| Message ID | 20210609102301.17332-3-mark.rutland@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: insn: cleanups | expand |
Hi Mark, On Wed, Jun 09, 2021 at 11:23:01AM +0100, Mark Rutland wrote: > For histroical reasons, we define AARCH64_INSN_SIZE in > <asm/alternative-macros.h>, but it would make more sense to do so in > <asm/insn.h>. Let's move it into <asm/insn.h>, and add the necessary > include directives for this. > > Signed-off-by: Mark Rutland <mark.rutland@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will@kernel.org> > --- > arch/arm64/include/asm/alternative-macros.h | 4 +--- > arch/arm64/include/asm/insn.h | 3 +++ > arch/arm64/include/asm/kvm_asm.h | 1 + > arch/arm64/kernel/cpufeature.c | 1 + > arch/arm64/kernel/patching.c | 1 + > arch/arm64/kernel/traps.c | 1 + > arch/arm64/net/bpf_jit_comp.c | 1 + > 7 files changed, 9 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/include/asm/alternative-macros.h b/arch/arm64/include/asm/alternative-macros.h > index 8a078fc662ac..703fbf310b79 100644 > --- a/arch/arm64/include/asm/alternative-macros.h > +++ b/arch/arm64/include/asm/alternative-macros.h > @@ -3,12 +3,10 @@ > #define __ASM_ALTERNATIVE_MACROS_H > > #include <asm/cpucaps.h> > +#include <asm/insn.h> > > #define ARM64_CB_PATCH ARM64_NCAPS > > -/* A64 instructions are always 32 bits. */ > -#define AARCH64_INSN_SIZE 4 > - > #ifndef __ASSEMBLY__ > > #include <linux/stringify.h> > diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h > index a6f3f45fc46f..1430b4973039 100644 > --- a/arch/arm64/include/asm/insn.h > +++ b/arch/arm64/include/asm/insn.h > @@ -12,6 +12,9 @@ > > #include <asm/alternative.h> > > +/* A64 instructions are always 32 bits. */ > +#define AARCH64_INSN_SIZE 4 > + > #ifndef __ASSEMBLY__ > /* > * ARM Architecture Reference Manual for ARMv8 Profile-A, Issue A.a > diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h > index cf8df032b9c3..894edda8cc85 100644 > --- a/arch/arm64/include/asm/kvm_asm.h > +++ b/arch/arm64/include/asm/kvm_asm.h > @@ -8,6 +8,7 @@ > #define __ARM_KVM_ASM_H__ > > #include <asm/hyp_image.h> > +#include <asm/insn.h> > #include <asm/virt.h> > > #define ARM_EXIT_WITH_SERROR_BIT 31 > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index efed2830d141..16d35cfffcea 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -76,6 +76,7 @@ > #include <asm/cpufeature.h> > #include <asm/cpu_ops.h> > #include <asm/fpsimd.h> > +#include <asm/insn.h> > #include <asm/kvm_host.h> > #include <asm/mmu_context.h> > #include <asm/mte.h> > diff --git a/arch/arm64/kernel/patching.c b/arch/arm64/kernel/patching.c > index 7aa55b33c8c7..9a6edb9c48c7 100644 > --- a/arch/arm64/kernel/patching.c > +++ b/arch/arm64/kernel/patching.c > @@ -8,6 +8,7 @@ > > #include <asm/cacheflush.h> > #include <asm/fixmap.h> > +#include <asm/insn.h> > #include <asm/kprobes.h> > #include <asm/patching.h> > #include <asm/sections.h> > diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c > index 48ff6fb888e0..8f66072fa5cb 100644 > --- a/arch/arm64/kernel/traps.c > +++ b/arch/arm64/kernel/traps.c > @@ -36,6 +36,7 @@ > #include <asm/esr.h> > #include <asm/exception.h> > #include <asm/extable.h> > +#include <asm/insn.h> > #include <asm/kprobes.h> > #include <asm/patching.h> > #include <asm/traps.h> > diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c > index f7b194878a99..dd5000da18b8 100644 > --- a/arch/arm64/net/bpf_jit_comp.c > +++ b/arch/arm64/net/bpf_jit_comp.c > @@ -16,6 +16,7 @@ > #include <asm/byteorder.h> > #include <asm/cacheflush.h> > #include <asm/debug-monitors.h> > +#include <asm/insn.h> > #include <asm/set_memory.h> > > #include "bpf_jit.h" > -- > 2.11.0 > I bisected a CONFIG_LTO_CLANG_THIN=y build failure that our CI reported to this patch: https://builds.tuxbuild.com/1u4Fpx2FQkkgkyPxWtq0Ke4YFCQ/build.log I have not had a whole ton of time to look into this (dealing with a million fires it seems :^) but it is not immediately obvious to me why this fails because include/linux/build_bug.h is included within arch/arm64/include/asm/insn.h. It seems only CONFIG_LTO_CLANG_THIN=y (or FULL) is enough to trigger this, a regular defconfig build is fine: https://builds.tuxbuild.com/1u4Fpt5M8quEVUd4kNSMrdzobC2/build.log I will try to look into this tomorrow but I figured I would let you know in case something obviously stuck out. Cheers, Nathan
On Thu, Jun 17, 2021 at 06:25:27PM -0700, Nathan Chancellor wrote: > Hi Mark, Hi Nathan, > On Wed, Jun 09, 2021 at 11:23:01AM +0100, Mark Rutland wrote: > > For histroical reasons, we define AARCH64_INSN_SIZE in > > <asm/alternative-macros.h>, but it would make more sense to do so in > > <asm/insn.h>. Let's move it into <asm/insn.h>, and add the necessary > > include directives for this. > I bisected a CONFIG_LTO_CLANG_THIN=y build failure that our CI reported > to this patch: > > https://builds.tuxbuild.com/1u4Fpx2FQkkgkyPxWtq0Ke4YFCQ/build.log Thanks for reporting this; the lopg is really helpful! > I have not had a whole ton of time to look into this (dealing with a > million fires it seems :^) but it is not immediately obvious to me why > this fails because include/linux/build_bug.h is included within > arch/arm64/include/asm/insn.h. The problem is that with LTO, we patch READ_ONCE(), and <asm/rwonce.h> includes <asm/insn.h>, creating a circular include chain: <linux/build_bug.h> <linux/compiler.h> <asm/rwonce.h> <asm/alternative-macros.h> <asm/insn.h> <linux/build-bug.h> ... and so when <asm/insn.h> includes <linux/build_bug.h>, none of the BUILD_BUG* definitions have happened yet. Will, are you happy to take the fixup patch below, or would you prefer to drop this patch for now? Thanks, Mark. ---->8---- From 0acc3d92302f54475d938f55749805adf74faec1 Mon Sep 17 00:00:00 2001 From: Mark Rutland <mark.rutland@arm.com> Date: Fri, 18 Jun 2021 16:11:22 +0100 Subject: [PATCH] arm64: insn: avoid circular include dependency Nathan reports that when building with CONFIG_LTO_CLANG_THIN=y, the build fails due to BUILD_BUG_ON() not being defined before its uss in <asm/insn.h>. The problem is that with LTO, we patch READ_ONCE(), and <asm/rwonce.h> includes <asm/insn.h>, creating a circular include chain: <linux/build_bug.h> <linux/compiler.h> <asm/rwonce.h> <asm/alternative-macros.h> <asm/insn.h> <linux/build-bug.h> ... and so when <asm/insn.h> includes <linux/build_bug.h>, none of the BUILD_BUG* definitions have happened yet. To avoid this, let's move AARCH64_INSN_SIZE into a header without any dependencies, such that it can always be safely included. At the same time, avoid including <asm/alternative.h> in <asm/insn.h>, which should no longer be necessary (and doesn't make sense when insn.h is consumed by userspace). Reported-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> --- arch/arm64/include/asm/alternative-macros.h | 2 +- arch/arm64/include/asm/insn.h | 5 +---- 2 files changed, 2 insertions(+), 5 deletions(-) diff --git a/arch/arm64/include/asm/alternative-macros.h b/arch/arm64/include/asm/alternative-macros.h index 703fbf310b79..eba3173a2a2c 100644 --- a/arch/arm64/include/asm/alternative-macros.h +++ b/arch/arm64/include/asm/alternative-macros.h @@ -3,7 +3,7 @@ #define __ASM_ALTERNATIVE_MACROS_H #include <asm/cpucaps.h> -#include <asm/insn.h> +#include <asm/insn-def.h> #define ARM64_CB_PATCH ARM64_NCAPS diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h index 1430b4973039..6b776c8667b2 100644 --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -10,10 +10,7 @@ #include <linux/build_bug.h> #include <linux/types.h> -#include <asm/alternative.h> - -/* A64 instructions are always 32 bits. */ -#define AARCH64_INSN_SIZE 4 +#include <asm/insn-def.h> #ifndef __ASSEMBLY__ /*
On Fri, Jun 18, 2021 at 04:18:35PM +0100, Mark Rutland wrote: > On Thu, Jun 17, 2021 at 06:25:27PM -0700, Nathan Chancellor wrote: > > Hi Mark, > > Hi Nathan, > > > On Wed, Jun 09, 2021 at 11:23:01AM +0100, Mark Rutland wrote: > > > For histroical reasons, we define AARCH64_INSN_SIZE in > > > <asm/alternative-macros.h>, but it would make more sense to do so in > > > <asm/insn.h>. Let's move it into <asm/insn.h>, and add the necessary > > > include directives for this. > > > I bisected a CONFIG_LTO_CLANG_THIN=y build failure that our CI reported > > to this patch: > > > > https://builds.tuxbuild.com/1u4Fpx2FQkkgkyPxWtq0Ke4YFCQ/build.log > > Thanks for reporting this; the lopg is really helpful! > > > I have not had a whole ton of time to look into this (dealing with a > > million fires it seems :^) but it is not immediately obvious to me why > > this fails because include/linux/build_bug.h is included within > > arch/arm64/include/asm/insn.h. > > The problem is that with LTO, we patch READ_ONCE(), and <asm/rwonce.h> > includes <asm/insn.h>, creating a circular include chain: > > <linux/build_bug.h> > <linux/compiler.h> > <asm/rwonce.h> > <asm/alternative-macros.h> > <asm/insn.h> > <linux/build-bug.h> > > ... and so when <asm/insn.h> includes <linux/build_bug.h>, none of the > BUILD_BUG* definitions have happened yet. Aha, that would certainly explain it. I figured something like this would be the root cause but figuring out header dependencies is not my cup of tea. > Will, are you happy to take the fixup patch below, or would you prefer > to drop this patch for now? > > Thanks, > Mark. > > ---->8---- > >From 0acc3d92302f54475d938f55749805adf74faec1 Mon Sep 17 00:00:00 2001 > From: Mark Rutland <mark.rutland@arm.com> > Date: Fri, 18 Jun 2021 16:11:22 +0100 > Subject: [PATCH] arm64: insn: avoid circular include dependency > > Nathan reports that when building with CONFIG_LTO_CLANG_THIN=y, the > build fails due to BUILD_BUG_ON() not being defined before its uss in > <asm/insn.h>. > > The problem is that with LTO, we patch READ_ONCE(), and <asm/rwonce.h> > includes <asm/insn.h>, creating a circular include chain: > > <linux/build_bug.h> > <linux/compiler.h> > <asm/rwonce.h> > <asm/alternative-macros.h> > <asm/insn.h> > <linux/build-bug.h> > > ... and so when <asm/insn.h> includes <linux/build_bug.h>, none of the > BUILD_BUG* definitions have happened yet. > > To avoid this, let's move AARCH64_INSN_SIZE into a header without any > dependencies, such