[linux-2.6-block.git] / arch / mips / kernel / module.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *
 *  Copyright (C) 2001 Rusty Russell.
 *  Copyright (C) 2003, 2004 Ralf Baechle (ralf@linux-mips.org)
 *  Copyright (C) 2005 Thiemo Seufer
 */

#undef DEBUG

#include <linux/extable.h>
#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/mm.h>
#include <linux/numa.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/jump_label.h>
#include <asm/jump_label.h>

struct mips_hi16 {
	struct mips_hi16 *next;
	Elf_Addr *addr;
	Elf_Addr value;
};

static LIST_HEAD(dbe_list);
static DEFINE_SPINLOCK(dbe_lock);

static void apply_r_mips_32(u32 *location, u32 base, Elf_Addr v)
{
	*location = base + v;
}

static int apply_r_mips_26(struct module *me, u32 *location, u32 base,
			   Elf_Addr v)
{
	if (v % 4) {
		pr_err("module %s: dangerous R_MIPS_26 relocation\n",
		       me->name);
		return -ENOEXEC;
	}

	if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
		pr_err("module %s: relocation overflow\n",
		       me->name);
		return -ENOEXEC;
	}

	*location = (*location & ~0x03ffffff) |
		    ((base + (v >> 2)) & 0x03ffffff);

	return 0;
}

static int apply_r_mips_hi16(struct module *me, u32 *location, Elf_Addr v,
			     bool rela)
{
	struct mips_hi16 *n;

	if (rela) {
		*location = (*location & 0xffff0000) |
			    ((((long long) v + 0x8000LL) >> 16) & 0xffff);
		return 0;
	}

	/*
	 * We cannot relocate this one now because we don't know the value of
	 * the carry we need to add.  Save the information, and let LO16 do the
	 * actual relocation.
	 */
	n = kmalloc(sizeof *n, GFP_KERNEL);
	if (!n)
		return -ENOMEM;

	n->addr = (Elf_Addr *)location;
	n->value = v;
	n->next = me->arch.r_mips_hi16_list;
	me->arch.r_mips_hi16_list = n;

	return 0;
}

static void free_relocation_chain(struct mips_hi16 *l)
{
	struct mips_hi16 *next;

	while (l) {
		next = l->next;
		kfree(l);
		l = next;
	}
}

static int apply_r_mips_lo16(struct module *me, u32 *location,
			     u32 base, Elf_Addr v, bool rela)
{
	unsigned long insnlo = base;
	struct mips_hi16 *l;
	Elf_Addr val, vallo;

	if (rela) {
		*location = (*location & 0xffff0000) | (v & 0xffff);
		return 0;
	}

	/* Sign extend the addend we extract from the lo insn.	*/
	vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;

	if (me->arch.r_mips_hi16_list != NULL) {
		l = me->arch.r_mips_hi16_list;
		while (l != NULL) {
			struct mips_hi16 *next;
			unsigned long insn;

			/*
			 * The value for the HI16 had best be the same.
			 */
			if (v != l->value)
				goto out_danger;

			/*
			 * Do the HI16 relocation.  Note that we actually don't
			 * need to know anything about the LO16 itself, except
			 * where to find the low 16 bits of the addend needed
			 * by the LO16.
			 */
			insn = *l->addr;
			val = ((insn & 0xffff) << 16) + vallo;
			val += v;

			/*
			 * Account for the sign extension that will happen in
			 * the low bits.
			 */
			val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;

			insn = (insn & ~0xffff) | val;
			*l->addr = insn;

			next = l->next;
			kfree(l);
			l = next;
		}

		me->arch.r_mips_hi16_list = NULL;
	}

	/*
	 * Ok, we're done with the HI16 relocs.	 Now deal with the LO16.
	 */
	val = v + vallo;
	insnlo = (insnlo & ~0xffff) | (val & 0xffff);
	*location = insnlo;

	return 0;

out_danger:
	free_relocation_chain(l);
	me->arch.r_mips_hi16_list = NULL;

	pr_err("module %s: dangerous R_MIPS_LO16 relocation\n", me->name);

	return -ENOEXEC;
}

static int apply_r_mips_pc(struct module *me, u32 *location, u32 base,
			   Elf_Addr v, unsigned int bits)
{
	unsigned long mask = GENMASK(bits - 1, 0);
	unsigned long se_bits;
	long offset;

	if (v % 4) {
		pr_err("module %s: dangerous R_MIPS_PC%u relocation\n",
		       me->name, bits);
		return -ENOEXEC;
	}

