[PATCH] riscv: fix build with binutils 2.38

[PATCH] riscv: fix build with binutils 2.38

[Aurelien Jarno]

From version 2.38, binutils default to ISA spec version 20191213. This
means that the csr read/write (csrr*/csrw*) instructions and fence.i
instruction has separated from the `I` extension, become two standalone
extensions: Zicsr and Zifencei. As the kernel uses those instruction,
this causes the following build failure:

  CC      arch/riscv/kernel/vdso/vgettimeofday.o
  <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h: Assembler messages:
  <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
  <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
  <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
  <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'

The fix is to specify those extensions explicitely in -march. However as
older binutils version do not support this, we first need to detect
that.

Cc: stable@vger.kernel.org # 4.15+
Cc: Kito Cheng <kito.cheng@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---
 arch/riscv/Makefile | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index 8a107ed18b0d..7d81102cffd4 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -50,6 +50,12 @@ riscv-march-$(CONFIG_ARCH_RV32I)	:= rv32ima
 riscv-march-$(CONFIG_ARCH_RV64I)	:= rv64ima
 riscv-march-$(CONFIG_FPU)		:= $(riscv-march-y)fd
 riscv-march-$(CONFIG_RISCV_ISA_C)	:= $(riscv-march-y)c
+
+# Newer binutils versions default to ISA spec version 20191213 which moves some
+# instructions from the I extension to the Zicsr and Zifencei extensions.
+toolchain-need-zicsr-zifencei := $(call cc-option-yn, -march=$(riscv-march-y)_zicsr_zifencei)
+riscv-march-$(toolchain-need-zicsr-zifencei) := $(riscv-march-y)_zicsr_zifencei
+
 KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y))
 KBUILD_AFLAGS += -march=$(riscv-march-y)
 
-- 
2.34.1

Re: [PATCH] riscv: fix build with binutils 2.38

[Alexandre Ghiti]

Hi Aurelien,

On Wed, Jan 26, 2022 at 6:41 PM Aurelien Jarno <aurelien@aurel32.net> wrote:
>
> From version 2.38, binutils default to ISA spec version 20191213. This
> means that the csr read/write (csrr*/csrw*) instructions and fence.i
> instruction has separated from the `I` extension, become two standalone
> extensions: Zicsr and Zifencei. As the kernel uses those instruction,
> this causes the following build failure:
>
>   CC      arch/riscv/kernel/vdso/vgettimeofday.o
>   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h: Assembler messages:
>   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
>   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
>   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
>   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
>
> The fix is to specify those extensions explicitely in -march. However as
> older binutils version do not support this, we first need to detect
> that.
>
> Cc: stable@vger.kernel.org # 4.15+
> Cc: Kito Cheng <kito.cheng@gmail.com>
> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
> ---
>  arch/riscv/Makefile | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
> index 8a107ed18b0d..7d81102cffd4 100644
> --- a/arch/riscv/Makefile
> +++ b/arch/riscv/Makefile
> @@ -50,6 +50,12 @@ riscv-march-$(CONFIG_ARCH_RV32I)     := rv32ima
>  riscv-march-$(CONFIG_ARCH_RV64I)       := rv64ima
>  riscv-march-$(CONFIG_FPU)              := $(riscv-march-y)fd
>  riscv-march-$(CONFIG_RISCV_ISA_C)      := $(riscv-march-y)c
> +
> +# Newer binutils versions default to ISA spec version 20191213 which moves some
> +# instructions from the I extension to the Zicsr and Zifencei extensions.
> +toolchain-need-zicsr-zifencei := $(call cc-option-yn, -march=$(riscv-march-y)_zicsr_zifencei)
> +riscv-march-$(toolchain-need-zicsr-zifencei) := $(riscv-march-y)_zicsr_zifencei
> +
>  KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y))
>  KBUILD_AFLAGS += -march=$(riscv-march-y)
>
> --
> 2.34.1
>
>

That fixes our kernel build with the new binutils, so you can add:

Tested-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>

Thanks for working on this!

