Messages in this thread | | | Date | Thu, 27 Jul 2023 00:48:28 +0800 | From | Mingzheng Xing <> | Subject | Re: [PATCH] riscv: Handle zicsr/zifencei issue between gcc and binutils |
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On 7/26/23 01:23, Nathan Chancellor wrote: > Hi Mingzheng, > > Thanks for the patch! > > On Wed, Jul 26, 2023 at 01:04:05AM +0800, Mingzheng Xing wrote: >> When compiling the kernel with the toolchain composed of GCC >= 12.1.0 and >> binutils < 2.38, default ISA spec used when building binutils and GCC, the >> following build failure will appear because the >> CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI is not turned on. >> (i.e, gcc-12.1.0 and binutils-2.36, or gcc-12.3.0 and binutils-2.37, use >> default ISA spec.) >> >> 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:79: Error: unrecognized opcode `csrr a5,0xc01' > The gift that keeps on giving :/ Yeah, but things will get better :) >> Binutils has updated the default ISA spec version, and the community has >> responded well to this[1][2][3], but it appears that this is not over yet. >> >> We also need to consider the situation of binutils < 2.38 but >> GCC >= 12.1.0, since the combination between different versions of GCC and >> binutils is not unique, which is to some extent flexible. GCC release >> 12.1.0 updated the default ISA spec version in GCC commit[4]. > I suspect this combination is not too common because binutils 2.38 came > out before GCC 12.1.0 but as you note, it is obviously possible. What > toolchain has this combination in the wild, which would be helpful for > documentation purposes? Actually, this issue was discovered during the upgrade of the distribution openEuler for RISC-V. It is a temporary phenomenon caused by inconsistent upgrade speeds of packages such as GCC and binutils. From my limited understanding, GCC and binutils are not strictly version-bound in some other distributions, so I can't rule out this issue happening in other scenarios. But once it happens it can cause problems with compiling the kernel. >> For more information, please refer to: >> >> commit 6df2a016c0c8 ("riscv: fix build with binutils 2.38") >> commit e89c2e815e76 ("riscv: Handle zicsr/zifencei issues between clang and binutils") >> >> [1]:https://groups.google.com/a/groups.riscv.org/g/sw-dev/c/aE1ZeHHCYf4 >> [2]:https://lore.kernel.org/all/20230308220842.1231003-1-conor@kernel.org >> [3]:https://lore.kernel.org/all/20230223220546.52879-1-conor@kernel.org >> [4]:https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd >> >> Signed-off-by: Mingzheng Xing<xingmingzheng@iscas.ac.cn> >> --- >> arch/riscv/Kconfig | 6 +++++- >> 1 file changed, 5 insertions(+), 1 deletion(-) >> >> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig >> index 4c07b9189c86..b49cea30f6cc 100644 >> --- a/arch/riscv/Kconfig >> +++ b/arch/riscv/Kconfig >> @@ -570,11 +570,15 @@ config TOOLCHAIN_HAS_ZIHINTPAUSE >> config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI >> def_bool y >> #https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc >> - depends on AS_IS_GNU && AS_VERSION >= 23800 >> + #https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd >> + depends on CC_IS_GCC && GCC_VERSION >= 120100 || \ >> + AS_IS_GNU && AS_VERSION >= 23800 > GCC_VERSION will be 0 for clang, so you don't need the CC_IS_GCC check. > With that change, this should be able to stay on one line: > > depends on GCC_VERSION >= 120100 || (AS_IS_GNU && AS_VERSION >= 23800) OK, I'll change it in v2.
Thanks, Mingzheng. >> help >> Newer binutils versions default to ISA spec version 20191213 which >> moves some instructions from the I extension to the Zicsr and Zifencei >> extensions. >> + Similarly, GCC release 12.1.0 has changed the default ISA spec version to >> + 20191213, so the above situation requires this option to be enabled. >> >> config TOOLCHAIN_NEEDS_OLD_ISA_SPEC >> def_bool y >> -- >> 2.34.1 >> > Cheers, > Nathan > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv
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