| Message ID | 20211012234606.91717-2-ndesaulniers@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | compat vdso cleanups | expand |
On Wed, Oct 13, 2021 at 1:46 AM Nick Desaulniers <ndesaulniers@google.com> wrote: > > Binutils added support for this instruction in commit > e797f7e0b2bedc9328d4a9a0ebc63ca7a2dbbebc which shipped in 2.34 (just > missing the 2.33 release) but was cherry-picked into 2.33 in commit > 27a50d6755bae906bc73b4ec1a8b448467f0bea1. Thanks to Christian and Simon > for helping me with the patch archaeology. > > According to Documentation/process/changes.rst, the minimum supported > version of binutils is 2.33. Since all supported versions of GAS support > this instruction, drop the assembler invocation, preprocessor > flags/guards, and the cross assembler macro that's now unused. > > This also avoids a recursive self reference in a follow up cleanup > patch. > > Cc: Christian Biesinger <cbiesinger@google.com> > Cc: Simon Marchi <simon.marchi@polymtl.ca> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> This change looks good, but I think we should do the same for the gcc version check: > -#if __LINUX_ARM_ARCH__ >= 8 && defined(CONFIG_AS_DMB_ISHLD) > +#if __LINUX_ARM_ARCH__ >= 8 > #define aarch32_smp_mb() dmb(ish) > #define aarch32_smp_rmb() dmb(ishld) > #define aarch32_smp_wmb() dmb(ishst) gcc-4.8 already supported -march=armv8, and we require gcc-5.1 now, so both this #if/#else construct and the corresponding "cc32-option,-march=armv8-a" check should be obsolete now. Arnd
Hi Nick, On Tue, Oct 12, 2021 at 7:46 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > Binutils added support for this instruction in commit > e797f7e0b2bedc9328d4a9a0ebc63ca7a2dbbebc which shipped in 2.34 (just > missing the 2.33 release) but was cherry-picked into 2.33 in commit Shouldn't that be 2.24 and 2.23, respectively? > 27a50d6755bae906bc73b4ec1a8b448467f0bea1. Thanks to Christian and Simon > for helping me with the patch archaeology. > > According to Documentation/process/changes.rst, the minimum supported > version of binutils is 2.33. Since all supported versions of GAS support (I have not checked whether this version is correct or not.) Christian
diff --git a/arch/arm64/include/asm/vdso/compat_barrier.h b/arch/arm64/include/asm/vdso/compat_barrier.h index 3fd8fd6d8fc2..fb60a88b5ed4 100644 --- a/arch/arm64/include/asm/vdso/compat_barrier.h +++ b/arch/arm64/include/asm/vdso/compat_barrier.h @@ -20,7 +20,7 @@ #define dmb(option) __asm__ __volatile__ ("dmb " #option : : : "memory") -#if __LINUX_ARM_ARCH__ >= 8 && defined(CONFIG_AS_DMB_ISHLD) +#if __LINUX_ARM_ARCH__ >= 8 #define aarch32_smp_mb() dmb(ish) #define aarch32_smp_rmb() dmb(ishld) #define aarch32_smp_wmb() dmb(ishst) diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile index 3dba0c4f8f42..89299a26638b 100644 --- a/arch/arm64/kernel/vdso32/Makefile +++ b/arch/arm64/kernel/vdso32/Makefile @@ -29,8 +29,6 @@ cc32-option = $(call try-run,\ $(CC_COMPAT) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2)) cc32-disable-warning = $(call try-run,\ $(CC_COMPAT) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) -cc32-as-instr = $(call try-run,\ - printf "%b\n" "$(1)" | $(CC_COMPAT) $(VDSO_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) # We cannot use the global flags to compile the vDSO files, the main reason # being that the 32-bit compiler may be older than the main (64-bit) compiler @@ -113,12 +111,6 @@ endif VDSO_AFLAGS := $(VDSO_CAFLAGS) VDSO_AFLAGS += -D__ASSEMBLY__ -# Check for binutils support for dmb ishld -dmbinstr := $(call cc32-as-instr,dmb ishld,-DCONFIG_AS_DMB_ISHLD=1) - -VDSO_CFLAGS += $(dmbinstr) -VDSO_AFLAGS += $(dmbinstr) - # From arm vDSO Makefile VDSO_LDFLAGS += -Bsymbolic --no-undefined -soname=linux-vdso.so.1 VDSO_LDFLAGS += -z max-page-size=4096 -z common-page-size=4096
Binutils added support for this instruction in commit e797f7e0b2bedc9328d4a9a0ebc63ca7a2dbbebc which shipped in 2.34 (just missing the 2.33 release) but was cherry-picked into 2.33 in commit 27a50d6755bae906bc73b4ec1a8b448467f0bea1. Thanks to Christian and Simon for helping me with the patch archaeology. According to Documentation/process/changes.rst, the minimum supported version of binutils is 2.33. Since all supported versions of GAS support this instruction, drop the assembler invocation, preprocessor flags/guards, and the cross assembler macro that's now unused. This also avoids a recursive self reference in a follow up cleanup patch. Cc: Christian Biesinger <cbiesinger@google.com> Cc: Simon Marchi <simon.marchi@polymtl.ca> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> --- arch/arm64/include/asm/vdso/compat_barrier.h | 2 +- arch/arm64/kernel/vdso32/Makefile | 8 -------- 2 files changed, 1 insertion(+), 9 deletions(-)