that it can always be safely included. At the same > time, avoid including <asm/alternative.h> in <asm/insn.h>, which should > no longer be necessary (and doesn't make sense when insn.h is consumed > by userspace). > > Reported-by: Nathan Chancellor <nathan@kernel.org> > Signed-off-by: Mark Rutland <mark.rutland@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will@kernel.org> > --- > arch/arm64/include/asm/alternative-macros.h | 2 +- > arch/arm64/include/asm/insn.h | 5 +---- Looks like arch/arm64/include/asm/insn-def.h is missing from this patch? If I add one with just the two deleted lines plus a header guard, the build passes. Tested-by: Nathan Chancellor <nathan@kernel.org> Thank you for the quick fix! Cheers, Nathan > 2 files changed, 2 insertions(+), 5 deletions(-) > > diff --git a/arch/arm64/include/asm/alternative-macros.h b/arch/arm64/include/asm/alternative-macros.h > index 703fbf310b79..eba3173a2a2c 100644 > --- a/arch/arm64/include/asm/alternative-macros.h > +++ b/arch/arm64/include/asm/alternative-macros.h > @@ -3,7 +3,7 @@ > #define __ASM_ALTERNATIVE_MACROS_H > > #include <asm/cpucaps.h> > -#include <asm/insn.h> > +#include <asm/insn-def.h> > > #define ARM64_CB_PATCH ARM64_NCAPS > > diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h > index 1430b4973039..6b776c8667b2 100644 > --- a/arch/arm64/include/asm/insn.h > +++ b/arch/arm64/include/asm/insn.h > @@ -10,10 +10,7 @@ > #include <linux/build_bug.h> > #include <linux/types.h> > > -#include <asm/alternative.h> > - > -/* A64 instructions are always 32 bits. */ > -#define AARCH64_INSN_SIZE 4 > +#include <asm/insn-def.h> > > #ifndef __ASSEMBLY__ > /* > -- > 2.11.0 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Fri, Jun 18, 2021 at 09:53:31AM -0700, Nathan Chancellor wrote: > On Fri, Jun 18, 2021 at 04:18:35PM +0100, Mark Rutland wrote: > > On Thu, Jun 17, 2021 at 06:25:27PM -0700, Nathan Chancellor wrote: > > > Hi Mark, > > > > Hi Nathan, > > > > > On Wed, Jun 09, 2021 at 11:23:01AM +0100, Mark Rutland wrote: > > > > For histroical reasons, we define AARCH64_INSN_SIZE in > > > > <asm/alternative-macros.h>, but it would make more sense to do so in > > > > <asm/insn.h>. Let's move it into <asm/insn.h>, and add the necessary > > > > include directives for this. > > > > > I bisected a CONFIG_LTO_CLANG_THIN=y build failure that our CI reported > > > to this patch: > > > > > > https://builds.tuxbuild.com/1u4Fpx2FQkkgkyPxWtq0Ke4YFCQ/build.log > > > > Thanks for reporting this; the lopg is really helpful! > > > > > I have not had a whole ton of time to look into this (dealing with a > > > million fires it seems :^) but it is not immediately obvious to me why > > > this fails because include/linux/build_bug.h is included within > > > arch/arm64/include/asm/insn.h. > > > > The problem is that with LTO, we patch READ_ONCE(), and <asm/rwonce.h> > > includes <asm/insn.h>, creating a circular include chain: > > > > <linux/build_bug.h> > > <linux/compiler.h> > > <asm/rwonce.h> > > <asm/alternative-macros.h> > > <asm/insn.h> > > <linux/build-bug.h> > > > > ... and so when <asm/insn.h> includes <linux/build_bug.h>, none of the > > BUILD_BUG* definitions have happened yet. > > Aha, that would certainly explain it. I figured something like this > would be the root cause but figuring out header dependencies is not my > cup of tea. > > > Will, are you happy to take the fixup