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// SPDX-License-Identifier: GPL-2.0+/* *  Kernel module help for s390. * *  S390 version *    Copyright IBM Corp. 2002, 2003 *    Author(s): Arnd Bergmann (arndb@de.ibm.com) *		 Martin Schwidefsky (schwidefsky@de.ibm.com) * *  based on i386 version *    Copyright (C) 2001 Rusty Russell. */#include <linux/module.h>#include <linux/elf.h>#include <linux/vmalloc.h>#include <linux/fs.h>#include <linux/ftrace.h>#include <linux/string.h>#include <linux/kernel.h>#include <linux/kasan.h>#include <linux/moduleloader.h>#include <linux/bug.h>#include <linux/memory.h>#include <linux/execmem.h>#include <asm/arch-stackprotector.h>#include <asm/alternative.h>#include <asm/nospec-branch.h>#include <asm/facility.h>#include <asm/ftrace.lds.h>#include <asm/set_memory.h>#include <asm/setup.h>#include <asm/asm-offsets.h> #if 0#define DEBUGP printk#else#define DEBUGP(fmt , ...)#endif #define PLT_ENTRY_SIZE 22 #ifdef CONFIG_FUNCTION_TRACERvoid module_arch_cleanup(struct module *mod){	execmem_free(mod->arch.trampolines_start);}#endif void module_arch_freeing_init(struct module *mod){	if (is_livepatch_module(mod) &&	    mod->state == MODULE_STATE_LIVE)		return; 	vfree(mod->arch.syminfo);	mod->arch.syminfo = NULL;} static void check_rela(Elf_Rela *rela, struct module *me){	struct mod_arch_syminfo *info; 	info = me->arch.syminfo + ELF_R_SYM (rela->r_info);	switch (ELF_R_TYPE (rela->r_info)) {	case R_390_GOT12:	/* 12 bit GOT offset.  */	case R_390_GOT16:	/* 16 bit GOT offset.  */	case R_390_GOT20:	/* 20 bit GOT offset.  */	case R_390_GOT32:	/* 32 bit GOT offset.  */	case R_390_GOT64:	/* 64 bit GOT offset.  */	case R_390_GOTENT:	/* 32 bit PC rel. to GOT entry shifted by 1. */	case R_390_GOTPLT12:	/* 12 bit offset to jump slot.	*/	case R_390_GOTPLT16:	/* 16 bit offset to jump slot.  */	case R_390_GOTPLT20:	/* 20 bit offset to jump slot.  */	case R_390_GOTPLT32:	/* 32 bit offset to jump slot.  */	case R_390_GOTPLT64:	/* 64 bit offset to jump slot.	*/	case R_390_GOTPLTENT:	/* 32 bit rel. offset to jump slot >> 1. */		if (info->got_offset == -1UL) {			info->got_offset = me->arch.got_size;			me->arch.got_size += sizeof(void*);		}		break;	case R_390_PLT16DBL:	/* 16 bit PC rel. PLT shifted by 1.  */	case R_390_PLT32DBL:	/* 32 bit PC rel. PLT shifted by 1.  */	case R_390_PLT32:	/* 32 bit PC relative PLT address.  */	case R_390_PLT64:	/* 64 bit PC relative PLT address.  */	case R_390_PLTOFF16:	/* 16 bit offset from GOT to PLT. */	case R_390_PLTOFF32:	/* 32 bit offset from GOT to PLT. */	case R_390_PLTOFF64:	/* 16 bit offset from GOT to PLT. */		if (info->plt_offset == -1UL) {			info->plt_offset = me->arch.plt_size;			me->arch.plt_size += PLT_ENTRY_SIZE;		}		break;	case R_390_COPY:	case R_390_GLOB_DAT:	case R_390_JMP_SLOT:	case R_390_RELATIVE:		/* Only needed if we want to support loading of 		   modules linked with -shared. */		break;	}} /* * Account for GOT and PLT relocations. We can't add sections for * got and plt but we can increase the core module size. */int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,			      