Alex

> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv

Re: [PATCH] riscv: fix build with binutils 2.38

[Palmer Dabbelt]

On Wed, 26 Jan 2022 09:14:42 PST (-0800), aurelien@aurel32.net wrote:
> From version 2.38, binutils default to ISA spec version 20191213. This
> means that the csr read/write (csrr*/csrw*) instructions and fence.i
> instruction has separated from the `I` extension, become two standalone
> extensions: Zicsr and Zifencei. As the kernel uses those instruction,
> this causes the following build failure:
>
>   CC      arch/riscv/kernel/vdso/vgettimeofday.o
>   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h: Assembler messages:
>   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
>   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
>   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
>   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
>
> The fix is to specify those extensions explicitely in -march. However as
> older binutils version do not support this, we first need to detect
> that.
>
> Cc: stable@vger.kernel.org # 4.15+
> Cc: Kito Cheng <kito.cheng@gmail.com>
> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
> ---
>  arch/riscv/Makefile | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
> index 8a107ed18b0d..7d81102cffd4 100644
> --- a/arch/riscv/Makefile
> +++ b/arch/riscv/Makefile
> @@ -50,6 +50,12 @@ riscv-march-$(CONFIG_ARCH_RV32I)	:= rv32ima
>  riscv-march-$(CONFIG_ARCH_RV64I)	:= rv64ima
>  riscv-march-$(CONFIG_FPU)		:= $(riscv-march-y)fd
>  riscv-march-$(CONFIG_RISCV_ISA_C)	:= $(riscv-march-y)c
> +
> +# Newer binutils versions default to ISA spec version 20191213 which moves some
> +# instructions from the I extension to the Zicsr and Zifencei extensions.
> +toolchain-need-zicsr-zifencei := $(call cc-option-yn, -march=$(riscv-march-y)_zicsr_zifencei)
> +riscv-march-$(toolchain-need-zicsr-zifencei) := $(riscv-march-y)_zicsr_zifencei
> +
>  KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y))
>  KBUILD_AFLAGS += -march=$(riscv-march-y)

Thanks, this is on fixes.  It's CC stable, but doesn't have a "Fixes" 
tag -- I did that on purpose as this isn't really fixing a bug in Linux 
so I'm not sure it's right to point at a particular patch, but I'm not 
sure how that will play with the stable tree.

Re: [PATCH] riscv: fix build with binutils 2.38

[Greg KH]

On Thu, Feb 10, 2022 at 09:40:22AM -0800, Palmer Dabbelt wrote:
> On Wed, 26 Jan 2022 09:14:42 PST (-0800), aurelien@aurel32.net wrote:
> > From version 2.38, binutils default to ISA spec version 20191213. This
> > means that the csr read/write (csrr*/csrw*) instructions and fence.i
> > instruction has separated from the `I` extension, become two standalone
> > extensions: Zicsr and Zifencei. As the kernel uses those instruction,
> > this causes the following build failure:
> > 
> >   CC      arch/riscv/kernel/vdso/vgettimeofday.o
> >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h: Assembler messages:
> >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> > 
> > The fix is to specify those extensions explicitely in -march. However as
> > older binutils version do not support this, we first need to detect
> > that.
> > 
> > Cc: stable@vger.kernel.org # 4.15+
> > Cc: Kito Cheng <kito.cheng@gmail.com>
> > Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
> > ---
> >  arch/riscv/Makefile | 6 ++++++
> >  1 file changed, 6 insertions(+)
> > 
> > diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
> > index 8a107ed18b0d..7d81102cffd4 100644
> > --- a/arch/riscv/Makefile
> > +++ b/arch/riscv/Makefile
> > @@ -50,6 +50,12 @@ riscv-march-$(CONFIG_ARCH_RV32I)	:= rv32ima
> >  riscv-march-$(CONFIG_ARCH_RV64I)	:= rv64ima
> >  riscv-march-$(CONFIG_FPU)		:= $(riscv-march-y)fd
> >  riscv-march-$(CONFIG_RISCV_ISA_C)	:= $(riscv-march-y)c
> > +
> > +# Newer binutils versions default to ISA spec version 20191213 which moves some
> > +# instructions from the I extension to the Zicsr and Zifencei extensions.
> > +toolchain-need-zicsr-zifencei := $(call cc-option-yn, -march=$(riscv-march-y)_zicsr_zifencei)
> > +riscv-march-$(toolchain-need-zicsr-zifencei) := $(riscv-march-y)_zicsr_zifencei
> > +
> >  KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y))
> >  KBUILD_AFLAGS += -march=$(riscv-march-y)
> 
> Thanks, this is on fixes.  It's CC stable, but doesn't have a "Fixes" tag --
> I did that on purpose as this isn't really fixing a bug in Linux so I'm not
> sure it's right to point at a particular patch, but I'm not sure how that
> will play with the stable tree.