patch below, or would you prefer > > to drop this patch for now? > > arch/arm64/include/asm/alternative-macros.h | 2 +- > > arch/arm64/include/asm/insn.h | 5 +---- > > Looks like arch/arm64/include/asm/insn-def.h is missing from this patch? > > If I add one with just the two deleted lines plus a header guard, the > build passes. > > Tested-by: Nathan Chancellor <nathan@kernel.org> Whoops; that should have been as below. Was that the same as you tested? Thanks, Mark. ---->8---- From 622fd784c57423b1a276fbbfb270b84839e3afa8 Mon Sep 17 00:00:00 2001 From: Mark Rutland <mark.rutland@arm.com> Date: Fri, 18 Jun 2021 16:11:22 +0100 Subject: [PATCH] arm64: insn: avoid circular include dependency Nathan reports that when building with CONFIG_LTO_CLANG_THIN=y, the build fails due to BUILD_BUG_ON() not being defined before its uss in <asm/insn.h>. The problem is that with LTO, we patch READ_ONCE(), and <asm/rwonce.h> includes <asm/insn.h>, creating a circular include chain: <linux/build_bug.h> <linux/compiler.h> <asm/rwonce.h> <asm/alternative-macros.h> <asm/insn.h> <linux/build-bug.h> ... and so when <asm/insn.h> includes <linux/build_bug.h>, none of the BUILD_BUG* definitions have happened yet. To avoid this, let's move AARCH64_INSN_SIZE into a header without any dependencies, such that it can always be safely included. At the same time, avoid including <asm/alternative.h> in <asm/insn.h>, which should no longer be necessary (and doesn't make sense when insn.h is consumed by userspace). Reported-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> --- arch/arm64/include/asm/alternative-macros.h | 2 +- arch/arm64/include/asm/insn-def.h | 9 +++++++++ arch/arm64/include/asm/insn.h | 5 +---- 3 files changed, 11 insertions(+), 5 deletions(-) create mode 100644 arch/arm64/include/asm/insn-def.h diff --git a/arch/arm64/include/asm/alternative-macros.h b/arch/arm64/include/asm/alternative-macros.h index 703fbf310b79..eba3173a2a2c 100644 --- a/arch/arm64/include/asm/alternative-macros.h +++ b/arch/arm64/include/asm/alternative-macros.h @@ -3,7 +3,7 @@ #define __ASM_ALTERNATIVE_MACROS_H #include <asm/cpucaps.h> -#include <asm/insn.h> +#include <asm/insn-def.h> #define ARM64_CB_PATCH ARM64_NCAPS diff --git a/arch/arm64/include/asm/insn-def.h b/arch/arm64/include/asm/insn-def.h new file mode 100644 index 000000000000..2c075f615c6a --- /dev/null +++ b/arch/arm64/include/asm/insn-def.h @@ -0,0 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef __ASM_INSN_DEF_H +#define __ASM_INSN_DEF_H + +/* A64 instructions are always 32 bits. */ +#define AARCH64_INSN_SIZE 4 + +#endif /* __ASM_INSN_DEF_H */ diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h index 1430b4973039..6b776c8667b2 100644 --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -10,10 +10,7 @@ #include <linux/build_bug.h> #include <linux/types.h> -#include <asm/alternative.h> - -/* A64 instructions are always 32 bits. */ -#define AARCH64_INSN_SIZE 4 +#include <asm/insn-def.h> #ifndef __ASSEMBLY__ /*
