diff options
Diffstat (limited to 'arch/arc/kernel/module.c')
| -rw-r--r-- | arch/arc/kernel/module.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/arch/arc/kernel/module.c b/arch/arc/kernel/module.c new file mode 100644 index 0000000000..c90c279047 --- /dev/null +++ b/arch/arc/kernel/module.c @@ -0,0 +1,146 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) + */ + +#include <linux/module.h> +#include <linux/moduleloader.h> +#include <linux/kernel.h> +#include <linux/elf.h> +#include <linux/vmalloc.h> +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/string.h> +#include <asm/unwind.h> + +static inline void arc_write_me(unsigned short *addr, unsigned long value) +{ + *addr = (value & 0xffff0000) >> 16; + *(addr + 1) = (value & 0xffff); +} + +/* + * This gets called before relocation loop in generic loader + * Make a note of the section index of unwinding section + */ +int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, + char *secstr, struct module *mod) +{ +#ifdef CONFIG_ARC_DW2_UNWIND + mod->arch.unw_sec_idx = 0; + mod->arch.unw_info = NULL; +#endif + mod->arch.secstr = secstr; + return 0; +} + +void module_arch_cleanup(struct module *mod) +{ +#ifdef CONFIG_ARC_DW2_UNWIND + if (mod->arch.unw_info) + unwind_remove_table(mod->arch.unw_info, 0); +#endif +} + +int apply_relocate_add(Elf32_Shdr *sechdrs, + const char *strtab, + unsigned int symindex, /* sec index for sym tbl */ + unsigned int relsec, /* sec index for relo sec */ + struct module *module) +{ + int i, n, relo_type; + Elf32_Rela *rel_entry = (void *)sechdrs[relsec].sh_addr; + Elf32_Sym *sym_entry, *sym_sec; + Elf32_Addr relocation, location, tgt_addr; + unsigned int tgtsec; + + /* + * @relsec has relocations e.g. .rela.init.text + * @tgtsec is section to patch e.g. .init.text + */ + tgtsec = sechdrs[relsec].sh_info; + tgt_addr = sechdrs[tgtsec].sh_addr; + sym_sec = (Elf32_Sym *) sechdrs[symindex].sh_addr; + n = sechdrs[relsec].sh_size / sizeof(*rel_entry); + + pr_debug("\nSection to fixup %s @%x\n", + module->arch.secstr + sechdrs[tgtsec].sh_name, tgt_addr); + pr_debug("=========================================================\n"); + pr_debug("r_off\tr_add\tst_value ADDRESS VALUE\n"); + pr_debug("=========================================================\n"); + + /* Loop thru entries in relocation section */ + for (i = 0; i < n; i++) { + const char *s; + + /* This is where to make the change */ + location = tgt_addr + rel_entry[i].r_offset; + + /* This is the symbol it is referring to. Note that all + undefined symbols have been resolved. */ + sym_entry = sym_sec + ELF32_R_SYM(rel_entry[i].r_info); + + relocation = sym_entry->st_value + rel_entry[i].r_addend; + + if (sym_entry->st_name == 0 && ELF_ST_TYPE (sym_entry->st_info) == STT_SECTION) { + s = module->arch.secstr + sechdrs[sym_entry->st_shndx].sh_name; + } else { + s = strtab + sym_entry->st_name; + } + + pr_debug(" %x\t%x\t%x %x %x [%s]\n", + rel_entry[i].r_offset, rel_entry[i].r_addend, + sym_entry->st_value, location, relocation, s); + + /* This assumes modules are built with -mlong-calls + * so any branches/jumps are absolute 32 bit jmps + * global data access again is abs 32 bit. + * Both of these are handled by same relocation type + */ + relo_type = ELF32_R_TYPE(rel_entry[i].r_info); + + if (likely(R_ARC_32_ME == relo_type)) /* ME ( S + A ) */ + arc_write_me((unsigned short *)location, relocation); + else if (R_ARC_32 == relo_type) /* ( S + A ) */ + *((Elf32_Addr *) location) = relocation; + else if (R_ARC_32_PCREL == relo_type) /* ( S + A ) - PDATA ) */ + *((Elf32_Addr *) location) = relocation - location; + else + goto relo_err; + + } + +#ifdef CONFIG_ARC_DW2_UNWIND + if (strcmp(module->arch.secstr+sechdrs[tgtsec].sh_name, ".eh_frame") == 0) + module->arch.unw_sec_idx = tgtsec; +#endif + + return 0; + +relo_err: + pr_err("%s: unknown relocation: %u\n", + module->name, ELF32_R_TYPE(rel_entry[i].r_info)); + return -ENOEXEC; + +} + +/* Just before lift off: After sections have been relocated, we add the + * dwarf section to unwinder table pool + * This couldn't be done in module_frob_arch_sections() because + * relocations had not been applied by then + */ +int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs, + struct module *mod) +{ +#ifdef CONFIG_ARC_DW2_UNWIND + void *unw; + int unwsec = mod->arch.unw_sec_idx; + + if (unwsec) { + unw = unwind_add_table(mod, (void *)sechdrs[unwsec].sh_addr, + sechdrs[unwsec].sh_size); + mod->arch.unw_info = unw; + } +#endif + return 0; +} |