char *secstrings, struct module *me){	Elf_Shdr *symtab;	Elf_Sym *symbols;	Elf_Rela *rela;	char *strings;	int nrela, i, j;	struct module_memory *mod_mem; 	/* Find symbol table and string table. */	symtab = NULL;	for (i = 0; i < hdr->e_shnum; i++)		switch (sechdrs[i].sh_type) {		case SHT_SYMTAB:			symtab = sechdrs + i;			break;		}	if (!symtab) {		printk(KERN_ERR "module %s: no symbol table\n", me->name);		return -ENOEXEC;	} 	/* Allocate one syminfo structure per symbol. */	me->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym);	me->arch.syminfo = vmalloc(array_size(sizeof(struct mod_arch_syminfo),					      me->arch.nsyms));	if (!me->arch.syminfo)		return -ENOMEM;	symbols = (void *) hdr + symtab->sh_offset;	strings = (void *) hdr + sechdrs[symtab->sh_link].sh_offset;	for (i = 0; i < me->arch.nsyms; i++) {		if (symbols[i].st_shndx == SHN_UNDEF &&		    strcmp(strings + symbols[i].st_name,			   "_GLOBAL_OFFSET_TABLE_") == 0)			/* "Define" it as absolute. */			symbols[i].st_shndx = SHN_ABS;		me->arch.syminfo[i].got_offset = -1UL;		me->arch.syminfo[i].plt_offset = -1UL;		me->arch.syminfo[i].got_initialized = 0;		me->arch.syminfo[i].plt_initialized = 0;	} 	/* Search for got/plt relocations. */	me->arch.got_size = me->arch.plt_size = 0;	for (i = 0; i < hdr->e_shnum; i++) {		if (sechdrs[i].sh_type != SHT_RELA)			continue;		nrela = sechdrs[i].sh_size / sizeof(Elf_Rela);		rela = (void *) hdr + sechdrs[i].sh_offset;		for (j = 0; j < nrela; j++)			check_rela(rela + j, me);	} 	/* Increase core size by size of got & plt and set start	   offsets for got and plt. */	mod_mem = &me->mem[MOD_TEXT];	mod_mem->size = ALIGN(mod_mem->size, 4);	me->arch.got_offset = mod_mem->size;	mod_mem->size += me->arch.got_size;	me->arch.plt_offset = mod_mem->size;	if (me->arch.plt_size) {		if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_disable)			me->arch.plt_size += PLT_ENTRY_SIZE;		mod_mem->size += me->arch.plt_size;	}	return 0;} static int apply_rela_bits(Elf_Addr loc, Elf_Addr val,			   int sign, int bits, int shift,			   void *(*write)(void *dest, const void *src, size_t len)){	unsigned long umax;	long min, max;	void *dest = (void *)loc; 	if (val & ((1UL << shift) - 1))		return -ENOEXEC;	if (sign) {		val = (Elf_Addr)(((long) val) >> shift);		min = -(1L << (bits - 1));		max = (1L << (bits - 1)) - 1;		if ((long) val < min || (long) val > max)			return -ENOEXEC;	} else {		val >>= shift;		umax = ((1UL << (bits - 1)) << 1) - 1;		if ((unsigned long) val > umax)			return -ENOEXEC;	} 	if (bits == 8) {		unsigned char tmp = val;		write(dest, &tmp, 1);	} else if (bits == 12) {		unsigned short tmp = (val & 0xfff) |			(*(unsigned short *) loc & 0xf000);		write(dest, &tmp, 2);	} else if (bits == 16) {		unsigned short tmp = val;		write(dest, &tmp, 2);	} else if (bits == 20) {		unsigned int tmp = (val & 0xfff) << 16 |			(val & 0xff000) >> 4 | (*(unsigned int *) loc & 0xf00000ff);		write(dest, &tmp, 4);	} else if (bits == 32) {		unsigned int tmp = val;		write(dest, &tmp, 4);	} else if (bits == 64) {		unsigned long tmp = val;		write(dest, &tmp, 8);	}	return 0;} static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,		      const char *strtab, struct module *me,		      void *(*write)(void *dest, const void *src, size_t len)){	struct mod_arch_syminfo *info;	Elf_Addr loc, val;	int r_type, r_sym;	int rc = -ENOEXEC; 	/* This is where to make the change */	loc = base + rela->r_offset;	/* This is the symbol it is referring to.  