On Mon, Jun 21, 2021 at 09:08:30AM +0100, Mark Rutland wrote: > On Fri, Jun 18, 2021 at 09:53:31AM -0700, Nathan Chancellor wrote: > > On Fri, Jun 18, 2021 at 04:18:35PM +0100, Mark Rutland wrote: > > > On Thu, Jun 17, 2021 at 06:25:27PM -0700, Nathan Chancellor wrote: > > > > Hi Mark, > > > > > > Hi Nathan, > > > > > > > On Wed, Jun 09, 2021 at 11:23:01AM +0100, Mark Rutland wrote: > > > > > For histroical reasons, we define AARCH64_INSN_SIZE in > > > > > <asm/alternative-macros.h>, but it would make more sense to do so in > > > > > <asm/insn.h>. Let's move it into <asm/insn.h>, and add the necessary > > > > > include directives for this. > > > > > > > I bisected a CONFIG_LTO_CLANG_THIN=y build failure that our CI reported > > > > to this patch: > > > > > > > > https://builds.tuxbuild.com/1u4Fpx2FQkkgkyPxWtq0Ke4YFCQ/build.log > > > > > > Thanks for reporting this; the lopg is really helpful! > > > > > > > I have not had a whole ton of time to look into this (dealing with a > > > > million fires it seems :^) but it is not immediately obvious to me why > > > > this fails because include/linux/build_bug.h is included within > > > > arch/arm64/include/asm/insn.h. > > > > > > The problem is that with LTO, we patch READ_ONCE(), and <asm/rwonce.h> > > > includes <asm/insn.h>, creating a circular include chain: > > > > > > <linux/build_bug.h> > > > <linux/compiler.h> > > > <asm/rwonce.h> > > > <asm/alternative-macros.h> > > > <asm/insn.h> > > > <linux/build-bug.h> > > > > > > ... and so when <asm/insn.h> includes <linux/build_bug.h>, none of the > > > BUILD_BUG* definitions have happened yet. > > > > Aha, that would certainly explain it. I figured something like this > > would be the root cause but figuring out header dependencies is not my > > cup of tea. > > > > > Will, are you happy to take the fixup patch below, or would you prefer > > > to drop this patch for now? > > > > arch/arm64/include/asm/alternative-macros.h | 2 +- > > > arch/arm64/include/asm/insn.h | 5 +---- > > > > Looks like arch/arm64/include/asm/insn-def.h is missing from this patch? > > > > If I add one with just the two deleted lines plus a header guard, the > > build passes. > > > > Tested-by: Nathan Chancellor <nathan@kernel.org> > > Whoops; that should have been as below. I've queued this locally on top of for-next/insn and will push out later on (once my LTO build has finished). Will
On 6/21/2021 1:08 AM, Mark Rutland wrote: > On Fri, Jun 18, 2021 at 09:53:31AM -0700, Nathan Chancellor wrote: >> On Fri, Jun 18, 2021 at 04:18:35PM +0100, Mark Rutland wrote: >>> On Thu, Jun 17, 2021 at 06:25:27PM -0700, Nathan Chancellor wrote: >>>> Hi Mark, >>> >>> Hi Nathan, >>> >>>> On Wed, Jun 09, 2021 at 11:23:01AM +0100, Mark Rutland wrote: >>>>> For histroical reasons, we define AARCH64_INSN_SIZE in >>>>> <asm/alternative-macros.h>, but it would make more sense to do so in >>>>> <asm/insn.h>. Let's move it into <asm/insn.h>, and add the necessary >>>>> include directives for this. >>> >>>> I bisected a CONFIG_LTO_CLANG_THIN=y build failure that our CI reported >>>> to this patch: >>>> >>>> https://builds.tuxbuild.com/1u4Fpx2FQkkgkyPxWtq0Ke4YFCQ/build.log >>> >>> Thanks for reporting this; the lopg is really helpful! >>> >>>> I have not had a whole ton of time to look into this (dealing with a >>>> million fires it seems :^) but it is not immediately obvious to me why >>>> this fails because include/linux/build_bug.h is included within >>>> arch/arm64/include/asm/insn.h. >>> >>> The problem is that with LTO, we patch READ_ONCE(), and <asm/rwonce.h> >>> includes <asm/insn.h>, creating a circular include chain: >>> >>> <linux/build_bug.h> >>> <linux/compiler.h> >>> <asm/rwonce.h> >>> <asm/alternative-macros.h> >>> <asm/insn.h> >>> <linux/build-bug.h> >>> >>> ... and