[mirror_ubuntu-eoan-kernel.git] / arch / s390 / kernel / module.c

// 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/string.h>
#include <linux/kernel.h>
#include <linux/moduleloader.h>
#include <linux/bug.h>
#include <asm/alternative.h>
#include <asm/nospec-branch.h>
#include <asm/facility.h>

#if 0
#define DEBUGP printk
#else
#define DEBUGP(fmt , ...)
#endif

#define PLT_ENTRY_SIZE 20

void *module_alloc(unsigned long size)
{
	if (PAGE_ALIGN(size) > MODULES_LEN)
		return NULL;
	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
				    GFP_KERNEL, PAGE_KERNEL_EXEC,
				    0, NUMA_NO_NODE,
				    __builtin_return_address(0));
}

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;

	/* 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. */
	me->core_layout.size = ALIGN(me->core_layout.size, 4);
	me->arch.got_offset = me->core_layout.size;
	me->core_layout.size += me->arch.got_size;
	me->arch.plt_offset = me->core_layout.size;
	if (me->arch.plt_size) {
		if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_disable)
			me->arch.plt_size += PLT_ENTRY_SIZE;
		me->core_layout.size += me->arch.plt_size;
	}
	return 0;
}

static int apply_rela_bits(Elf_Addr loc, Elf_Addr val,
			   int sign, int bits, int shift)
{
	unsigned long umax;
	long min, max;

	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 *) loc = val;
	else if (bits == 12)
		*(unsigned short *) loc = (val & 0xfff) |
			(*(unsigned short *) loc & 0xf000);
	else if (bits == 16)
		*(unsigned short *) loc = val;
	else if (bits == 20)
		*(unsigned int *) loc = (val & 0xfff) << 16 |
			(val & 0xff000) >> 4 |
			(*(unsigned int *) loc & 0xf00000ff);
	else if (bits == 32)
		*(unsigned int *) loc = val;
	else if (bits == 64)
		*(unsigned long *) loc = val;
	return 0;
}

static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
		      const char *strtab, struct module *me)
{
	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);
		else if (r_type == R_390_12)
			rc = apply_rela_bits(loc, val, 0, 12, 0);
		else if (r_type == R_390_16)
			rc = apply_rela_bits(loc, val, 0, 16, 0);
		else if (r_type == R_390_20)
			rc = apply_rela_bits(loc, val, 1, 20, 0);
		else if (r_type == R_390_32)
			rc = apply_rela_bits(loc, val, 0, 32, 0);
		else if (r_type == R_390_64)
			rc = apply_rela_bits(loc, val, 0, 64, 0);
		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);
		else if (r_type == R_390_PC16DBL)
			rc = apply_rela_bits(loc, val, 1, 16, 1);
		else if (r_type == R_390_PC32DBL)
			rc = apply_rela_bits(loc, val, 1, 32, 1);
		else if (r_type == R_390_PC32)
			rc = apply_rela_bits(loc, val, 1, 32, 0);
		else if (r_type == R_390_PC64)
			rc = apply_rela_bits(loc, val, 1, 64, 0);
		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;

