Re: [RFC][PATCH v3 1/5] sparc64: Fix asm/percpu.h build error
On Thu, Jun 04, 2020 at 06:57:03PM +0200, Peter Zijlstra wrote:
> I think I see, what happens is that these headers end up in the VDSO
> build, and that doesn't have these CFLAGS, because userspace.
>
> Let me see what to do about that.
I feel like the below is cheating, but it's the best I could find :/
VDSO including kernel headers and the utter maze that our kernel headers
are makes it really hard to untangle :/
This builds sparc64-defconfig and sparc64-all{no,mod}config.
Dave, does this work for you, or should I try hardder?
---
arch/sparc/include/asm/percpu_64.h | 2 ++
arch/sparc/include/asm/trap_block.h | 2 ++
2 files changed, 4 insertions(+)
diff --git a/arch/sparc/include/asm/percpu_64.h
b/arch/sparc/include/asm/percpu_64.h
index 32ef6f05cc565..a8786a4b90b6b 100644
--- a/arch/sparc/include/asm/percpu_64.h
+++ b/arch/sparc/include/asm/percpu_64.h
@@ -4,7 +4,9 @@
#include
+#ifndef BUILD_VDSO
register unsigned long __local_per_cpu_offset asm("g5");
+#endif
#ifdef CONFIG_SMP
diff --git a/arch/sparc/include/asm/trap_block.h
b/arch/sparc/include/asm/trap_block.h
index 0f6d0c4f66838..ace0d48e837e5 100644
--- a/arch/sparc/include/asm/trap_block.h
+++ b/arch/sparc/include/asm/trap_block.h
@@ -2,6 +2,8 @@
#ifndef _SPARC_TRAP_BLOCK_H
#define _SPARC_TRAP_BLOCK_H
+#include
+
#include
#include
Re: [RFC][PATCH v3 1/5] sparc64: Fix asm/percpu.h build error
On Fri, May 29, 2020 at 04:29:17PM -0700, David Miller wrote:
> From: Peter Zijlstra
> Date: Fri, 29 May 2020 23:35:51 +0200
>
> > ../arch/sparc/include/asm/percpu_64.h:7:24: warning: call-clobbered
> > register used for global register variable
> > register unsigned long __local_per_cpu_offset asm("g5");
>
> The "-ffixed-g5" option on the command line tells gcc that we are
> using 'g5' as a fixed register, so some part of your build isn't using
> the:
>
> KBUILD_CFLAGS += -ffixed-g4 -ffixed-g5 -fcall-used-g7 -Wno-sign-compare
>
> from arch/sparc/Makefile for some reason.
Thanks, that was the clue I needed.
I think I see, what happens is that these headers end up in the VDSO
build, and that doesn't have these CFLAGS, because userspace.
Let me see what to do about that.
Re: [RFC][PATCH v3 1/5] sparc64: Fix asm/percpu.h build error
From: Peter Zijlstra
Date: Fri, 29 May 2020 23:35:51 +0200
> ../arch/sparc/include/asm/percpu_64.h:7:24: warning: call-clobbered register
> used for global register variable
> register unsigned long __local_per_cpu_offset asm("g5");
The "-ffixed-g5" option on the command line tells gcc that we are
using 'g5' as a fixed register, so some part of your build isn't using
the:
KBUILD_CFLAGS += -ffixed-g4 -ffixed-g5 -fcall-used-g7 -Wno-sign-compare
from arch/sparc/Makefile for some reason.
[RFC][PATCH v3 1/5] sparc64: Fix asm/percpu.h build error
In order to break a header dependency between lockdep and task_struct,
I need per-cpu stuff from lockdep.
Including from lockdep.h gives a build error, this
patch cures that, but results in the following warning:
../arch/sparc/include/asm/percpu_64.h:7:24: warning: call-clobbered register
used for global register variable
register unsigned long __local_per_cpu_offset asm("g5");
But i've no idea how to fix that :/ but it does build.
Not-Signed-off-by: Peter Zijlstra (Intel)
---
arch/sparc/include/asm/trap_block.h |2 ++
1 file changed, 2 insertions(+)
--- a/arch/sparc/include/asm/trap_block.h
+++ b/arch/sparc/include/asm/trap_block.h
@@ -2,6 +2,8 @@
#ifndef _SPARC_TRAP_BLOCK_H
#define _SPARC_TRAP_BLOCK_H
+#include
+
#include
#include