	/* retrieve & sign extend implicit addend if any */
	offset = base & mask;
	offset |= (offset & BIT(bits - 1)) ? ~mask : 0;

	offset += ((long)v - (long)location) >> 2;

	/* check the sign bit onwards are identical - ie. we didn't overflow */
	se_bits = (offset & BIT(bits - 1)) ? ~0ul : 0;
	if ((offset & ~mask) != (se_bits & ~mask)) {
		pr_err("module %s: relocation overflow\n", me->name);
		return -ENOEXEC;
	}

	*location = (*location & ~mask) | (offset & mask);

	return 0;
}

static int apply_r_mips_pc16(struct module *me, u32 *location, u32 base,
			     Elf_Addr v)
{
	return apply_r_mips_pc(me, location, base, v, 16);
}

static int apply_r_mips_pc21(struct module *me, u32 *location, u32 base,
			     Elf_Addr v)
{
	return apply_r_mips_pc(me, location, base, v, 21);
}

static int apply_r_mips_pc26(struct module *me, u32 *location, u32 base,
			     Elf_Addr v)
{
	return apply_r_mips_pc(me, location, base, v, 26);
}

static int apply_r_mips_64(u32 *location, Elf_Addr v, bool rela)
{
	if (WARN_ON(!rela))
		return -EINVAL;

	*(Elf_Addr *)location = v;

	return 0;
}

static int apply_r_mips_higher(u32 *location, Elf_Addr v, bool rela)
{
	if (WARN_ON(!rela))
		return -EINVAL;

	*location = (*location & 0xffff0000) |
		    ((((long long)v + 0x80008000LL) >> 32) & 0xffff);

	return 0;
}

static int apply_r_mips_highest(u32 *location, Elf_Addr v, bool rela)
{
	if (WARN_ON(!rela))
		return -EINVAL;

	*location = (*location & 0xffff0000) |
		    ((((long long)v + 0x800080008000LL) >> 48) & 0xffff);

	return 0;
}

/**
 * reloc_handler() - Apply a particular relocation to a module
 * @type: type of the relocation to apply
 * @me: the module to apply the reloc to
 * @location: the address at which the reloc is to be applied
 * @base: the existing value at location for REL-style; 0 for RELA-style
 * @v: the value of the reloc, with addend for RELA-style
 * @rela: indication of is this a RELA (true) or REL (false) relocation
 *
 * Each implemented relocation function applies a particular type of
 * relocation to the module @me. Relocs that may be found in either REL or RELA
 * variants can be handled by making use of the @base & @v parameters which are
 * set to values which abstract the difference away from the particular reloc
 * implementations.
 *
 * Return: 0 upon success, else -ERRNO
 */
static int reloc_handler(u32 type, struct module *me, u32 *location, u32 base,
			 Elf_Addr v, bool rela)
{
	switch (type) {
	case R_MIPS_NONE:
		break;
	case R_MIPS_32:
		apply_r_mips_32(location, base, v);
		break;
	case R_MIPS_26:
		return apply_r_mips_26(me, location, base, v);
	case R_MIPS_HI16:
		return apply_r_mips_hi16(me, location, v, rela);
	case R_MIPS_LO16:
		return apply_r_mips_lo16(me, location, base, v, rela);
	case R_MIPS_PC16:
		return apply_r_mips_pc16(me, location, base, v);
	case R_MIPS_PC21_S2:
		return apply_r_mips_pc21(me, location, base, v);
	case R_MIPS_PC26_S2:
		return apply_r_mips_pc26(me, location, base, v);
	case R_MIPS_64:
		return apply_r_mips_64(location, v, rela);
	case R_MIPS_HIGHER:
		return apply_r_mips_higher(location, v, rela);
	case R_MIPS_HIGHEST:
		return apply_r_mips_highest(location, v, rela);
	default:
		pr_err("%s: Unknown relocation type %u\n", me->name, type);
		return -EINVAL;
	}

	return 0;
}

static int __apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
			    unsigned int symindex, unsigned int relsec,
			    struct module *me, bool rela)
{
	union {
		Elf_Mips_Rel *rel;
		Elf_Mips_Rela *rela;
	} r;
	Elf_Sym *sym;
	u32 *location, base;
	unsigned int i, type;
	Elf_Addr v;
	int err = 0;
	size_t reloc_sz;

	pr_debug("Applying relocate section %u to %u\n", relsec,
	       sechdrs[relsec].sh_info);

