Messages in this thread | | | Date | Fri, 29 Jul 2022 17:47:24 +0800 | Subject | Re: [PATCH v4 0/4] LoongArch: Support new relocation types | From | WANG Xuerui <> |
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On 2022/7/29 16:38, Xi Ruoyao 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 both Binutils & GCC master branch and > my system Binutils & GCC (without new relocation type support), running > both the builds with 35 in-tree modules loaded, and loading one module > with 20 GOT loads (loaded addresses verified by comparing with > /proc/kallsyms). > > Changes from v3 to v4: > > - No code change. Reword the commit message of the 3rd patch again > based on suggestion from Huacai. > > Changes from v2 to v3: > > - Use `union loongarch_instruction` instead of explicit bit shifts > applying the relocation. Suggested by Youling. > - For R_LARCH_B26, move the alignment check before the range check to be > consistent with stack pop relocations. Suggested by Youling. > - Reword the commit message of the 3rd patch. Suggested by Huacai. > > Changes from v1 to v2: > > - Fix a stupid programming error (confusion between the number of PLT > entries and the number of GOT entries). (Bug spotted by Youling). > - Synthesize the _GLOBAL_OFFSET_TABLE_ symbol with module.lds, instead > of faking it at runtime. The 3rd patch from V1 is now merged into > the 1st patch because it would be a one-line change. (Suggested by > Jinyang). > - Keep reloc_rela_handlers[] ordered by the relocation type ID. > (Suggested by Youling). > - Remove -fplt along with -Wa,-mla-* options because it's the default. > (Suggested by Youling). > > Xi Ruoyao (4): > LoongArch: Add section of GOT for kernel module > LoongArch: Support R_LARCH_SOP_PUSH_GPREL relocation type in kernel > module > LoongArch: Remove -fplt and -Wa,-mla-* from CFLAGS > LoongArch: Support modules with new relocation types > > arch/loongarch/Makefile | 4 -- > arch/loongarch/include/asm/elf.h | 37 ++++++++++ > arch/loongarch/include/asm/module.h | 23 ++++++ > arch/loongarch/include/asm/module.lds.h | 1 + > arch/loongarch/kernel/head.S | 10 +-- > arch/loongarch/kernel/module-sections.c | 51 +++++++++++-- > arch/loongarch/kernel/module.c | 96 +++++++++++++++++++++++++ > 7 files changed, 209 insertions(+), 13 deletions(-) >
Thanks very much for the timely adaptation. I'm rebuilding my Gentoo toolchain from upstream HEAD, will test this weekend.
-- WANG "xen0n" Xuerui
Linux/LoongArch mailing list: https://lore.kernel.org/loongarch/
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