc5e47e..8ccc73ed8240 100644 --- a/tools/testing/selftests/vDSO/vdso_test_gettimeofday.c +++ b/tools/testing/selftests/vDSO/vdso_test_gettimeofday.c @@ -17,10 +17,7 @@ #include <sys/time.h>

#include "../kselftest.h" - -extern void *vdso_sym(const char *version, const char *name); -extern void vdso_init_from_sysinfo_ehdr(uintptr_t base); -extern void vdso_init_from_auxv(void *auxv); +#include "parse_vdso.h"

/* * ARM64's vDSO exports its gettimeofday() implementation with a different

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

diff --git a/tools/testing/selftests/vDSO/.gitignore b/tools/testing/selftests/vDSO/.gitignore index 74f49bd5f6dd..5eb64d41e541 100644 --- a/tools/testing/selftests/vDSO/.gitignore +++ b/tools/testing/selftests/vDSO/.gitignore @@ -1,4 +1,5 @@ # SPDX-License-Identifier: GPL-2.0-only vdso_test vdso_test_gettimeofday +vdso_test_getcpu vdso_standalone_test_x86 diff --git a/tools/testing/selftests/vDSO/Makefile b/tools/testing/selftests/vDSO/Makefile index ae15d700b62e..0069f2f83f86 100644 --- a/tools/testing/selftests/vDSO/Makefile +++ b/tools/testing/selftests/vDSO/Makefile @@ -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 \ diff --git a/tools/testing/selftests/vDSO/vdso_test_getcpu.c b/tools/testing/selftests/vDSO/vdso_test_getcpu.c new file mode 100644 index 000000000000..fc25ede131b8 --- /dev/null +++ b/tools/testing/selftests/vDSO/vdso_test_getcpu.c @@ -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; +}