			gotent = me->core_layout.base + me->arch.got_offset +
				info->got_offset;
			*gotent = val;
			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);
		else if (r_type == R_390_GOT16 ||
			 r_type == R_390_GOTPLT16)
			rc = apply_rela_bits(loc, val, 0, 16, 0);
		else if (r_type == R_390_GOT20 ||
			 r_type == R_390_GOTPLT20)
			rc = apply_rela_bits(loc, val, 1, 20, 0);
		else if (r_type == R_390_GOT32 ||
			 r_type == R_390_GOTPLT32)
			rc = apply_rela_bits(loc, val, 0, 32, 0);
		else if (r_type == R_390_GOT64 ||
			 r_type == R_390_GOTPLT64)
			rc = apply_rela_bits(loc, val, 0, 64, 0);
		else if (r_type == R_390_GOTENT ||
			 r_type == R_390_GOTPLTENT) {
			val += (Elf_Addr) me->core_layout.base - loc;
			rc = apply_rela_bits(loc, val, 1, 32, 1);
		}
		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 int *ip;
			ip = me->core_layout.base + me->arch.plt_offset +
				info->plt_offset;
			ip[0] = 0x0d10e310;	/* basr 1,0  */
			ip[1] = 0x100a0004;	/* lg	1,10(1) */
			if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_disable) {
				unsigned int *ij;
				ij = me->core_layout.base +
					me->arch.plt_offset +
					me->arch.plt_size - PLT_ENTRY_SIZE;
				ip[2] = 0xa7f40000 +	/* j __jump_r1 */
					(unsigned int)(u16)
					(((unsigned long) ij - 8 -
					  (unsigned long) ip) / 2);
			} else {
				ip[2] = 0x07f10000;	/* br %r1 */
			}
			ip[3] = (unsigned int) (val >> 32);
			ip[4] = (unsigned int) val;
			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->core_layout.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);
		else if (r_type == R_390_PLTOFF16)
			rc = apply_rela_bits(loc, val, 0, 16, 0);
		else if (r_type == R_390_PLT32DBL)
			rc = apply_rela_bits(loc, val, 1, 32, 1);
		else if (r_type == R_390_PLT32 ||
			 r_type == R_390_PLTOFF32)
			rc = apply_rela_bits(loc, val, 0, 32, 0);
		else if (r_type == R_390_PLT64 ||
			 r_type == R_390_PLTOFF64)
			rc = apply_rela_bits(loc, val, 0, 64, 0);
		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->core_layout.base + me->arch.got_offset);
		if (r_type == R_390_GOTOFF16)
			rc = apply_rela_bits(loc, val, 0, 16, 0);
		else if (r_type == R_390_GOTOFF32)
			rc = apply_rela_bits(loc, val, 0, 32, 0);
		else if (r_type == R_390_GOTOFF64)
			rc = apply_rela_bits(loc, val, 0, 64, 0);
		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->core_layout.base + me->arch.got_offset +
			rela->r_addend - loc;
		if (r_type == R_390_GOTPC)
			rc = apply_rela_bits(loc, val, 1, 32, 0);
		else if (r_type == R_390_GOTPCDBL)
			rc = apply_rela_bits(loc, val, 1, 32, 1);
		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;
}

int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
		       unsigned int symindex, unsigned int relsec,
		       struct module *me)
{
	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);
		if (rc)
			return rc;
	}
	return 0;
}

int module_finalize(const Elf_Ehdr *hdr,
		    const Elf_Shdr *sechdrs,
		    struct module *me)
{
	const Elf_Shdr *s;
	char *secstrings, *secname;
	void *aseg;

	if (IS_ENABLED(CONFIG_EXPOLINE) &&
	    !nospec_disable && me->arch.plt_size) {
		unsigned int *ij;

		ij = me->core_layout.base + me->arch.plt_offset +
			me->arch.plt_size - PLT_ENTRY_SIZE;
		if (test_facility(35)) {
			ij[0] = 0xc6000000;	/* exrl	%r0,.+10	*/
			ij[1] = 0x0005a7f4;	/* j	.		*/
			ij[2] = 0x000007f1;	/* br	%r1		*/
		} else {
			ij[0] = 0x44000000 | (unsigned int)
				offsetof(struct lowcore, br_r1_trampoline);
			ij[1] = 0xa7f40000;	/* j	.		*/
		}
	}

	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
		aseg = (void *) s->sh_addr;
		secname = secstrings + s->sh_name;

		if (!strcmp(".altinstructions", secname))
			/* patch .altinstructions */
			apply_alternatives(aseg, aseg + s->sh_size);

		if (IS_ENABLED(CONFIG_EXPOLINE) &&
		    (!strncmp(".s390_indirect", secname, 14)))
			nospec_revert(aseg, aseg + s->sh_size);

		if (IS_ENABLED(CONFIG_EXPOLINE) &&
		    (!strncmp(".s390_return", secname, 12)))
			nospec_revert(aseg, aseg + s->sh_size);
	}

