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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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90776dd1c4
It seems that LLVM's linker does not correctly handle variable assignments involving section positions that are updated during the SECTIONS parsing. Commitaa69fb62be("arm64/efi: Mark __efistub_stext_offset as an absolute symbol explicitly") ran into this too, but found a different workaround. However, this was not enough, as other variables were also miscalculated which manifested as boot failures under UEFI where __efistub__end was not taking the correct _end value (they should be the same): $ ld.lld -EL -maarch64elf --no-undefined -X -shared \ -Bsymbolic -z notext -z norelro --no-apply-dynamic-relocs \ -o vmlinux.lld -T poc.lds --whole-archive vmlinux.o && \ readelf -Ws vmlinux.lld | egrep '\b(__efistub_|)_end\b' 368272: ffff000002218000 0 NOTYPE LOCAL HIDDEN 38 __efistub__end 368322: ffff000012318000 0 NOTYPE GLOBAL DEFAULT 38 _end $ aarch64-linux-gnu-ld.bfd -EL -maarch64elf --no-undefined -X -shared \ -Bsymbolic -z notext -z norelro --no-apply-dynamic-relocs \ -o vmlinux.bfd -T poc.lds --whole-archive vmlinux.o && \ readelf -Ws vmlinux.bfd | egrep '\b(__efistub_|)_end\b' 338124: ffff000012318000 0 NOTYPE LOCAL DEFAULT ABS __efistub__end 383812: ffff000012318000 0 NOTYPE GLOBAL DEFAULT 15325 _end To work around this, all of the __efistub_-prefixed variable assignments need to be moved after the linker script's SECTIONS entry. As it turns out, this also solves the problem fixed in commitaa69fb62be, so those changes are reverted here. Link: https://github.com/ClangBuiltLinux/linux/issues/634 Link: https://bugs.llvm.org/show_bug.cgi?id=42990 Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Will Deacon <will@kernel.org>
52 lines
1.5 KiB
C
52 lines
1.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Linker script variables to be set after section resolution, as
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* ld.lld does not like variables assigned before SECTIONS is processed.
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*/
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#ifndef __ARM64_KERNEL_IMAGE_VARS_H
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#define __ARM64_KERNEL_IMAGE_VARS_H
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#ifndef LINKER_SCRIPT
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#error This file should only be included in vmlinux.lds.S
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#endif
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#ifdef CONFIG_EFI
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__efistub_stext_offset = stext - _text;
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/*
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* The EFI stub has its own symbol namespace prefixed by __efistub_, to
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* isolate it from the kernel proper. The following symbols are legally
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* accessed by the stub, so provide some aliases to make them accessible.
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* Only include data symbols here, or text symbols of functions that are
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* guaranteed to be safe when executed at another offset than they were
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* linked at. The routines below are all implemented in assembler in a
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* position independent manner
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*/
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__efistub_memcmp = __pi_memcmp;
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__efistub_memchr = __pi_memchr;
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__efistub_memcpy = __pi_memcpy;
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__efistub_memmove = __pi_memmove;
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__efistub_memset = __pi_memset;
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__efistub_strlen = __pi_strlen;
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__efistub_strnlen = __pi_strnlen;
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__efistub_strcmp = __pi_strcmp;
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__efistub_strncmp = __pi_strncmp;
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__efistub_strrchr = __pi_strrchr;
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__efistub___flush_dcache_area = __pi___flush_dcache_area;
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#ifdef CONFIG_KASAN
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__efistub___memcpy = __pi_memcpy;
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__efistub___memmove = __pi_memmove;
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__efistub___memset = __pi_memset;
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#endif
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__efistub__text = _text;
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__efistub__end = _end;
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__efistub__edata = _edata;
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__efistub_screen_info = screen_info;
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#endif
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#endif /* __ARM64_KERNEL_IMAGE_VARS_H */
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