I will backport it as far back as it easily goes to, and then forget
about it :)

If you have a Fixes: tag, and it doesn't properly backport that far,
then you will get a "FAILED:" email notifying you about it.

hope that helps explain things,

greg k-h

Re: [PATCH] riscv: fix build with binutils 2.38

[Marc Kleine-Budde]

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On 26.01.2022 18:14:42, Aurelien Jarno wrote:
> From version 2.38, binutils default to ISA spec version 20191213. This
> means that the csr read/write (csrr*/csrw*) instructions and fence.i
> instruction has separated from the `I` extension, become two standalone
> extensions: Zicsr and Zifencei. As the kernel uses those instruction,
> this causes the following build failure:
> 
>   CC      arch/riscv/kernel/vdso/vgettimeofday.o
>   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h: Assembler messages:
>   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
>   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
>   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
>   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> 
> The fix is to specify those extensions explicitely in -march. However as
> older binutils version do not support this, we first need to detect
> that.
> 
> Cc: stable@vger.kernel.org # 4.15+
> Cc: Kito Cheng <kito.cheng@gmail.com>
> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
> ---
>  arch/riscv/Makefile | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
> index 8a107ed18b0d..7d81102cffd4 100644
> --- a/arch/riscv/Makefile
> +++ b/arch/riscv/Makefile
> @@ -50,6 +50,12 @@ riscv-march-$(CONFIG_ARCH_RV32I)	:= rv32ima
>  riscv-march-$(CONFIG_ARCH_RV64I)	:= rv64ima
>  riscv-march-$(CONFIG_FPU)		:= $(riscv-march-y)fd
>  riscv-march-$(CONFIG_RISCV_ISA_C)	:= $(riscv-march-y)c
> +
> +# Newer binutils versions default to ISA spec version 20191213 which moves some
> +# instructions from the I extension to the Zicsr and Zifencei extensions.
> +toolchain-need-zicsr-zifencei := $(call cc-option-yn, -march=$(riscv-march-y)_zicsr_zifencei)
> +riscv-march-$(toolchain-need-zicsr-zifencei) := $(riscv-march-y)_zicsr_zifencei
> +
>  KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y))
>  KBUILD_AFLAGS += -march=$(riscv-march-y)

I'm on current linus/master, this change breaks on current Debian
testing with:

| make: Leaving directory 'linux'
|   SYNC    include/config/auto.conf.cmd
|   GEN     Makefile
|   GEN     Makefile
|   CC      scripts/mod/empty.o
|   CHECK   linux/scripts/mod/empty.c
| invalid argument to '-march': '_zicsr_zifencei'

Used components:

| $ riscv64-linux-gnu-gcc -v
| Using built-in specs.
| COLLECT_GCC=/usr/bin/riscv64-linux-gnu-gcc
| COLLECT_LTO_WRAPPER=/usr/lib/gcc-cross/riscv64-linux-gnu/11/lto-wrapper
| Target: riscv64-linux-gnu
| Configured with: ../src/configure -v --with-pkgversion='Debian 11.2.0-9' --with-bugurl=file:///usr/share/doc/gcc-11/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-11 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-libitm --disable-libquadmath --disable-libquadmath-support --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --without-target-system-zlib --enable-multiarch --disable-werror --disable-multilib --with-arch=rv64imafdc --with-abi=lp64d --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=riscv64-linux-gnu --program-prefix=riscv64-linux-gnu- --includedir=/usr/riscv64-linux-gnu/include --with-build-config=bootstrap-lto-lean --enable-link-serialization=2
| Thread model: posix
| Supported LTO compression algorithms: zlib zstd
| gcc version 11.2.0 (Debian 11.2.0-9) 
| $ riscv64-linux-gnu-ld -v
| GNU ld (GNU Binutils for Debian) 2.38