	jump_label_apply_nops(me);
	return 0;
}
Commit	Line	Data
a17ae4c3	1	// SPDX-License-Identifier: GPL-2.0+
1da177e4	2	/*
a53c8fab	3	* Kernel module help for s390.
1da177e4 LT	4	*
1da177e4 LT	5	* S390 version
a53c8fab	6	* Copyright IBM Corp. 2002, 2003
1da177e4 LT	7	* Author(s): Arnd Bergmann (arndb@de.ibm.com)
	8	* Martin Schwidefsky (schwidefsky@de.ibm.com)
	9	*
	10	* based on i386 version
	11	* Copyright (C) 2001 Rusty Russell.
1da177e4 LT	12	*/
	13	#include <linux/module.h>
	14	#include <linux/elf.h>
	15	#include <linux/vmalloc.h>
	16	#include <linux/fs.h>
	17	#include <linux/string.h>
	18	#include <linux/kernel.h>
2b67fc46	19	#include <linux/moduleloader.h>
c0007f1a	20	#include <linux/bug.h>
686140a1	21	#include <asm/alternative.h>
f19fbd5e MS	22	#include <asm/nospec-branch.h>
f19fbd5e MS	23	#include <asm/facility.h>
1da177e4 LT	24
	25	#if 0
	26	#define DEBUGP printk
	27	#else
	28	#define DEBUGP(fmt , ...)
	29	#endif
	30
1da177e4	31	#define PLT_ENTRY_SIZE 20
1da177e4	32
c972cc60 HC	33	void *module_alloc(unsigned long size)
	34	{
	35	if (PAGE_ALIGN(size) > MODULES_LEN)
	36	return NULL;
	37	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
57d7f939 MS	38	GFP_KERNEL, PAGE_KERNEL_EXEC,
57d7f939 MS	39	0, NUMA_NO_NODE,
c972cc60 HC	40	__builtin_return_address(0));
c972cc60 HC	41	}
c972cc60	42
d453cded	43	void module_arch_freeing_init(struct module *mod)
1da177e4	44	{
f31e0960 JY	45	if (is_livepatch_module(mod) &&
	46	mod->state == MODULE_STATE_LIVE)
	47	return;
	48
d453cded RR	49	vfree(mod->arch.syminfo);
d453cded RR	50	mod->arch.syminfo = NULL;
1da177e4 LT	51	}
1da177e4 LT	52
083e14c0	53	static void check_rela(Elf_Rela rela, struct module me)
1da177e4 LT	54	{
	55	struct mod_arch_syminfo *info;
	56
	57	info = me->arch.syminfo + ELF_R_SYM (rela->r_info);
	58	switch (ELF_R_TYPE (rela->r_info)) {
	59	case R_390_GOT12: /* 12 bit GOT offset. */
	60	case R_390_GOT16: /* 16 bit GOT offset. */
	61	case R_390_GOT20: /* 20 bit GOT offset. */
	62	case R_390_GOT32: /* 32 bit GOT offset. */
	63	case R_390_GOT64: /* 64 bit GOT offset. */
	64	case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */
	65	case R_390_GOTPLT12: /* 12 bit offset to jump slot. */
	66	case R_390_GOTPLT16: /* 16 bit offset to jump slot. */
	67	case R_390_GOTPLT20: /* 20 bit offset to jump slot. */
	68	case R_390_GOTPLT32: /* 32 bit offset to jump slot. */
	69	case R_390_GOTPLT64: /* 64 bit offset to jump slot. */
	70	case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */
	71	if (info->got_offset == -1UL) {
	72	info->got_offset = me->arch.got_size;
	73	me->arch.got_size += sizeof(void*);
	74	}
	75	break;
	76	case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */
	77	case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */
	78	case R_390_PLT32: /* 32 bit PC relative PLT address. */
	79	case R_390_PLT64: /* 64 bit PC relative PLT address. */
	80	case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */
	81	case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */
	82	case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */
	83	if (info->plt_offset == -1UL) {
	84	info->plt_offset = me->arch.plt_size;
	85	me->arch.plt_size += PLT_ENTRY_SIZE;
	86	}
	87	break;
	88	case R_390_COPY:
	89	case R_390_GLOB_DAT:
	90	case R_390_JMP_SLOT:
	91	case R_390_RELATIVE:
	92	/* Only needed if we want to support loading of
	93	modules linked with -shared. */
	94	break;
	95	}
	96	}
	97
	98	/*
	99	* Account for GOT and PLT relocations. We can't add sections for
	100	* got and plt but we can increase the core module size.
	101	*/
083e14c0 MS	102	int module_frob_arch_sections(Elf_Ehdr hdr, Elf_Shdr sechdrs,
083e14c0 MS	103	char secstrings, struct module me)
1da177e4 LT	104	{
	105	Elf_Shdr *symtab;
	106	Elf_Sym *symbols;
	107	Elf_Rela *rela;
	108	char *strings;
	109	int nrela, i, j;
	110
	111	/* Find symbol table and string table. */
d2c993d8	112	symtab = NULL;
1da177e4 LT	113	for (i = 0; i < hdr->e_shnum; i++)
	114	switch (sechdrs[i].sh_type) {
	115	case SHT_SYMTAB:
	116	symtab = sechdrs + i;
	117	break;
	118	}
	119	if (!symtab) {
	120	printk(KERN_ERR "module %s: no symbol table\n", me->name);
	121	return -ENOEXEC;
	122	}
	123
	124	/* Allocate one syminfo structure per symbol. */
	125	me->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym);
42bc47b3 KC	126	me->arch.syminfo = vmalloc(array_size(sizeof(struct mod_arch_syminfo),
42bc47b3 KC	127	me->arch.nsyms));
1da177e4 LT	128	if (!me->arch.syminfo)
	129	return -ENOMEM;
	130	symbols = (void *) hdr + symtab->sh_offset;
	131	strings = (void *) hdr + sechdrs[symtab->sh_link].sh_offset;
	132	for (i = 0; i < me->arch.nsyms; i++) {
	133	if (symbols[i].st_shndx == SHN_UNDEF &&
	134	strcmp(strings + symbols[i].st_name,
	135	"_GLOBAL_OFFSET_TABLE_") == 0)
	136	/* "Define" it as absolute. */
	137	symbols[i].st_shndx = SHN_ABS;
	138	me->arch.syminfo[i].got_offset = -1UL;
	139	me->arch.syminfo[i].plt_offset = -1UL;
	140	me->arch.syminfo[i].got_initialized = 0;
	141	me->arch.syminfo[i].plt_initialized = 0;
	142	}
	143
	144	/* Search for got/plt relocations. */
	145	me->arch.got_size = me->arch.plt_size = 0;
	146	for (i = 0; i < hdr->e_shnum; i++) {
	147	if (sechdrs[i].sh_type != SHT_RELA)
	148	continue;
	149	nrela = sechdrs[i].sh_size / sizeof(Elf_Rela);
	150	rela = (void *) hdr + sechdrs[i].sh_offset;
	151	for (j = 0; j < nrela; j++)
	152	check_rela(rela + j, me);
	153	}
	154
	155	/* Increase core size by size of got & plt and set start
	156	offsets for got and plt. */
7523e4dc RR	157	me->core_layout.size = ALIGN(me->core_layout.size, 4);
	158	me->arch.got_offset = me->core_layout.size;
	159	me->core_layout.size += me->arch.got_size;
	160	me->arch.plt_offset = me->core_layout.size;
f19fbd5e	161	if (me->arch.plt_size) {
6e179d64	162	if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_disable)
f19fbd5e MS	163	me->arch.plt_size += PLT_ENTRY_SIZE;
	164	me->core_layout.size += me->arch.plt_size;
	165	}
1da177e4 LT	166	return 0;
	167	}
	168
083e14c0 MS	169	static int apply_rela_bits(Elf_Addr loc, Elf_Addr val,
