| Message ID | 20190926133805.52348-2-vincenzo.frascino@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: vdso32: Address various issues | expand |
On Thu, Sep 26, 2019 at 02:38:02PM +0100, Vincenzo Frascino wrote: > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 37c610963eee..13e2d2e16af7 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_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_GCC > + def_bool $(success,$(CROSS_COMPILE_COMPAT)gcc --version | head -n 1 | grep -q arm) Nitpick: COMPAT_CC_IS_ARM_GCC together with 'grep -q "arm-.*-gcc"' The patch below allows me to use $(COMPATCC) directly here and also set either CROSS_COMPILE_COMPAT or COMPATCC on the command line: ----------8<---------------------------------- diff --git a/arch/arm64/Kbuild b/arch/arm64/Kbuild index 75cf8c796d0e..d6465823b281 100644 --- a/arch/arm64/Kbuild +++ b/arch/arm64/Kbuild @@ -4,9 +4,3 @@ obj-$(CONFIG_NET) += net/ obj-$(CONFIG_KVM) += kvm/ obj-$(CONFIG_XEN) += xen/ obj-$(CONFIG_CRYPTO) += crypto/ - -# as-instr-compat -# Usage: cflags-y += $(call as-instr-compat,instr,option1,option2) - -as-instr-compat = $(call try-run,\ - printf "%b\n" "$(1)" | $(COMPATCC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 5d4be0b4f980..811c89fa2b71 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -110,7 +110,7 @@ config ARM64 select GENERIC_STRNLEN_USER select GENERIC_TIME_VSYSCALL select GENERIC_GETTIMEOFDAY - select GENERIC_COMPAT_VDSO if (!CPU_BIG_ENDIAN && COMPAT && COMPATCC_IS_GCC) + select GENERIC_COMPAT_VDSO if (!CPU_BIG_ENDIAN && COMPAT && COMPATCC_IS_ARM_GCC) select HANDLE_DOMAIN_IRQ select HARDIRQS_SW_RESEND select HAVE_PCI @@ -313,8 +313,8 @@ config KASAN_SHADOW_OFFSET default 0xeffffff900000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS default 0xffffffffffffffff -config COMPATCC_IS_GCC - def_bool $(success,$(CROSS_COMPILE_COMPAT)gcc --version | head -n 1 | grep -q arm) +config COMPATCC_IS_ARM_GCC + def_bool $(success,$(COMPATCC) --version | head -n 1 | grep -q "arm-.*-gcc") source "arch/arm64/Kconfig.platforms" diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 34f53eb11878..6b4eb5c444c5 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -53,6 +53,9 @@ $(warning Detected assembler with broken .inst; disassembly will be unreliable) endif endif +COMPATCC ?= $(CROSS_COMPILE_COMPAT)gcc +export COMPATCC + ifeq ($(CONFIG_GENERIC_COMPAT_VDSO), y) export CONFIG_COMPAT_VDSO := y compat_vdso := -DCONFIG_COMPAT_VDSO=1 diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile index 22f0d31ea528..77aa61340374 100644 --- a/arch/arm64/kernel/vdso32/Makefile +++ b/arch/arm64/kernel/vdso32/Makefile @@ -8,8 +8,6 @@ ARCH_REL_TYPE_ABS := R_ARM_JUMP_SLOT|R_ARM_GLOB_DAT|R_ARM_ABS32 include $(srctree)/lib/vdso/Makefile -COMPATCC := $(CROSS_COMPILE_COMPAT)gcc - # Same as cc-*option, but using COMPATCC instead of CC cc32-option = $(call try-run,\ $(COMPATCC) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 37c610963eee..13e2d2e16af7 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_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_GCC + def_bool $(success,$(CROSS_COMPILE_COMPAT)gcc --version | head -n 1 | grep -q arm) + source "arch/arm64/Kconfig.platforms" menu "Kernel Features" 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 KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr) $(brokengasinst) \
As reported by Will Deacon the .config file and the generated include/config/auto.conf can end up out of sync after a set of commands since CONFIG_CROSS_COMPILE_COMPAT_VDSO is not updated correctly. The sequence can be reproduced as follows: $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig [...] $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- menuconfig [set CONFIG_CROSS_COMPILE_COMPAT_VDSO="arm-linux-gnueabihf-"] $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- Which results in: arch/arm64/Makefile:62: CROSS_COMPILE_COMPAT not defined or empty, the compat vDSO will not be built even though the compat vDSO has been built: $ file arch/arm64/kernel/vdso32/vdso.so arch/arm64/kernel/vdso32/vdso.so: ELF 32-bit LSB pie executable, ARM, EABI5 version 1 (SYSV), dynamically linked, BuildID[sha1]=c67f6c786f2d2d6f86c71f708595594aa25247f6, stripped A similar case that involves changing the configuration parameter multiple times can be reconducted to the same family of problems. The reason behind it comes from the fact that the master Makefile includes that architecture Makefile twice, once before the syncconfig and one after. Since the synchronization of the files happens only upon syncconfig, the architecture Makefile included before this event does not see the change in configuration. As a consequence of this it is not possible to handle the cross compiler definitions inside the architecture Makefile. Address the problem removing CONFIG_CROSS_COMPILE_COMPAT_VDSO and moving the detection of the correct compiler into Kconfig via COMPAT_CC_IS_GCC. As a consequence of this it is not possible anymore to set the compat cross compiler from menuconfig but it requires to be exported via command line. E.g.: $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- CROSS_COMPILE_COMPAT=arm-linux-gnueabihf Cc: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> --- arch/arm64/Kconfig | 5 ++++- arch/arm64/Makefile | 15 ++------------- 2 files changed, 6 insertions(+), 14 deletions(-)