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

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Re: [PATCH] riscv: fix build with binutils 2.38

[Marc Kleine-Budde]

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On 31.03.2022 12:32:47, Marc Kleine-Budde wrote:
> On 26.01.2022 18:14:42, Aurelien Jarno wrote:
> > From version 2.38, binutils default to ISA spec version 20191213. This
> > means that the csr read/write (csrr*/csrw*) instructions and fence.i
> > instruction has separated from the `I` extension, become two standalone
> > extensions: Zicsr and Zifencei. As the kernel uses those instruction,
> > this causes the following build failure:
> > 
> >   CC      arch/riscv/kernel/vdso/vgettimeofday.o
> >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h: Assembler messages:
> >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> > 
> > The fix is to specify those extensions explicitely in -march. However as
> > older binutils version do not support this, we first need to detect
> > that.
> > 
> > Cc: stable@vger.kernel.org # 4.15+
> > Cc: Kito Cheng <kito.cheng@gmail.com>
> > Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
> > ---
> >  arch/riscv/Makefile | 6 ++++++
> >  1 file changed, 6 insertions(+)
> > 
> > diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
> > index 8a107ed18b0d..7d81102cffd4 100644
> > --- a/arch/riscv/Makefile
> > +++ b/arch/riscv/Makefile
> > @@ -50,6 +50,12 @@ riscv-march-$(CONFIG_ARCH_RV32I)	:= rv32ima
> >  riscv-march-$(CONFIG_ARCH_RV64I)	:= rv64ima
> >  riscv-march-$(CONFIG_FPU)		:= $(riscv-march-y)fd
> >  riscv-march-$(CONFIG_RISCV_ISA_C)	:= $(riscv-march-y)c
> > +
> > +# Newer binutils versions default to ISA spec version 20191213 which moves some
> > +# instructions from the I extension to the Zicsr and Zifencei extensions.
> > +toolchain-need-zicsr-zifencei := $(call cc-option-yn, -march=$(riscv-march-y)_zicsr_zifencei)
> > +riscv-march-$(toolchain-need-zicsr-zifencei) := $(riscv-march-y)_zicsr_zifencei
> > +
> >  KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y))
> >  KBUILD_AFLAGS += -march=$(riscv-march-y)
> 
> I'm on current linus/master, this change breaks on current Debian
> testing with:
> 
> | make: Leaving directory 'linux'
> |   SYNC    include/config/auto.conf.cmd
> |   GEN     Makefile
> |   GEN     Makefile
> |   CC      scripts/mod/empty.o
> |   CHECK   linux/scripts/mod/empty.c
      ^^^^^
It's actually "sparse" that breaks
      
> | invalid argument to '-march': '_zicsr_zifencei'

| $ sparse --version
| 0.6.4 (Debian: 0.6.4-2)

Compiling without "C=1" for now.

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

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Re: [PATCH] riscv: fix build with binutils 2.38

[Marc Kleine-Budde]

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Cc += linux-sparse, Uwe, Luc Van Oostenryck

tl;dr:

A recent change in the kernel regarding the riscv -march handling breaks
current sparse.