so when <asm/insn.h> includes <linux/build_bug.h>, none of the >>> BUILD_BUG* definitions have happened yet. >> >> Aha, that would certainly explain it. I figured something like this >> would be the root cause but figuring out header dependencies is not my >> cup of tea. >> >>> Will, are you happy to take the fixup patch below, or would you prefer >>> to drop this patch for now? > >>> arch/arm64/include/asm/alternative-macros.h | 2 +- >>> arch/arm64/include/asm/insn.h | 5 +---- >> >> Looks like arch/arm64/include/asm/insn-def.h is missing from this patch? >> >> If I add one with just the two deleted lines plus a header guard, the >> build passes. >> >> Tested-by: Nathan Chancellor <nathan@kernel.org> > > Whoops; that should have been as below. > > Was that the same as you tested? Yes, that is exactly what I did so the tag should still be good. Cheers, Nathan > Thanks, > Mark. > > ---->8---- > From 622fd784c57423b1a276fbbfb270b84839e3afa8 Mon Sep 17 00:00:00 2001 > From: Mark Rutland <mark.rutland@arm.com> > Date: Fri, 18 Jun 2021 16:11:22 +0100 > Subject: [PATCH] arm64: insn: avoid circular include dependency > > Nathan reports that when building with CONFIG_LTO_CLANG_THIN=y, the > build fails due to BUILD_BUG_ON() not being defined before its uss in > <asm/insn.h>. > > The problem is that with LTO, we patch READ_ONCE(), and <asm/rwonce.h> > includes <asm/insn.h>, creating a circular include chain: > > <linux/build_bug.h> > <linux/compiler.h> > <asm/rwonce.h> > <asm/alternative-macros.h> > <asm/insn.h> > <linux/build-bug.h> > > ... and so when <asm/insn.h> includes <linux/build_bug.h>, none of the > BUILD_BUG* definitions have happened yet. > > To avoid this, let's move AARCH64_INSN_SIZE into a header without any > dependencies, such that it can always be safely included. At the same > time, avoid including <asm/alternative.h> in <asm/insn.h>, which should > no longer be necessary (and doesn't make sense when insn.h is consumed > by userspace). > > Reported-by: Nathan Chancellor <nathan@kernel.org> > Signed-off-by: Mark Rutland <mark.rutland@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will@kernel.org> > --- > arch/arm64/include/asm/alternative-macros.h | 2 +- > arch/arm64/include/asm/insn-def.h | 9 +++++++++ > arch/arm64/include/asm/insn.h | 5 +---- > 3 files changed, 11 insertions(+), 5 deletions(-) > create mode 100644 arch/arm64/include/asm/insn-def.h > > diff --git a/arch/arm64/include/asm/alternative-macros.h b/arch/arm64/include/asm/alternative-macros.h > index 703fbf310b79..eba3173a2a2c 100644 > --- a/arch/arm64/include/asm/alternative-macros.h > +++ b/arch/arm64/include/asm/alternative-macros.h > @@ -3,7 +3,7 @@ > #define __ASM_ALTERNATIVE_MACROS_H > > #include <asm/cpucaps.h> > -#include <asm/insn.h> > +#include <asm/insn-def.h> > > #define ARM64_CB_PATCH ARM64_NCAPS > > diff --git a/arch/arm64/include/asm/insn-def.h b/arch/arm64/include/asm/insn-def.h > new file mode 100644 > index 000000000000..2c075f615c6a > --- /dev/null > +++ b/arch/arm64/include/asm/insn-def.h > @@ -0,0 +1,9 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > + > +#ifndef __ASM_INSN_DEF_H > +#define __ASM_INSN_DEF_H > + > +/* A64 instructions are always 32 bits. */ > +#define AARCH64_INSN_SIZE 4 > + > +#endif /* __ASM_INSN_DEF_H */ > diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h > index 1430b4973039..6b776c8667b2 100644 > --- a/arch/arm64/include/asm/insn.h > +++ b/arch/arm64/include/asm/insn.h > @@ -10,10 +10,7 @@ > #include <linux/build_bug.h> > #include <linux/types.h> > > -#include <asm/alternative.h> > - > -/* A64 instructions are always 32 bits. */ > -#define AARCH64_INSN_SIZE 4 > +#include <asm/insn-def.h> > > #ifndef __ASSEMBLY__ > /* >