	170	int sign, int bits, int shift)
	171	{
	172	unsigned long umax;
	173	long min, max;
	174
	175	if (val & ((1UL << shift) - 1))
	176	return -ENOEXEC;
	177	if (sign) {
	178	val = (Elf_Addr)(((long) val) >> shift);
	179	min = -(1L << (bits - 1));
	180	max = (1L << (bits - 1)) - 1;
	181	if ((long) val < min \|\| (long) val > max)
	182	return -ENOEXEC;
	183	} else {
	184	val >>= shift;
	185	umax = ((1UL << (bits - 1)) << 1) - 1;
	186	if ((unsigned long) val > umax)
	187	return -ENOEXEC;
	188	}
	189
	190	if (bits == 8)
	191	(unsigned char ) loc = val;
	192	else if (bits == 12)
	193	(unsigned short ) loc = (val & 0xfff) \|
	194	((unsigned short ) loc & 0xf000);
	195	else if (bits == 16)
	196	(unsigned short ) loc = val;
	197	else if (bits == 20)
	198	(unsigned int ) loc = (val & 0xfff) << 16 \|
	199	(val & 0xff000) >> 4 \|
	200	((unsigned int ) loc & 0xf00000ff);
	201	else if (bits == 32)
	202	(unsigned int ) loc = val;
	203	else if (bits == 64)
	204	(unsigned long ) loc = val;
	205	return 0;
	206	}
	207
	208	static int apply_rela(Elf_Rela rela, Elf_Addr base, Elf_Sym symtab,
	209	const char strtab, struct module me)
1da177e4 LT	210	{
	211	struct mod_arch_syminfo *info;
	212	Elf_Addr loc, val;
	213	int r_type, r_sym;
72a6b43e	214	int rc = -ENOEXEC;
1da177e4 LT	215
	216	/* This is where to make the change */
	217	loc = base + rela->r_offset;
	218	/* This is the symbol it is referring to. Note that all
	219	undefined symbols have been resolved. */
	220	r_sym = ELF_R_SYM(rela->r_info);
	221	r_type = ELF_R_TYPE(rela->r_info);
	222	info = me->arch.syminfo + r_sym;
	223	val = symtab[r_sym].st_value;
	224
	225	switch (r_type) {
e80cfc31 HB	226	case R_390_NONE: /* No relocation. */
	227	rc = 0;
	228	break;
1da177e4 LT	229	case R_390_8: /* Direct 8 bit. */
	230	case R_390_12: /* Direct 12 bit. */
	231	case R_390_16: /* Direct 16 bit. */
	232	case R_390_20: /* Direct 20 bit. */
	233	case R_390_32: /* Direct 32 bit. */
	234	case R_390_64: /* Direct 64 bit. */
	235	val += rela->r_addend;
	236	if (r_type == R_390_8)
083e14c0	237	rc = apply_rela_bits(loc, val, 0, 8, 0);
1da177e4	238	else if (r_type == R_390_12)
083e14c0	239	rc = apply_rela_bits(loc, val, 0, 12, 0);
1da177e4	240	else if (r_type == R_390_16)
083e14c0	241	rc = apply_rela_bits(loc, val, 0, 16, 0);
1da177e4	242	else if (r_type == R_390_20)
083e14c0	243	rc = apply_rela_bits(loc, val, 1, 20, 0);
1da177e4	244	else if (r_type == R_390_32)
083e14c0	245	rc = apply_rela_bits(loc, val, 0, 32, 0);
1da177e4	246	else if (r_type == R_390_64)
083e14c0	247	rc = apply_rela_bits(loc, val, 0, 64, 0);
1da177e4 LT	248	break;
	249	case R_390_PC16: /* PC relative 16 bit. */
	250	case R_390_PC16DBL: /* PC relative 16 bit shifted by 1. */
	251	case R_390_PC32DBL: /* PC relative 32 bit shifted by 1. */
	252	case R_390_PC32: /* PC relative 32 bit. */
	253	case R_390_PC64: /* PC relative 64 bit. */
	254	val += rela->r_addend - loc;
	255	if (r_type == R_390_PC16)
083e14c0	256	rc = apply_rela_bits(loc, val, 1, 16, 0);