On 31.03.2022 12:39:14, Marc Kleine-Budde wrote:
> On 31.03.2022 12:32:47, Marc Kleine-Budde wrote:
> > On 26.01.2022 18:14:42, Aurelien Jarno wrote:
> > > From version 2.38, binutils default to ISA spec version 20191213. This
> > > means that the csr read/write (csrr*/csrw*) instructions and fence.i
> > > instruction has separated from the `I` extension, become two standalone
> > > extensions: Zicsr and Zifencei. As the kernel uses those instruction,
> > > this causes the following build failure:
> > > 
> > >   CC      arch/riscv/kernel/vdso/vgettimeofday.o
> > >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h: Assembler messages:
> > >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> > >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> > >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> > >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> > > 
> > > The fix is to specify those extensions explicitely in -march. However as
> > > older binutils version do not support this, we first need to detect
> > > that.
> > > 
> > > Cc: stable@vger.kernel.org # 4.15+
> > > Cc: Kito Cheng <kito.cheng@gmail.com>
> > > Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
> > > ---
> > >  arch/riscv/Makefile | 6 ++++++
> > >  1 file changed, 6 insertions(+)
> > > 
> > > diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
> > > index 8a107ed18b0d..7d81102cffd4 100644
> > > --- a/arch/riscv/Makefile
> > > +++ b/arch/riscv/Makefile
> > > @@ -50,6 +50,12 @@ riscv-march-$(CONFIG_ARCH_RV32I)	:= rv32ima
> > >  riscv-march-$(CONFIG_ARCH_RV64I)	:= rv64ima
> > >  riscv-march-$(CONFIG_FPU)		:= $(riscv-march-y)fd
> > >  riscv-march-$(CONFIG_RISCV_ISA_C)	:= $(riscv-march-y)c
> > > +
> > > +# Newer binutils versions default to ISA spec version 20191213 which moves some
> > > +# instructions from the I extension to the Zicsr and Zifencei extensions.
> > > +toolchain-need-zicsr-zifencei := $(call cc-option-yn, -march=$(riscv-march-y)_zicsr_zifencei)
> > > +riscv-march-$(toolchain-need-zicsr-zifencei) := $(riscv-march-y)_zicsr_zifencei
> > > +
> > >  KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y))
> > >  KBUILD_AFLAGS += -march=$(riscv-march-y)
> > 
> > I'm on current linus/master, this change breaks on current Debian
> > testing with:
> > 
> > | make: Leaving directory 'linux'
> > |   SYNC    include/config/auto.conf.cmd
> > |   GEN     Makefile
> > |   GEN     Makefile
> > |   CC      scripts/mod/empty.o
> > |   CHECK   linux/scripts/mod/empty.c
>       ^^^^^
> It's actually "sparse" that breaks
>       
> > | invalid argument to '-march': '_zicsr_zifencei'
> 
> | $ sparse --version
> | 0.6.4 (Debian: 0.6.4-2)

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

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Re: [PATCH] riscv: fix build with binutils 2.38

[Aurelien Jarno]

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Hi,

On 2022-03-31 12:51, Marc Kleine-Budde wrote:
> Cc += linux-sparse, Uwe, Luc Van Oostenryck
> 
> tl;dr:
> 
> A recent change in the kernel regarding the riscv -march handling breaks
> current sparse.
> 
> On 31.03.2022 12:39:14, Marc Kleine-Budde wrote:
> > On 31.03.2022 12:32:47, Marc Kleine-Budde wrote:
> > > On 26.01.2022 18:14:42, Aurelien Jarno wrote:
> > > > From version 2.38, binutils default to ISA spec version 20191213. This
> > > > means that the csr read/write (csrr*/csrw*) instructions and fence.i
> > > > instruction has separated from the `I` extension, become two standalone
> > > > extensions: Zicsr and Zifencei. As the kernel uses those instruction,
> > > > this causes the following build failure:
> > > > 
> > > >   CC      arch/riscv/kernel/vdso/vgettimeofday.o
> > > >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h: Assembler messages:
> > > >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> > > >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> > > >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> > > >   <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
> > > > 
> > > > The fix is to specify those extensions explicitely in -march. However as
> > > > older binutils version do not support this, we first need to detect
> > > > that.
> > > > 
> > > > Cc: stable@vger.kernel.org # 4.15+
> > > > Cc: Kito Cheng <kito.cheng@gmail.com>
> > > > Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
> > > > ---
> > > >  arch/riscv/Makefile | 6 ++++++
> > > >  1 file changed, 6 insertions(+)
> > > > 
> > > > diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
> > > > index 8a107ed18b0d..7d81102cffd4 100644
> > > > --- a/arch/riscv/Makefile
> > > > +++ b/arch/riscv/Makefile
> > > > @@ -50,6 +50,12 @@ riscv-march-$(CONFIG_ARCH_RV32I)	:= rv32ima
> > > >  riscv-march-$(CONFIG_ARCH_RV64I)	:= rv64ima
> > > >  riscv-march-$(CONFIG_FPU)		:= $(riscv-march-y)fd
> > > >  riscv-march-$(CONFIG_RISCV_ISA_C)	:= $(riscv-march-y)c
> > > > +
> > > > +# Newer binutils versions default to ISA spec version 20191213 which moves some
> > > > +# instructions from the I extension to the Zicsr and Zifencei extensions.
> > > > +toolchain-need-zicsr-zifencei := $(call cc-option-yn, -march=$(riscv-march-y)_zicsr_zifencei)
> > > > +riscv-march-$(toolchain-need-zicsr-zifencei) := $(riscv-march-y)_zicsr_zifencei
> > > > +
> > > >  KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y))
> > > >  KBUILD_AFLAGS += -march=$(riscv-march-y)
> > > 
> > > I'm on current linus/master, this change breaks on current Debian
> > > testing with:
> > > 
> > > | make: Leaving directory 'linux'
> > > |   SYNC    include/config/auto.conf.cmd
> > > |   GEN     Makefile
> > > |   GEN     Makefile
> > > |   CC      scripts/mod/empty.o
> > > |   CHECK   linux/scripts/mod/empty.c
> >       ^^^^^
> > It's actually "sparse" that breaks
> >       
> > > | invalid argument to '-march': '_zicsr_zifencei'
> > 
> > | $ sparse --version
> > | 0.6.4 (Debian: 0.6.4-2)