	r.rel = (void *)sechdrs[relsec].sh_addr;
	reloc_sz = rela ? sizeof(*r.rela) : sizeof(*r.rel);
	me->arch.r_mips_hi16_list = NULL;
	for (i = 0; i < sechdrs[relsec].sh_size / reloc_sz; i++) {
		/* This is where to make the change */
		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
			+ r.rel->r_offset;
		/* This is the symbol it is referring to */
		sym = (Elf_Sym *)sechdrs[symindex].sh_addr
			+ ELF_MIPS_R_SYM(*r.rel);
		if (sym->st_value >= -MAX_ERRNO) {
			/* Ignore unresolved weak symbol */
			if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
				continue;
			pr_warn("%s: Unknown symbol %s\n",
				me->name, strtab + sym->st_name);
			err = -ENOENT;
			goto out;
		}

		type = ELF_MIPS_R_TYPE(*r.rel);

		if (rela) {
			v = sym->st_value + r.rela->r_addend;
			base = 0;
			r.rela = &r.rela[1];
		} else {
			v = sym->st_value;
			base = *location;
			r.rel = &r.rel[1];
		}

		err = reloc_handler(type, me, location, base, v, rela);
		if (err)
			goto out;
	}

out:
	/*
	 * Normally the hi16 list should be deallocated at this point. A
	 * malformed binary however could contain a series of R_MIPS_HI16
	 * relocations not followed by a R_MIPS_LO16 relocation, or if we hit
	 * an error processing a reloc we might have gotten here before
	 * reaching the R_MIPS_LO16. In either case, free up the list and
	 * return an error.
	 */
	if (me->arch.r_mips_hi16_list) {
		free_relocation_chain(me->arch.r_mips_hi16_list);
		me->arch.r_mips_hi16_list = NULL;
		err = err ?: -ENOEXEC;
	}

	return err;
}

int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
		   unsigned int symindex, unsigned int relsec,
		   struct module *me)
{
	return __apply_relocate(sechdrs, strtab, symindex, relsec, me, false);
}

#ifdef CONFIG_MODULES_USE_ELF_RELA
int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
		       unsigned int symindex, unsigned int relsec,
		       struct module *me)
{
	return __apply_relocate(sechdrs, strtab, symindex, relsec, me, true);
}
#endif /* CONFIG_MODULES_USE_ELF_RELA */

/* Given an address, look for it in the module exception tables. */
const struct exception_table_entry *search_module_dbetables(unsigned long addr)
{
	unsigned long flags;
	const struct exception_table_entry *e = NULL;
	struct mod_arch_specific *dbe;

	spin_lock_irqsave(&dbe_lock, flags);
	list_for_each_entry(dbe, &dbe_list, dbe_list) {
		e = search_extable(dbe->dbe_start,
				   dbe->dbe_end - dbe->dbe_start, addr);
		if (e)
			break;
	}
	spin_unlock_irqrestore(&dbe_lock, flags);

	/* Now, if we found one, we are running inside it now, hence
	   we cannot unload the module, hence no refcnt needed. */
	return e;
}

/* Put in dbe list if necessary. */
int module_finalize(const Elf_Ehdr *hdr,
		    const Elf_Shdr *sechdrs,
		    struct module *me)
{
	const Elf_Shdr *s;
	char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;

	if (IS_ENABLED(CONFIG_JUMP_LABEL))
		jump_label_apply_nops(me);

	INIT_LIST_HEAD(&me->arch.dbe_list);
	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
		if (strcmp("__dbe_table", secstrings + s->sh_name) != 0)
			continue;
		me->arch.dbe_start = (void *)s->sh_addr;
		me->arch.dbe_end = (void *)s->sh_addr + s->sh_size;
		spin_lock_irq(&dbe_lock);
		list_add(&me->arch.dbe_list, &dbe_list);
		spin_unlock_irq(&dbe_lock);
	}
	return 0;
}

