147 строки
4.2 KiB
C
147 строки
4.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
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*/
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#include <linux/module.h>
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#include <linux/moduleloader.h>
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#include <linux/kernel.h>
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#include <linux/elf.h>
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#include <linux/vmalloc.h>
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#include <linux/slab.h>
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#include <linux/fs.h>
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#include <linux/string.h>
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#include <asm/unwind.h>
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static inline void arc_write_me(unsigned short *addr, unsigned long value)
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{
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*addr = (value & 0xffff0000) >> 16;
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*(addr + 1) = (value & 0xffff);
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}
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/*
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* This gets called before relocation loop in generic loader
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* Make a note of the section index of unwinding section
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*/
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int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
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char *secstr, struct module *mod)
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{
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#ifdef CONFIG_ARC_DW2_UNWIND
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mod->arch.unw_sec_idx = 0;
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mod->arch.unw_info = NULL;
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#endif
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mod->arch.secstr = secstr;
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return 0;
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}
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void module_arch_cleanup(struct module *mod)
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{
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#ifdef CONFIG_ARC_DW2_UNWIND
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if (mod->arch.unw_info)
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unwind_remove_table(mod->arch.unw_info, 0);
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#endif
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}
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int apply_relocate_add(Elf32_Shdr *sechdrs,
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const char *strtab,
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unsigned int symindex, /* sec index for sym tbl */
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unsigned int relsec, /* sec index for relo sec */
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struct module *module)
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{
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int i, n, relo_type;
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Elf32_Rela *rel_entry = (void *)sechdrs[relsec].sh_addr;
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Elf32_Sym *sym_entry, *sym_sec;
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Elf32_Addr relocation, location, tgt_addr;
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unsigned int tgtsec;
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/*
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* @relsec has relocations e.g. .rela.init.text
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* @tgtsec is section to patch e.g. .init.text
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*/
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tgtsec = sechdrs[relsec].sh_info;
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tgt_addr = sechdrs[tgtsec].sh_addr;
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sym_sec = (Elf32_Sym *) sechdrs[symindex].sh_addr;
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n = sechdrs[relsec].sh_size / sizeof(*rel_entry);
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pr_debug("\nSection to fixup %s @%x\n",
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module->arch.secstr + sechdrs[tgtsec].sh_name, tgt_addr);
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pr_debug("=========================================================\n");
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pr_debug("r_off\tr_add\tst_value ADDRESS VALUE\n");
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pr_debug("=========================================================\n");
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/* Loop thru entries in relocation section */
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for (i = 0; i < n; i++) {
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const char *s;
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/* This is where to make the change */
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location = tgt_addr + rel_entry[i].r_offset;
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/* This is the symbol it is referring to. Note that all
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undefined symbols have been resolved. */
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sym_entry = sym_sec + ELF32_R_SYM(rel_entry[i].r_info);
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relocation = sym_entry->st_value + rel_entry[i].r_addend;
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if (sym_entry->st_name == 0 && ELF_ST_TYPE (sym_entry->st_info) == STT_SECTION) {
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s = module->arch.secstr + sechdrs[sym_entry->st_shndx].sh_name;
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} else {
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s = strtab + sym_entry->st_name;
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}
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pr_debug(" %x\t%x\t%x %x %x [%s]\n",
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rel_entry[i].r_offset, rel_entry[i].r_addend,
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sym_entry->st_value, location, relocation, s);
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/* This assumes modules are built with -mlong-calls
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* so any branches/jumps are absolute 32 bit jmps
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* global data access again is abs 32 bit.
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* Both of these are handled by same relocation type
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*/
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relo_type = ELF32_R_TYPE(rel_entry[i].r_info);
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if (likely(R_ARC_32_ME == relo_type)) /* ME ( S + A ) */
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arc_write_me((unsigned short *)location, relocation);
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else if (R_ARC_32 == relo_type) /* ( S + A ) */
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*((Elf32_Addr *) location) = relocation;
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else if (R_ARC_32_PCREL == relo_type) /* ( S + A ) - PDATA ) */
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*((Elf32_Addr *) location) = relocation - location;
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else
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goto relo_err;
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}
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#ifdef CONFIG_ARC_DW2_UNWIND
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if (strcmp(module->arch.secstr+sechdrs[tgtsec].sh_name, ".eh_frame") == 0)
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module->arch.unw_sec_idx = tgtsec;
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#endif
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return 0;
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relo_err:
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pr_err("%s: unknown relocation: %u\n",
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module->name, ELF32_R_TYPE(rel_entry[i].r_info));
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return -ENOEXEC;
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}
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/* Just before lift off: After sections have been relocated, we add the
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* dwarf section to unwinder table pool
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* This couldn't be done in module_frob_arch_sections() because
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* relocations had not been applied by then
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*/
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int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
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struct module *mod)
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{
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#ifdef CONFIG_ARC_DW2_UNWIND
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void *unw;
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int unwsec = mod->arch.unw_sec_idx;
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if (unwsec) {
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unw = unwind_add_table(mod, (void *)sechdrs[unwsec].sh_addr,
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sechdrs[unwsec].sh_size);
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mod->arch.unw_info = unw;
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}
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#endif
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return 0;
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}
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