I confirm the issue. To make things clear, it's not a Makefile issue,
sparse get passed the correct -march=rv64ima_zicsr_zifencei value, and
only display the part it can't parse.

On the medium/long term, sparse should get fixed to support those
extensions. On the short term, we need to find a way to get different
flags for sparse than for as/gcc.

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                 http://www.aurel32.net

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Re: [PATCH] riscv: fix build with binutils 2.38

[Linus Torvalds]

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On Thu, Mar 31, 2022 at 3:51 AM Marc Kleine-Budde <mkl@pengutronix.de> wrote:
>
> Cc += linux-sparse, Uwe, Luc Van Oostenryck
>
> tl;dr:
>
> A recent change in the kernel regarding the riscv -march handling breaks
> current sparse.

Gaah. Normally sparse doesn't even look at the -march flag, but for
riscv it does, because it's meaningful for the predefined macros.

Maybe that 'die()' shouldn't be so fatal. And maybe add a few more
extensions (but ignore them) to the parsing.

Something ENTIRELY UNTESTED like the attached.

               Linus

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 target-riscv.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/target-riscv.c b/target-riscv.c
index 6d9113c1..201ac375 100644
--- a/target-riscv.c
+++ b/target-riscv.c
@@ -3,6 +3,7 @@
 #include "target.h"
 #include "machine.h"
 #include <string.h>
+#include <stdio.h>
 
 #define RISCV_32BIT	(1 << 0)
 #define RISCV_64BIT	(1 << 1)
@@ -47,6 +48,12 @@ static void parse_march_riscv(const char *arg)
 		{ "n",		0 },
 		{ "h",		0 },
 		{ "s",		0 },
+		{ "i",		0 },
+		{ "e",		0 },
+		{ "_",		0 },
+		{ "Counters",	0 },
+		{ "Zicsr",	0 },
+		{ "Zifencei",	0 },
 	};
 	int i;
 
@@ -60,7 +67,10 @@ static void parse_march_riscv(const char *arg)
 			goto ext;
 		}
 	}
-	die("invalid argument to '-march': '%s'\n", arg);
+
+unknown:
+	fprintf(stderr, "WARNING: invalid argument to '-march': '%s'\n", arg);
+	return;
 
 ext:
 	for (i = 0; i < ARRAY_SIZE(extensions); i++) {
@@ -73,7 +83,7 @@ ext:
 		}
 	}
 	if (arg[0])
-		die("invalid argument to '-march': '%s'\n", arg);
+		goto unknown;
 }
 
 static void init_riscv(const struct target *self)

Re: [PATCH] riscv: fix build with binutils 2.38

[Palmer Dabbelt]

On Thu, 31 Mar 2022 11:16:53 PDT (-0700), Linus Torvalds wrote:
> On Thu, Mar 31, 2022 at 3:51 AM Marc Kleine-Budde <mkl@pengutronix.de> wrote:
>>
>> Cc += linux-sparse, Uwe, Luc Van Oostenryck
>>
>> tl;dr:
>>
>> A recent change in the kernel regarding the riscv -march handling breaks
>> current sparse.