Note that all	   undefined symbols have been resolved.  */	r_sym = ELF_R_SYM(rela->r_info);	r_type = ELF_R_TYPE(rela->r_info);	info = me->arch.syminfo + r_sym;	val = symtab[r_sym].st_value; 	switch (r_type) {	case R_390_NONE:	/* No relocation.  */		rc = 0;		break;	case R_390_8:		/* Direct 8 bit.   */	case R_390_12:		/* Direct 12 bit.  */	case R_390_16:		/* Direct 16 bit.  */	case R_390_20:		/* Direct 20 bit.  */	case R_390_32:		/* Direct 32 bit.  */	case R_390_64:		/* Direct 64 bit.  */		val += rela->r_addend;		if (r_type == R_390_8)			rc = apply_rela_bits(loc, val, 0, 8, 0, write);		else if (r_type == R_390_12)			rc = apply_rela_bits(loc, val, 0, 12, 0, write);		else if (r_type == R_390_16)			rc = apply_rela_bits(loc, val, 0, 16, 0, write);		else if (r_type == R_390_20)			rc = apply_rela_bits(loc, val, 1, 20, 0, write);		else if (r_type == R_390_32)			rc = apply_rela_bits(loc, val, 0, 32, 0, write);		else if (r_type == R_390_64)			rc = apply_rela_bits(loc, val, 0, 64, 0, write);		break;	case R_390_PC16:	/* PC relative 16 bit.  */	case R_390_PC16DBL:	/* PC relative 16 bit shifted by 1.  */	case R_390_PC32DBL:	/* PC relative 32 bit shifted by 1.  */	case R_390_PC32:	/* PC relative 32 bit.  */	case R_390_PC64:	/* PC relative 64 bit.	*/		val += rela->r_addend - loc;		if (r_type == R_390_PC16)			rc = apply_rela_bits(loc, val, 1, 16, 0, write);		else if (r_type == R_390_PC16DBL)			rc = apply_rela_bits(loc, val, 1, 16, 1, write);		else if (r_type == R_390_PC32DBL)			rc = apply_rela_bits(loc, val, 1, 32, 1, write);		else if (r_type == R_390_PC32)			rc = apply_rela_bits(loc, val, 1, 32, 0, write);		else if (r_type == R_390_PC64)			rc = apply_rela_bits(loc, val, 1, 64, 0, write);		break;	case R_390_GOT12:	/* 12 bit GOT offset.  */	case R_390_GOT16:	/* 16 bit GOT offset.  */	case R_390_GOT20:	/* 20 bit GOT offset.  */	case R_390_GOT32:	/* 32 bit GOT offset.  */	case R_390_GOT64:	/* 64 bit GOT offset.  */	case R_390_GOTENT:	/* 32 bit PC rel. to GOT entry shifted by 1. */	case R_390_GOTPLT12:	/* 12 bit offset to jump slot.	*/	case R_390_GOTPLT20:	/* 20 bit offset to jump slot.  */	case R_390_GOTPLT16:	/* 16 bit offset to jump slot.  */	case R_390_GOTPLT32:	/* 32 bit offset to jump slot.  */	case R_390_GOTPLT64:	/* 64 bit offset to jump slot.	*/	case R_390_GOTPLTENT:	/* 32 bit rel. offset to jump slot >> 1. */		if (info->got_initialized == 0) {			Elf_Addr *gotent = me->mem[MOD_TEXT].base +					   me->arch.got_offset +					   info->got_offset; 			write(gotent, &val, sizeof(*gotent));			info->got_initialized = 1;		}		val = info->got_offset + rela->r_addend;		if (r_type == R_390_GOT12 ||		    r_type == R_390_GOTPLT12)			rc = apply_rela_bits(loc, val, 0, 12, 0, write);		else if (r_type == R_390_GOT16 ||			 