Re: [PATCH v2] arm64: vdso32: add CONFIG_THUMB2_COMPAT_VDSO

Catalin Marinas
2020-06-09T20:35:15Z

On Mon, Jun 08, 2020 at 01:57:08PM -0700, Nick Desaulniers wrote:
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 7f9d38444d6d..fe9e6b231cac 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -1299,6 +1299,14 @@ config COMPAT_VDSO
> You must have a 32-bit build of glibc 2.22 or later for programs
> to seamlessly take advantage of this.
>
> +config THUMB2_COMPAT_VDSO
> + bool "Compile the vDSO in THUMB2 mode"
> + depends on COMPAT_VDSO
> + default y
> + help
> + Compile the compat vDSO with -mthumb -fomit-frame-pointer if y, otherwise
> + as -marm.

Now that we understood the issue (I think), do we actually need this
choice? Why not going for -mthumb -fomit-frame-pointer always for the
compat vdso?

--
Catalin