void module_arch_cleanup(struct module *mod)
{
	spin_lock_irq(&dbe_lock);
	list_del(&mod->arch.dbe_list);
	spin_unlock_irq(&dbe_lock);
}
Commit	Line	Data
1a59d1b8	1	// SPDX-License-Identifier: GPL-2.0-or-later
4e6a05fe	2	/*
4e6a05fe TS	3	*
	4	* Copyright (C) 2001 Rusty Russell.
	5	* Copyright (C) 2003, 2004 Ralf Baechle (ralf@linux-mips.org)
	6	* Copyright (C) 2005 Thiemo Seufer
	7	*/
	8
	9	#undef DEBUG
	10
9f3b8081	11	#include <linux/extable.h>
4e6a05fe TS	12	#include <linux/moduleloader.h>
4e6a05fe TS	13	#include <linux/elf.h>
27ac792c	14	#include <linux/mm.h>
761845f0	15	#include <linux/numa.h>
4e6a05fe TS	16	#include <linux/slab.h>
	17	#include <linux/fs.h>
	18	#include <linux/string.h>
	19	#include <linux/kernel.h>
1da177e4	20	#include <linux/spinlock.h>
94bb0c1a	21	#include <linux/jump_label.h>
ad6eb1ec	22	#include <asm/jump_label.h>
1da177e4	23
4e6a05fe TS	24	struct mips_hi16 {
	25	struct mips_hi16 *next;
	26	Elf_Addr *addr;
	27	Elf_Addr value;
	28	};
	29
1da177e4 LT	30	static LIST_HEAD(dbe_list);
	31	static DEFINE_SPINLOCK(dbe_lock);
	32
049a68ef	33	static void apply_r_mips_32(u32 *location, u32 base, Elf_Addr v)
4e6a05fe	34	{
430d0b88	35	*location = base + v;
4e6a05fe TS	36	}
4e6a05fe TS	37
049a68ef AL	38	static int apply_r_mips_26(struct module me, u32 location, u32 base,
049a68ef AL	39	Elf_Addr v)
4e6a05fe TS	40	{
4e6a05fe TS	41	if (v % 4) {
430d0b88	42	pr_err("module %s: dangerous R_MIPS_26 relocation\n",
6f9fdeb6	43	me->name);
4e6a05fe TS	44	return -ENOEXEC;
	45	}
	46
	47	if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
55d791f3	48	pr_err("module %s: relocation overflow\n",
4e6a05fe TS	49	me->name);
	50	return -ENOEXEC;
	51	}
	52
	53	location = (location & ~0x03ffffff) \|
430d0b88	54	((base + (v >> 2)) & 0x03ffffff);
4e6a05fe TS	55
	56	return 0;
	57	}
	58
049a68ef AL	59	static int apply_r_mips_hi16(struct module me, u32 location, Elf_Addr v,
049a68ef AL	60	bool rela)
4e6a05fe TS	61	{
	62	struct mips_hi16 *n;
	63
430d0b88 PB	64	if (rela) {
	65	location = (location & 0xffff0000) \|
	66	((((long long) v + 0x8000LL) >> 16) & 0xffff);
	67	return 0;
	68	}
	69
4e6a05fe TS	70	/*
	71	* We cannot relocate this one now because we don't know the value of
	72	* the carry we need to add. Save the information, and let LO16 do the
	73	* actual relocation.
	74	*/
	75	n = kmalloc(sizeof *n, GFP_KERNEL);
	76	if (!n)
	77	return -ENOMEM;
	78
	79	n->addr = (Elf_Addr *)location;
	80	n->value = v;
861667dc RB	81	n->next = me->arch.r_mips_hi16_list;
861667dc RB	82	me->arch.r_mips_hi16_list = n;
4e6a05fe TS	83
	84	return 0;
	85	}
	86
c54de490 RB	87	static void free_relocation_chain(struct mips_hi16 *l)
	88	{
	89	struct mips_hi16 *next;
	90
	91	while (l) {
	92	next = l->next;
	93	kfree(l);
	94	l = next;
	95	}
	96	}
	97
430d0b88 PB	98	static int apply_r_mips_lo16(struct module me, u32 location,
430d0b88 PB	99	u32 base, Elf_Addr v, bool rela)
4e6a05fe	100	{
430d0b88	101	unsigned long insnlo = base;
c54de490	102	struct mips_hi16 *l;
4e6a05fe TS	103	Elf_Addr val, vallo;
4e6a05fe TS	104
430d0b88 PB	105	if (rela) {
	106	location = (location & 0xffff0000) \| (v & 0xffff);
	107	return 0;
	108	}
	109
70342287	110	/* Sign extend the addend we extract from the lo insn. */
4e6a05fe TS	111	vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
4e6a05fe TS	112
861667dc	113	if (me->arch.r_mips_hi16_list != NULL) {
861667dc	114	l = me->arch.r_mips_hi16_list;
4e6a05fe	115	while (l != NULL) {
c54de490	116	struct mips_hi16 *next;
4e6a05fe TS	117	unsigned long insn;
	118
