Re: [PATCH v6 19/19] kselftest: Extend vDSO selftest

Arnd Bergmann
2019-05-31T08:53:57Z

On Thu, May 30, 2019 at 4:16 PM Vincenzo Frascino
<vincenzo.frascino@arm.com> wrote:

> +/*
> + * ARM64's vDSO exports its vDSO implementation with different names and
> + * a different 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[4] = {
> + "__kernel_gettimeofday",
> + "__kernel_clock_gettime",
> + "__kernel_time",
> + "__kernel_clock_getres",
> +};
> +#else
> +/* Tested on x86, arm, mips */
> +const char *version = "LINUX_2.6";
> +const char *name[4] = {
> + "__vdso_gettimeofday",
> + "__vdso_clock_gettime",
> + "__vdso_time",
> + "__vdso_clock_getres",
> +};
> +#endif

I see the __kernel_* name used on arm64, powerpc and s390, whiel the __vdso_*
name is used on arm, mips, nds32, riscv, sparc, and x86.

Also the versions have more variants:

$ git ls-files arch | grep vdso | xargs grep
'\(LINUX_[2345]\|VDSO_VERSION_STRING\)'
arch/arm/vdso/vdso.lds.S: LINUX_2.6 {
arch/arm64/kernel/vdso/vdso.lds.S: LINUX_2.6.39 {
arch/mips/vdso/vdso.lds.S: LINUX_2.6 {
arch/nds32/kernel/vdso/vdso.lds.S: LINUX_4 {
arch/powerpc/include/asm/vdso.h:#define VDSO_VERSION_STRING LINUX_2.6.15
arch/powerpc/kernel/vdso32/vdso32.lds.S: VDSO_VERSION_STRING {
arch/powerpc/kernel/vdso64/vdso64.lds.S: VDSO_VERSION_STRING {
arch/riscv/kernel/vdso/vdso.lds.S: LINUX_4.15 {
arch/s390/include/asm/vdso.h:#define VDSO_VERSION_STRING LINUX_2.6.29
arch/s390/kernel/vdso32/vdso32.lds.S: VDSO_VERSION_STRING {
arch/s390/kernel/vdso64/vdso64.lds.S: VDSO_VERSION_STRING {
arch/sparc/vdso/vdso.lds.S: LINUX_2.6 {
arch/sparc/vdso/vdso32/vdso32.lds.S: LINUX_2.6 {
arch/x86/entry/vdso/vdso.lds.S: LINUX_2.6 {
arch/x86/entry/vdso/vdso32/vdso32.lds.S: LINUX_2.6 {
arch/x86/entry/vdso/vdso32/vdso32.lds.S: LINUX_2.5 {
arch/x86/entry/vdso/vdsox32.lds.S: LINUX_2.6 {
arch/x86/um/vdso/vdso.lds.S: LINUX_2.6 {

Maybe change the test case to just try all combinations of the
above (and __vdso_clock_gettime64 as well) and stop checking
the architecture?

Arnd