1da177e4	257	else if (r_type == R_390_PC16DBL)
083e14c0	258	rc = apply_rela_bits(loc, val, 1, 16, 1);
1da177e4	259	else if (r_type == R_390_PC32DBL)
083e14c0	260	rc = apply_rela_bits(loc, val, 1, 32, 1);
1da177e4	261	else if (r_type == R_390_PC32)
083e14c0	262	rc = apply_rela_bits(loc, val, 1, 32, 0);
1da177e4	263	else if (r_type == R_390_PC64)
083e14c0	264	rc = apply_rela_bits(loc, val, 1, 64, 0);
1da177e4 LT	265	break;
	266	case R_390_GOT12: /* 12 bit GOT offset. */
	267	case R_390_GOT16: /* 16 bit GOT offset. */
	268	case R_390_GOT20: /* 20 bit GOT offset. */
	269	case R_390_GOT32: /* 32 bit GOT offset. */
	270	case R_390_GOT64: /* 64 bit GOT offset. */
	271	case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */
	272	case R_390_GOTPLT12: /* 12 bit offset to jump slot. */
	273	case R_390_GOTPLT20: /* 20 bit offset to jump slot. */
	274	case R_390_GOTPLT16: /* 16 bit offset to jump slot. */
	275	case R_390_GOTPLT32: /* 32 bit offset to jump slot. */
	276	case R_390_GOTPLT64: /* 64 bit offset to jump slot. */
	277	case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */
	278	if (info->got_initialized == 0) {
	279	Elf_Addr *gotent;
	280
7523e4dc	281	gotent = me->core_layout.base + me->arch.got_offset +
1da177e4 LT	282	info->got_offset;
	283	*gotent = val;
	284	info->got_initialized = 1;
	285	}
	286	val = info->got_offset + rela->r_addend;
	287	if (r_type == R_390_GOT12 \|\|
	288	r_type == R_390_GOTPLT12)
083e14c0	289	rc = apply_rela_bits(loc, val, 0, 12, 0);
1da177e4 LT	290	else if (r_type == R_390_GOT16 \|\|
1da177e4 LT	291	r_type == R_390_GOTPLT16)
083e14c0	292	rc = apply_rela_bits(loc, val, 0, 16, 0);
1da177e4 LT	293	else if (r_type == R_390_GOT20 \|\|
1da177e4 LT	294	r_type == R_390_GOTPLT20)
083e14c0	295	rc = apply_rela_bits(loc, val, 1, 20, 0);
1da177e4 LT	296	else if (r_type == R_390_GOT32 \|\|
1da177e4 LT	297	r_type == R_390_GOTPLT32)
083e14c0	298	rc = apply_rela_bits(loc, val, 0, 32, 0);
1da177e4 LT	299	else if (r_type == R_390_GOT64 \|\|
1da177e4 LT	300	r_type == R_390_GOTPLT64)
083e14c0 MS	301	rc = apply_rela_bits(loc, val, 0, 64, 0);
	302	else if (r_type == R_390_GOTENT \|\|
	303	r_type == R_390_GOTPLTENT) {
7523e4dc	304	val += (Elf_Addr) me->core_layout.base - loc;
083e14c0 MS	305	rc = apply_rela_bits(loc, val, 1, 32, 1);
083e14c0 MS	306	}
1da177e4 LT	307	break;
	308	case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */
	309	case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */
	310	case R_390_PLT32: /* 32 bit PC relative PLT address. */
	311	case R_390_PLT64: /* 64 bit PC relative PLT address. */
	312	case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */
	313	case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */
	314	case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */
	315	if (info->plt_initialized == 0) {
	316	unsigned int *ip;
7523e4dc	317	ip = me->core_layout.base + me->arch.plt_offset +
1da177e4	318	info->plt_offset;
f19fbd5e MS	319	ip[0] = 0x0d10e310; /* basr 1,0 */
