Messages in this thread | | | Subject | Re: [PATCH 1/4] arm64: vdso32: Introduce COMPAT_CC_IS_GCC | From | Vincenzo Frascino <> | Date | Thu, 26 Sep 2019 13:22:01 +0100 |
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On 9/26/19 11:56 AM, Vincenzo Frascino wrote: > On 9/26/19 9:06 AM, Catalin Marinas wrote: >> On Thu, Sep 26, 2019 at 07:03:50AM +0100, Vincenzo Frascino wrote: >>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >>> index 37c610963eee..afe8c948b493 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 && COMPAT_CC_IS_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 COMPAT_CC_IS_GCC >>> + def_bool $(success,$(CROSS_COMPILE_COMPAT)gcc --version | head -n 1 | grep -q arm) >> >> Nitpick: I prefer COMPATCC instead of COMPAT_CC for consistency with >> HOSTCC. >> > > Ok, will change this in v2. > >> Now, could we not generate a COMPATCC in the Makefile and use >> $(COMPATCC) here instead of $(CROSS_COMPILE_COMPAT)gcc? It really >> doesn't make sense to check that gcc is gcc. >> > > All right, COMPATCC is already in the makefile, I will use it in here. >
What you are proposing seems not possible because Kconfig runs first and then the arch Makefile, hence compatcc does not take effect on the Kconfig. I will post v2 with what I proposed, please feel free to comment if you have a better idea.
arch/arm64/configs/defconfig:726:warning: symbol value 'm' invalid for REMOTEPROC #
# configuration written to .config
#
make[1]: Leaving directory '/data1/Projects/LinuxKernel/linux-out'
make[1]: Entering directory '/data1/Projects/LinuxKernel/linux-out'
$COMPATCC is [arm-linux-gnueabihf-gcc]
GEN Makefile
>> A next step would be to check that COMPATCC can actually generate 32-bit >> objects. But it's not essential at this stage. >> > > We are already checking this making sure that arm is present in the triple (grep > -q arm). > >>> diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile >>> index 84a3d502c5a5..34f53eb11878 100644 >>> --- a/arch/arm64/Makefile >>> +++ b/arch/arm64/Makefile >>> @@ -54,19 +54,8 @@ $(warning Detected assembler with broken .inst; disassembly will be unreliable) >>> endif >>> >>> ifeq ($(CONFIG_GENERIC_COMPAT_VDSO), y) >>> - CROSS_COMPILE_COMPAT ?= $(CONFIG_CROSS_COMPILE_COMPAT_VDSO:"%"=%) >>> - >>> - ifeq ($(CONFIG_CC_IS_CLANG), y) >>> - $(warning CROSS_COMPILE_COMPAT is clang, the compat vDSO will not be built) >>> - else ifeq ($(strip $(CROSS_COMPILE_COMPAT)),) >>> - $(warning CROSS_COMPILE_COMPAT not defined or empty, the compat vDSO will not be built) >>> - else ifeq ($(shell which $(CROSS_COMPILE_COMPAT)gcc 2> /dev/null),) >>> - $(error $(CROSS_COMPILE_COMPAT)gcc not found, check CROSS_COMPILE_COMPAT) >>> - else >>> - export CROSS_COMPILE_COMPAT >>> - export CONFIG_COMPAT_VDSO := y >>> - compat_vdso := -DCONFIG_COMPAT_VDSO=1 >>> - endif >>> + export CONFIG_COMPAT_VDSO := y >>> + compat_vdso := -DCONFIG_COMPAT_VDSO=1 >>> endif >> >> Has CONFIG_CROSS_COMPILE_COMPAT_VDSO actually been removed from >> lib/vdso/Kconfig? (I haven't checked the subsequent patches). >> >
-- Regards, Vincenzo
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