On Tue, Oct 01, 2019 at 03:20:35PM +0100, Vincenzo Frascino wrote: > On 10/1/19 2:27 PM, Catalin Marinas wrote: > > On Tue, Oct 01, 2019 at 02:14:23PM +0100, Will Deacon wrote: > >> On Thu, Sep 26, 2019 at 10:43:38PM +0100, Vincenzo Frascino wrote: > >>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > >>> index 37c610963eee..0e5beb928af5 100644 > >>> --- a/arch/arm64/Kconfig > >>> +++ b/arch/arm64/Kconfig > >>> @@ -110,7 +110,7 @@ config ARM64 > >>> select GENERIC_STRNLEN_USER > >>> select GENERIC_TIME_VSYSCALL > >>> select GENERIC_GETTIMEOFDAY > >>> - select GENERIC_COMPAT_VDSO if (!CPU_BIG_ENDIAN && COMPAT) > >>> + select GENERIC_COMPAT_VDSO if (!CPU_BIG_ENDIAN && COMPAT && > >>> COMPATCC_IS_ARM_GCC) > >>> select HANDLE_DOMAIN_IRQ > >>> select HARDIRQS_SW_RESEND > >>> select HAVE_PCI > >>> @@ -313,6 +313,9 @@ config KASAN_SHADOW_OFFSET > >>> default 0xeffffff900000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS > >>> default 0xffffffffffffffff > >>> > >>> +config COMPATCC_IS_ARM_GCC > >>> + def_bool $(success,$(COMPATCC) --version | head -n 1 | grep -q > >>> "arm-.*-gcc") > >> > >> I've seen toolchains where the first part of the tuple is "armv7-", so they > >> won't get detected here. However, do we really need to detect this? If > >> somebody passes a duff compiler, then the build will fail in the same way > >> as > >> if they passed it to CROSS_COMPILE=. > > > > Not sure what happens if we pass an aarch64 compiler. Can we end up with > > a 64-bit compat vDSO? > > > > I agree with Catalin here. The problem is not only when you pass and aarch64 > toolchain but even an x86 and so on.
I disagree. What happens if you do: $ make ARCH=arm64 CROSS_COMPILE=x86_64-linux-gnu- on your x86 box? > If the problem is related to armv7- we can change the rule as "arm.*-gcc" > which > should detect them as well. Do you know what is the triple that an armv7- > toolchain prints? 'fraid not, since I don't have one to hand. I think you'd end up matching arm*-gcc, which is pretty broad. Will