f19fbd5e MS	320	ip[1] = 0x100a0004; /* lg 1,10(1) */
6e179d64	321	if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_disable) {
f19fbd5e MS	322	unsigned int *ij;
	323	ij = me->core_layout.base +
	324	me->arch.plt_offset +
	325	me->arch.plt_size - PLT_ENTRY_SIZE;
	326	ip[2] = 0xa7f40000 + /* j __jump_r1 */
	327	(unsigned int)(u16)
	328	(((unsigned long) ij - 8 -
	329	(unsigned long) ip) / 2);
	330	} else {
	331	ip[2] = 0x07f10000; /* br %r1 */
	332	}
1da177e4 LT	333	ip[3] = (unsigned int) (val >> 32);
1da177e4 LT	334	ip[4] = (unsigned int) val;
1da177e4 LT	335	info->plt_initialized = 1;
	336	}
	337	if (r_type == R_390_PLTOFF16 \|\|
504665a9 MS	338	r_type == R_390_PLTOFF32 \|\|
504665a9 MS	339	r_type == R_390_PLTOFF64)
1da177e4 LT	340	val = me->arch.plt_offset - me->arch.got_offset +
1da177e4 LT	341	info->plt_offset + rela->r_addend;
504665a9 MS	342	else {
	343	if (!((r_type == R_390_PLT16DBL &&
	344	val - loc + 0xffffUL < 0x1ffffeUL) \|\|
	345	(r_type == R_390_PLT32DBL &&
	346	val - loc + 0xffffffffULL < 0x1fffffffeULL)))
7523e4dc	347	val = (Elf_Addr) me->core_layout.base +
504665a9 MS	348	me->arch.plt_offset +
	349	info->plt_offset;
	350	val += rela->r_addend - loc;
	351	}
1da177e4	352	if (r_type == R_390_PLT16DBL)
083e14c0	353	rc = apply_rela_bits(loc, val, 1, 16, 1);
1da177e4	354	else if (r_type == R_390_PLTOFF16)
083e14c0	355	rc = apply_rela_bits(loc, val, 0, 16, 0);
1da177e4	356	else if (r_type == R_390_PLT32DBL)
083e14c0	357	rc = apply_rela_bits(loc, val, 1, 32, 1);
1da177e4 LT	358	else if (r_type == R_390_PLT32 \|\|
1da177e4 LT	359	r_type == R_390_PLTOFF32)
083e14c0	360	rc = apply_rela_bits(loc, val, 0, 32, 0);
1da177e4 LT	361	else if (r_type == R_390_PLT64 \|\|
1da177e4 LT	362	r_type == R_390_PLTOFF64)
083e14c0	363	rc = apply_rela_bits(loc, val, 0, 64, 0);
1da177e4 LT	364	break;
	365	case R_390_GOTOFF16: /* 16 bit offset to GOT. */
	366	case R_390_GOTOFF32: /* 32 bit offset to GOT. */
	367	case R_390_GOTOFF64: /* 64 bit offset to GOT. */
	368	val = val + rela->r_addend -
7523e4dc	369	((Elf_Addr) me->core_layout.base + me->arch.got_offset);
1da177e4	370	if (r_type == R_390_GOTOFF16)
083e14c0	371	rc = apply_rela_bits(loc, val, 0, 16, 0);
1da177e4	372	else if (r_type == R_390_GOTOFF32)
083e14c0	373	rc = apply_rela_bits(loc, val, 0, 32, 0);
1da177e4	374	else if (r_type == R_390_GOTOFF64)
083e14c0	375	rc = apply_rela_bits(loc, val, 0, 64, 0);
1da177e4 LT	376	break;
	377	case R_390_GOTPC: /* 32 bit PC relative offset to GOT. */
	378	case R_390_GOTPCDBL: /* 32 bit PC rel. off. to GOT shifted by 1. */
7523e4dc	379	val = (Elf_Addr) me->core_layout.base + me->arch.got_offset +
1da177e4 LT	380	rela->r_addend - loc;
1da177e4 LT	381	if (r_type == R_390_GOTPC)
083e14c0	382	rc = apply_rela_bits(loc, val, 1, 32, 0);
1da177e4	383	else if (r_type == R_390_GOTPCDBL)
083e14c0	384	rc = apply_rela_bits(loc, val, 1, 32, 1);
1da177e4 LT	385	break;
	386	case R_390_COPY:
	387	case R_390_GLOB_DAT: /* Create GOT entry. */
	388	case R_390_JMP_SLOT: /* Create PLT entry. */