Sorry about that, looks like I'm not running sparse as part of my 
testing.  I'll add it, but it might take a bit as I'm assuming there 
will be a bunch of issues it points out.

> Gaah. Normally sparse doesn't even look at the -march flag, but for
> riscv it does, because it's meaningful for the predefined macros.
>
> Maybe that 'die()' shouldn't be so fatal. And maybe add a few more
> extensions (but ignore them) to the parsing.
>
> Something ENTIRELY UNTESTED like the attached.

Converting this to a warning seems reasonable to me, as then we're not 
as coupled to the sparse version.  The current crop of extensions don't 
set anything exciting for Linux, but there are some on the horizon that 
likely will -- hopefully having sparse in my test setup should be 
sufficient to dig those up, though.

As far as the new extension go: "Counters" isn't an ISA extension, and 
"e" defines "__riscv_32e".  It'd also be slightly saner to match on 
"_Zifencei", but that probably doesn't matter (GCC is sufficiently 
strict here).  Looks like there's also some oddities in the sparse ISA 
string parsing, I'll go clean them up as I get it running locally.

We could also stop relying on the compiler's defines, which would avoid 
this problem entirely, but IIRC that was discussed when decided to 
modify sparse in the first place and we went this way (though I don't 
remember why).  That would keep everything inside the kernel.

Re: [PATCH] riscv: fix build with binutils 2.38

[Marc Kleine-Budde]

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On 31.03.2022 11:16:53, Linus Torvalds wrote:
> On Thu, Mar 31, 2022 at 3:51 AM Marc Kleine-Budde <mkl@pengutronix.de> wrote:
> >
> > Cc += linux-sparse, Uwe, Luc Van Oostenryck
> >
> > tl;dr:
> >
> > A recent change in the kernel regarding the riscv -march handling breaks
> > current sparse.
> 
> Gaah. Normally sparse doesn't even look at the -march flag, but for
> riscv it does, because it's meaningful for the predefined macros.
> 
> Maybe that 'die()' shouldn't be so fatal. And maybe add a few more
> extensions (but ignore them) to the parsing.
> 
> Something ENTIRELY UNTESTED like the attached.

Works-for-me:

|   CHECK   /srv/work/frogger/socketcan/linux/drivers/net/can/usb/etas_es58x/es58x_core.c
| WARNING: invalid argument to '-march': 'zicsr_zifencei'

Tested-by: Marc Kleine-Budde <mkl@pengutronix.de>

Regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

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Re: [PATCH] riscv: fix build with binutils 2.38

[Linus Torvalds]

On Thu, Mar 31, 2022 at 11:53 PM Marc Kleine-Budde <mkl@pengutronix.de> wrote:
>
> | WARNING: invalid argument to '-march': 'zicsr_zifencei'

Gaah, it works but still warns because I cut-and-pasted those
zicsr/zifencei options from some random source that had them
capitalized and I didn't look closely enough at the reports.

Anyway, hopefully somebody can bother to fix up that. Possibly by
changing the strncmp to a strnicmp - but I don't know what the rules
for lower-case vs capitals are for the other options. I'm still busy
with the kernel merge window, so this gets archived on my side..

             Linus

Re: [PATCH] riscv: fix build with binutils 2.38

[Palmer Dabbelt]

On Fri, 01 Apr 2022 10:14:03 PDT (-0700), Linus Torvalds wrote:
> On Thu, Mar 31, 2022 at 11:53 PM Marc Kleine-Budde <mkl@pengutronix.de> wrote:
>>
>> | WARNING: invalid argument to '-march': 'zicsr_zifencei'
>
> Gaah, it works but still warns because I cut-and-pasted those
> zicsr/zifencei options from some random source that had them
> capitalized and I didn't look closely enough at the reports.
>
> Anyway, hopefully somebody can bother to fix up that. Possibly by
> changing the strncmp to a strnicmp - but I don't know what the rules
> for lower-case vs capitals are for the other options. I'm still busy
> with the kernel merge window, so this gets archived on my side..

I'm gluing sparse to my build tests now, so I'll sort it out (that'll 
also make sure a failure doesn't leak again).  Might not be today, but 
shouldn't take too long.