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