// SPDX-License-Identifier: GPL-2.0-only/* * Kernel module loader for Hexagon * * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved. */ #include <asm/module.h>#include <linux/elf.h>#include <linux/module.h>#include <linux/moduleloader.h>#include <linux/vmalloc.h> #if 0#define DEBUGP printk#else#define DEBUGP(fmt , ...)#endif /* * module_frob_arch_sections - tweak got/plt sections. * @hdr - pointer to elf header * @sechdrs - pointer to elf load section headers * @secstrings - symbol names * @mod - pointer to module */int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,				char *secstrings,				struct module *mod){	unsigned int i;	int found = 0; 	/* Look for .plt and/or .got.plt and/or .init.plt sections */	for (i = 0; i < hdr->e_shnum; i++) {		DEBUGP("Section %d is %s\n", i,		       secstrings + sechdrs[i].sh_name);		if (strcmp(secstrings + sechdrs[i].sh_name, ".plt") == 0)			found = i+1;		if (strcmp(secstrings + sechdrs[i].sh_name, ".got.plt") == 0)			found = i+1;		if (strcmp(secstrings + sechdrs[i].sh_name, ".rela.plt") == 0)			found = i+1;	} 	/* At this time, we don't support modules comiled with -shared */	if (found) {		printk(KERN_WARNING			"Module '%s' contains unexpected .plt/.got sections.\n",			mod->name);		/*  return -ENOEXEC;  */	} 	return 0;} /* * apply_relocate_add - perform rela relocations. * @sechdrs - pointer to section headers * @strtab - some sort of start address? * @symindex - symbol index offset or something? * @relsec - address to relocate to? * @module - pointer to module * * Perform rela relocations. */int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,			unsigned int symindex, unsigned int relsec,			struct module *module){	unsigned int i;	Elf32_Sym *sym;	uint32_t *location;	uint32_t value;	unsigned int nrelocs = sechdrs[relsec].sh_size / sizeof(Elf32_Rela);	Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;	Elf32_Word sym_info = sechdrs[relsec].sh_info;	Elf32_Sym *sym_base = (Elf32_Sym *) sechdrs[symindex].sh_addr;	void *loc_base = (void *) sechdrs[sym_info].sh_addr; 	DEBUGP("Applying relocations in section %u to section %u base=%p\n",	       relsec, sym_info, loc_base); 	for (i = 0; i < nrelocs; i++) { 		/* Symbol to relocate */		sym = sym_base + ELF32_R_SYM(rela[i].r_info); 		/* Where to make the change */		location = loc_base + rela[i].r_offset; 		/* `Everything is relative'. */		value = sym->st_value + rela[i].r_addend; 		DEBUGP("%d: value=%08x loc=%p reloc=%d symbol=%s\n",		       i, value, location, ELF32_R_TYPE(rela[i].r_info),		       sym->st_name ?		       &strtab[sym->st_name] : "(anonymous)"); 		switch (ELF32_R_TYPE(rela[i].r_info)) {		case R_HEXAGON_B22_PCREL: {			int dist = (int)(value - (uint32_t)location);			if ((dist < -0x00800000) ||			    (dist >= 0x00800000)) {				printk(KERN_ERR				       "%s: %s: %08x=%08x-%08x %s\n",				       module->name,				       "R_HEXAGON_B22_PCREL reloc out of range",				       dist, value, (uint32_t)location,				       sym->st_name ?				       &strtab[sym->st_name] : "(anonymous)");				return -ENOEXEC;			}			DEBUGP("B22_PCREL contents: %08X.\n", *location);			*location &= ~0x01ff3fff;			*location |= 0x00003fff & dist;			*location |= 0x01ff0000 & (dist<<2);			DEBUGP("Contents after reloc: %08x\n", *location);			break;		}		case R_HEXAGON_HI16:			value = (value>>16) & 0xffff;			fallthrough;		case R_HEXAGON_LO16:			*location &= ~0x00c03fff;			*location |= value & 0x3fff;			*location |= (value & 0xc000) << 8;			break;		case R_HEXAGON_32:			*location = value;			break;		case R_HEXAGON_32_PCREL:			*location = value - (uint32_t)location;			break;		case R_HEXAGON_PLT_B22_PCREL:		case R_HEXAGON_GOTOFF_LO16:		case R_HEXAGON_GOTOFF_HI16:			printk(KERN_ERR "%s: GOT/PLT relocations unsupported\n",			       module->name);			return -ENOEXEC;		default:			printk(KERN_ERR "%s: unknown relocation: %u\n",			       module->name,			       ELF32_R_TYPE(rela[i].r_info));			return -ENOEXEC;		}	}	return 0;}