	389	case R_390_RELATIVE: /* Adjust by program base. */
	390	/* Only needed if we want to support loading of
	391	modules linked with -shared. */
083e14c0	392	return -ENOEXEC;
1da177e4	393	default:
083e14c0	394	printk(KERN_ERR "module %s: unknown relocation: %u\n",
1da177e4 LT	395	me->name, r_type);
	396	return -ENOEXEC;
	397	}
083e14c0 MS	398	if (rc) {
	399	printk(KERN_ERR "module %s: relocation error for symbol %s "
	400	"(r_type %i, value 0x%lx)\n",
	401	me->name, strtab + symtab[r_sym].st_name,
	402	r_type, (unsigned long) val);
	403	return rc;
	404	}
1da177e4 LT	405	return 0;
	406	}
	407
083e14c0 MS	408	int apply_relocate_add(Elf_Shdr sechdrs, const char strtab,
	409	unsigned int symindex, unsigned int relsec,
	410	struct module *me)
1da177e4 LT	411	{
	412	Elf_Addr base;
	413	Elf_Sym *symtab;
	414	Elf_Rela *rela;
	415	unsigned long i, n;
	416	int rc;
	417
	418	DEBUGP("Applying relocate section %u to %u\n",
	419	relsec, sechdrs[relsec].sh_info);
	420	base = sechdrs[sechdrs[relsec].sh_info].sh_addr;
	421	symtab = (Elf_Sym *) sechdrs[symindex].sh_addr;
	422	rela = (Elf_Rela *) sechdrs[relsec].sh_addr;
	423	n = sechdrs[relsec].sh_size / sizeof(Elf_Rela);
	424
	425	for (i = 0; i < n; i++, rela++) {
083e14c0	426	rc = apply_rela(rela, base, symtab, strtab, me);
1da177e4 LT	427	if (rc)
	428	return rc;
	429	}
	430	return 0;
	431	}
	432
	433	int module_finalize(const Elf_Ehdr *hdr,
	434	const Elf_Shdr *sechdrs,
	435	struct module *me)
	436	{
686140a1	437	const Elf_Shdr *s;
f19fbd5e MS	438	char secstrings, secname;
	439	void *aseg;
	440
	441	if (IS_ENABLED(CONFIG_EXPOLINE) &&
6e179d64	442	!nospec_disable && me->arch.plt_size) {
f19fbd5e MS	443	unsigned int *ij;
	444
	445	ij = me->core_layout.base + me->arch.plt_offset +
	446	me->arch.plt_size - PLT_ENTRY_SIZE;
	447	if (test_facility(35)) {
	448	ij[0] = 0xc6000000; /* exrl %r0,.+10 */
	449	ij[1] = 0x0005a7f4; /* j . */
	450	ij[2] = 0x000007f1; /* br %r1 */
	451	} else {
	452	ij[0] = 0x44000000 \| (unsigned int)
	453	offsetof(struct lowcore, br_r1_trampoline);
	454	ij[1] = 0xa7f40000; /* j . */
	455	}
	456	}
686140a1	457
049a2c2d HC	458	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
049a2c2d HC	459	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
f19fbd5e MS	460	aseg = (void *) s->sh_addr;
f19fbd5e MS	461	secname = secstrings + s->sh_name;
686140a1	462
f19fbd5e MS	463	if (!strcmp(".altinstructions", secname))
f19fbd5e MS	464	/* patch .altinstructions */
049a2c2d	465	apply_alternatives(aseg, aseg + s->sh_size);
f19fbd5e MS	466
f19fbd5e MS	467	if (IS_ENABLED(CONFIG_EXPOLINE) &&
6cf09958	468	(!strncmp(".s390_indirect", secname, 14)))
6e179d64	469	nospec_revert(aseg, aseg + s->sh_size);
f19fbd5e MS	470
f19fbd5e MS	471	if (IS_ENABLED(CONFIG_EXPOLINE) &&
6cf09958	472	(!strncmp(".s390_return", secname, 12)))
6e179d64	473	nospec_revert(aseg, aseg + s->sh_size);
686140a1 VG	474	}
686140a1 VG	475
6f367769	476	jump_label_apply_nops(me);
5336377d	477	return 0;
1da177e4	478	}