Messages in this thread | | | From | Huacai Chen <> | Date | Sun, 28 Aug 2022 22:15:24 +0800 | Subject | Re: [PATCH 0/8] LoongArch: Support toolchain with new relocation types |
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Hi, Ruoyao,
On Sun, Aug 28, 2022 at 1:55 AM Xi Ruoyao <xry111@xry111.site> wrote: > > The version 2.00 of LoongArch ELF ABI specification introduced new > relocation types, and the development tree of Binutils and GCC has > started to use them. If the kernel is built with the latest snapshot of > Binutils or GCC, it will fail to load the modules because of unrecognized > relocation types in modules. > > Add support for GOT and new relocation types for the module loader, so > the kernel (with modules) can be built with the "normal" code model and > function properly. > > This series does not break the compatibility with old toolchain using > stack-based relocation types, so with the patches applied the kernel can > be be built with both old and new toolchains. > > Tested by building the kernel with the following combinations: > > - GCC 12 and Binutils 2.39 > - GCC 12 and Binutils trunk > - GCC trunk and Binutils trunk > > and running the builds with 35 in-tree modules loaded, and loading one > module with 20 GOT loads and a per-CPU variable (loaded addresses > verified by comparing with /proc/kallsyms). > > This superseds "LoongArch: Support new relocation types" series. I > don't make it a "v5" because too much things have changed so it's better > to treat this as a new series. 1, You can still call it v5, even if it has changed a lot; 2, In my opinion, patch 4,5,7,8 can be combined, but I don't insist if you have a good reason to separate. 3, If possible, I still prefer to remove old relocation types support, in order to make life easier, especially for objtool that is queued for upstream.
Huacai
> > Xi Ruoyao (8): > LoongArch: Add CONFIG_CC_HAS_EXPLICIT_RELOCS > LoongArch: Only use -Wa,-mla-* options for > !CONFIG_CC_HAS_EXPLICIT_RELOCS > LoongArch: Define ELF relocation types added in v2.00 ABI > LoongArch: Support R_LARCH_B26 in modules > LoongArch: Support R_LARCH_ABS* in modules > LoongArch: Use model("extreme") attribute for per-CPU variables in > module if CONFIG_CC_HAS_EXPLICIT_RELOCS > LoongArch: Support R_LARCH_PCALA* in modules > LoongArch: Support R_LARCH_GOT_PC* in modules > > arch/loongarch/Kconfig | 3 + > arch/loongarch/Makefile | 15 ++- > arch/loongarch/include/asm/elf.h | 37 +++++++ > arch/loongarch/include/asm/module.h | 23 ++++ > arch/loongarch/include/asm/module.lds.h | 1 + > arch/loongarch/include/asm/percpu.h | 13 +++ > arch/loongarch/kernel/head.S | 10 +- > arch/loongarch/kernel/module-sections.c | 56 +++++++++- > arch/loongarch/kernel/module.c | 138 +++++++++++++++++++++++- > 9 files changed, 285 insertions(+), 11 deletions(-) > > -- > 2.37.0 >
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