r_type == R_390_GOTPLT16)			rc = apply_rela_bits(loc, val, 0, 16, 0, write);		else if (r_type == R_390_GOT20 ||			 r_type == R_390_GOTPLT20)			rc = apply_rela_bits(loc, val, 1, 20, 0, write);		else if (r_type == R_390_GOT32 ||			 r_type == R_390_GOTPLT32)			rc = apply_rela_bits(loc, val, 0, 32, 0, write);		else if (r_type == R_390_GOT64 ||			 r_type == R_390_GOTPLT64)			rc = apply_rela_bits(loc, val, 0, 64, 0, write);		else if (r_type == R_390_GOTENT ||			 r_type == R_390_GOTPLTENT) {			val += (Elf_Addr)me->mem[MOD_TEXT].base +				me->arch.got_offset - loc;			rc = apply_rela_bits(loc, val, 1, 32, 1, write);		}		break;	case R_390_PLT16DBL:	/* 16 bit PC rel. PLT shifted by 1.  */	case R_390_PLT32DBL:	/* 32 bit PC rel. PLT shifted by 1.  */	case R_390_PLT32:	/* 32 bit PC relative PLT address.  */	case R_390_PLT64:	/* 64 bit PC relative PLT address.  */	case R_390_PLTOFF16:	/* 16 bit offset from GOT to PLT. */	case R_390_PLTOFF32:	/* 32 bit offset from GOT to PLT. */	case R_390_PLTOFF64:	/* 16 bit offset from GOT to PLT. */		if (info->plt_initialized == 0) {			unsigned char insn[PLT_ENTRY_SIZE];			char *plt_base;			char *ip; 			plt_base = me->mem[MOD_TEXT].base + me->arch.plt_offset;			ip = plt_base + info->plt_offset;			*(int *)insn = 0x0d10e310;	/* basr 1,0  */			*(int *)&insn[4] = 0x100c0004;	/* lg	1,12(1) */			if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_disable) {				char *jump_r1; 				jump_r1 = plt_base + me->arch.plt_size -					PLT_ENTRY_SIZE;				/* brcl	0xf,__jump_r1 */				*(short *)&insn[8] = 0xc0f4;				*(int *)&insn[10] = (jump_r1 - (ip + 8)) / 2;			} else {				*(int *)&insn[8] = 0x07f10000;	/* br %r1 */			}			*(long *)&insn[14] = val; 			write(ip, insn, sizeof(insn));			info->plt_initialized = 1;		}		if (r_type == R_390_PLTOFF16 ||		    r_type == R_390_PLTOFF32 ||		    r_type == R_390_PLTOFF64)			val = me->arch.plt_offset - me->arch.got_offset +				info->plt_offset + rela->r_addend;		else {			if (!((r_type == R_390_PLT16DBL &&			       val - loc + 0xffffUL < 0x1ffffeUL) ||			      (r_type == R_390_PLT32DBL &&			       val - loc + 0xffffffffULL < 0x1fffffffeULL)))				val = (Elf_Addr) me->mem[MOD_TEXT].base +					me->arch.plt_offset +					info->plt_offset;			val += rela->r_addend - loc;		}		if (r_type == R_390_PLT16DBL)			rc = apply_rela_bits(loc, val, 1, 16, 1, write);		else if (r_type == R_390_PLTOFF16)			rc = apply_rela_bits(loc, val, 0, 16, 0, write);		else if (r_type == R_390_PLT32DBL)			rc = apply_rela_bits(loc, val, 1, 32, 1, write);		else if (r_type == R_390_PLT32 ||			 r_type == R_390_PLTOFF32)			rc = apply_rela_bits(loc, val, 0, 32, 0, write);		else if (r_type == R_390_PLT64 ||			 r_type == R_390_PLTOFF64)			rc = apply_rela_bits(loc, val, 0, 64, 0, write);		break;	case R_390_GOTOFF16:	/* 16 bit offset to GOT.  */	case R_390_GOTOFF32:	/* 32 bit offset to GOT.  */	case R_390_GOTOFF64:	/* 64 bit offset to GOT. */		val = val + rela->r_addend -			((Elf_Addr) me->mem[MOD_TEXT].base + me->arch.got_offset);		if (r_type == R_390_GOTOFF16)			rc = apply_rela_bits(loc, val, 0, 16, 0, write);		else if (r_type == R_390_GOTOFF32)			rc = apply_rela_bits(loc, val, 0, 32, 0, write);		else if (r_type == R_390_GOTOFF64)			rc = apply_rela_bits(loc, val, 0, 64, 0, write);		break;	case R_390_GOTPC:	/* 32 bit PC relative offset to GOT. */	case R_390_GOTPCDBL:	/* 32 bit PC rel. off. to GOT shifted by 1. */		val = (Elf_Addr) me->mem[MOD_TEXT].base + me->arch.got_offset +			rela->r_addend - loc;		if (r_type == R_390_GOTPC)			rc = apply_rela_bits(loc, val, 1, 32, 0, write);		else if (r_type == R_390_GOTPCDBL)			rc = apply_rela_bits(loc, val, 1, 32, 1, write);		break;	case R_390_COPY:	case R_390_GLOB_DAT:	/* Create GOT entry.  */	case R_390_JMP_SLOT:	/* Create PLT entry.  */	case R_390_RELATIVE:	/* Adjust by program base.  */		/* Only needed if we want to support loading of 		   modules linked with -shared. */		return -ENOEXEC;	default:		printk(KERN_ERR "module %s: unknown relocation: %u\n",		       me->name, r_type);		return -ENOEXEC;	}	if (rc) {		printk(KERN_ERR "module %s: relocation error for symbol %s "		       "(r_type %i, value 0x%lx)\n",		       me->name, strtab + symtab[r_sym].st_name,		       r_type, (unsigned long) val);		return rc;	}	return 0;} static int __apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,		       unsigned int symindex, unsigned int relsec,		       struct module *me,		       void *(*write)(void *dest, const void *src, size_t len)){	Elf_Addr base;	Elf_Sym *symtab;	Elf_Rela *rela;	unsigned long i, n;	int rc; 	DEBUGP("Applying relocate section %u to %u\n",	       relsec, sechdrs[relsec].sh_info);	base = sechdrs[sechdrs[relsec].sh_info].sh_addr;	symtab = (Elf_Sym *) sechdrs[symindex].sh_addr;	rela = (Elf_Rela *) sechdrs[relsec].sh_addr;	n = sechdrs[relsec].sh_size / sizeof(Elf_Rela); 	for (i = 0; i < n; i++, rela++) {		rc = apply_rela(rela, base, symtab, strtab, me, write);		if (rc)			return rc;	}	return 0;} int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,		       unsigned int symindex, unsigned int relsec,		       struct module *me){	bool early = me->state == MODULE_STATE_UNFORMED;	void *(*write)(void *, const void *, size_t) = memcpy; 	if (!early)		write = s390_kernel_write; 	return __apply_relocate_add(sechdrs, strtab, symindex, relsec, me,				    write);} #ifdef CONFIG_FUNCTION_TRACERstatic int module_alloc_ftrace_hotpatch_trampolines(struct module *me,						    const Elf_Shdr *s){	char *start, *end;	int numpages;	size_t size; 	size = FTRACE_HOTPATCH_TRAMPOLINES_SIZE(s->sh_size);	numpages = DIV_ROUND_UP(size, PAGE_SIZE);	start = execmem_alloc(EXECMEM_FTRACE, numpages * PAGE_SIZE);	if (!start)		return -ENOMEM;	set_memory_rox((unsigned long)start, numpages);	end = start + size; 	me->arch.trampolines_start = (struct ftrace_hotpatch_trampoline *)start;	me->arch.trampolines_end = (struct ftrace_hotpatch_trampoline *)end;	me->arch.next_trampoline = me->arch.trampolines_start; 	return 0;}#endif /* CONFIG_FUNCTION_TRACER */ int module_finalize(const Elf_Ehdr *hdr,		    const Elf_Shdr *sechdrs,		    struct module *me){	const Elf_Shdr *s;	char *secstrings, *secname;	void *aseg;	int rc = 0;

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