34ab1a1e51
Currently LLEXT on Xtensa supports relocatable extensions, linked for a specific address range, while relocation itself takes place in a temporary buffer. For this section addresses have to be set correctly by the linker for their target locations. This commit adds support for relocatable extensions, built without using specific memory addresses and run at the same addresses, where they are loaded. Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
61 lines
1.7 KiB
C
61 lines
1.7 KiB
C
/*
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* Copyright (c) 2023 Intel Corporation
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <zephyr/llext/elf.h>
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#include <zephyr/llext/llext.h>
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#include <zephyr/llext/loader.h>
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#include <zephyr/logging/log.h>
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LOG_MODULE_DECLARE(llext);
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#define R_XTENSA_NONE 0
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#define R_XTENSA_32 1
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#define R_XTENSA_RTLD 2
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#define R_XTENSA_GLOB_DAT 3
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#define R_XTENSA_JMP_SLOT 4
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#define R_XTENSA_RELATIVE 5
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#define R_XTENSA_PLT 6
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/**
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* @brief Architecture specific function for relocating shared elf
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*
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* Elf files contain a series of relocations described in multiple sections.
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* These relocation instructions are architecture specific and each architecture
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* supporting modules must implement this.
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*/
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void arch_elf_relocate_local(struct llext_loader *ldr, struct llext *ext,
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const elf_rela_t *rel, const elf_sym_t *sym, size_t got_offset)
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{
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uint8_t *text = ext->mem[LLEXT_MEM_TEXT];
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int type = ELF32_R_TYPE(rel->r_info);
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elf_word *got_entry = (elf_word *)(text + got_offset);
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uintptr_t sh_addr;
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if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) {
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elf_shdr_t *shdr = llext_peek(ldr, ldr->hdr.e_shoff +
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sym->st_shndx * ldr->hdr.e_shentsize);
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sh_addr = shdr->sh_addr ? : (uintptr_t)llext_peek(ldr, shdr->sh_offset);
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} else {
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sh_addr = ldr->sects[LLEXT_MEM_TEXT].sh_addr;
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}
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switch (type) {
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case R_XTENSA_RELATIVE:
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/* Relocate a local symbol: Xtensa specific */
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*got_entry += (uintptr_t)text - sh_addr;
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break;
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case R_XTENSA_32:
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*got_entry += sh_addr;
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break;
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default:
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LOG_DBG("unsupported relocation type %u", type);
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return;
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}
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LOG_DBG("relocation to %#x type %u at %p", *got_entry, type, (void *)got_entry);
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}
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