diff --git a/arch/arm64/include/asm/alternative-macros.h b/arch/arm64/include/asm/alternative-macros.h index 8a078fc662ac..703fbf310b79 100644 --- a/arch/arm64/include/asm/alternative-macros.h +++ b/arch/arm64/include/asm/alternative-macros.h @@ -3,12 +3,10 @@ #define __ASM_ALTERNATIVE_MACROS_H #include <asm/cpucaps.h> +#include <asm/insn.h> #define ARM64_CB_PATCH ARM64_NCAPS -/* A64 instructions are always 32 bits. */ -#define AARCH64_INSN_SIZE 4 - #ifndef __ASSEMBLY__ #include <linux/stringify.h> diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h index a6f3f45fc46f..1430b4973039 100644 --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -12,6 +12,9 @@ #include <asm/alternative.h> +/* A64 instructions are always 32 bits. */ +#define AARCH64_INSN_SIZE 4 + #ifndef __ASSEMBLY__ /* * ARM Architecture Reference Manual for ARMv8 Profile-A, Issue A.a diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index cf8df032b9c3..894edda8cc85 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -8,6 +8,7 @@ #define __ARM_KVM_ASM_H__ #include <asm/hyp_image.h> +#include <asm/insn.h> #include <asm/virt.h> #define ARM_EXIT_WITH_SERROR_BIT 31 diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index efed2830d141..16d35cfffcea 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -76,6 +76,7 @@ #include <asm/cpufeature.h> #include <asm/cpu_ops.h> #include <asm/fpsimd.h> +#include <asm/insn.h> #include <asm/kvm_host.h> #include <asm/mmu_context.h> #include <asm/mte.h> diff --git a/arch/arm64/kernel/patching.c b/arch/arm64/kernel/patching.c index 7aa55b33c8c7..9a6edb9c48c7 100644 --- a/arch/arm64/kernel/patching.c +++ b/arch/arm64/kernel/patching.c @@ -8,6 +8,7 @@ #include <asm/cacheflush.h> #include <asm/fixmap.h> +#include <asm/insn.h> #include <asm/kprobes.h> #include <asm/patching.h> #include <asm/sections.h> diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 48ff6fb888e0..8f66072fa5cb 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -36,6 +36,7 @@ #include <asm/esr.h> #include <asm/exception.h> #include <asm/extable.h> +#include <asm/insn.h> #include <asm/kprobes.h> #include <asm/patching.h> #include <asm/traps.h> diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index f7b194878a99..dd5000da18b8 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -16,6 +16,7 @@ #include <asm/byteorder.h> #include <asm/cacheflush.h> #include <asm/debug-monitors.h> +#include <asm/insn.h> #include <asm/set_memory.h> #include "bpf_jit.h"
For histroical reasons, we define AARCH64_INSN_SIZE in <asm/alternative-macros.h>, but it would make more sense to do so in <asm/insn.h>. Let's move it into <asm/insn.h>, and add the necessary include directives for this. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> --- arch/arm64/include/asm/alternative-macros.h | 4 +--- arch/arm64/include/asm/insn.h | 3 +++ arch/arm64/include/asm/kvm_asm.h | 1 + arch/arm64/kernel/cpufeature.c | 1 + arch/arm64/kernel/patching.c | 1 + arch/arm64/kernel/traps.c | 1 + arch/arm64/net/bpf_jit_comp.c | 1 + 7 files changed, 9 insertions(+), 3 deletions(-)