	119	/*
	120	* The value for the HI16 had best be the same.
	121	*/
	122	if (v != l->value)
	123	goto out_danger;
	124
	125	/*
	126	* Do the HI16 relocation. Note that we actually don't
	127	* need to know anything about the LO16 itself, except
	128	* where to find the low 16 bits of the addend needed
	129	* by the LO16.
	130	*/
	131	insn = *l->addr;
	132	val = ((insn & 0xffff) << 16) + vallo;
	133	val += v;
	134
	135	/*
	136	* Account for the sign extension that will happen in
	137	* the low bits.
	138	*/
	139	val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
	140
	141	insn = (insn & ~0xffff) \| val;
	142	*l->addr = insn;
	143
	144	next = l->next;
	145	kfree(l);
	146	l = next;
	147	}
	148
861667dc	149	me->arch.r_mips_hi16_list = NULL;
4e6a05fe TS	150	}
	151
	152	/*
70342287	153	* Ok, we're done with the HI16 relocs. Now deal with the LO16.
4e6a05fe TS	154	*/
	155	val = v + vallo;
	156	insnlo = (insnlo & ~0xffff) \| (val & 0xffff);
	157	*location = insnlo;
	158
	159	return 0;
	160
	161	out_danger:
c54de490 RB	162	free_relocation_chain(l);
c54de490 RB	163	me->arch.r_mips_hi16_list = NULL;
d3cac35c	164
430d0b88	165	pr_err("module %s: dangerous R_MIPS_LO16 relocation\n", me->name);
4e6a05fe TS	166
	167	return -ENOEXEC;
	168	}
	169
430d0b88 PB	170	static int apply_r_mips_pc(struct module me, u32 location, u32 base,
430d0b88 PB	171	Elf_Addr v, unsigned int bits)
5d3c7925 PB	172	{
	173	unsigned long mask = GENMASK(bits - 1, 0);
	174	unsigned long se_bits;
	175	long offset;
	176
	177	if (v % 4) {
430d0b88	178	pr_err("module %s: dangerous R_MIPS_PC%u relocation\n",
5d3c7925 PB	179	me->name, bits);
	180	return -ENOEXEC;
	181	}
	182
430d0b88 PB	183	/* retrieve & sign extend implicit addend if any */
430d0b88 PB	184	offset = base & mask;
5d3c7925 PB	185	offset \|= (offset & BIT(bits - 1)) ? ~mask : 0;
	186
	187	offset += ((long)v - (long)location) >> 2;
	188
	189	/* check the sign bit onwards are identical - ie. we didn't overflow */
	190	se_bits = (offset & BIT(bits - 1)) ? ~0ul : 0;
	191	if ((offset & ~mask) != (se_bits & ~mask)) {
	192	pr_err("module %s: relocation overflow\n", me->name);
	193	return -ENOEXEC;
	194	}
	195
	196	location = (location & ~mask) \| (offset & mask);
	197
	198	return 0;
	199	}
	200
049a68ef AL	201	static int apply_r_mips_pc16(struct module me, u32 location, u32 base,
049a68ef AL	202	Elf_Addr v)
5d3c7925	203	{
430d0b88	204	return apply_r_mips_pc(me, location, base, v, 16);
5d3c7925 PB	205	}
5d3c7925 PB	206
049a68ef AL	207	static int apply_r_mips_pc21(struct module me, u32 location, u32 base,
049a68ef AL	208	Elf_Addr v)
5d3c7925	209	{
430d0b88	210	return apply_r_mips_pc(me, location, base, v, 21);
5d3c7925 PB	211	}
5d3c7925 PB	212
049a68ef AL	213	static int apply_r_mips_pc26(struct module me, u32 location, u32 base,
049a68ef AL	214	Elf_Addr v)
5d3c7925	215	{
430d0b88	216	return apply_r_mips_pc(me, location, base, v, 26);
5d3c7925 PB	217	}
5d3c7925 PB	218
049a68ef	219	static int apply_r_mips_64(u32 *location, Elf_Addr v, bool rela)
5d3c7925	220	{
430d0b88 PB	221	if (WARN_ON(!rela))
	222	return -EINVAL;
	223
	224	(Elf_Addr )location = v;
	225
	226	return 0;
5d3c7925 PB	227	}
5d3c7925 PB	228
049a68ef	229	static int apply_r_mips_higher(u32 *location, Elf_Addr v, bool rela)
5d3c7925	230	{
430d0b88 PB	231	if (WARN_ON(!rela))
	232	return -EINVAL;
	233
	234	location = (location & 0xffff0000) \|
	235	((((long long)v + 0x80008000LL) >> 32) & 0xffff);
	236
	237	return 0;
5d3c7925 PB	238	}
5d3c7925 PB	239
049a68ef	240	static int apply_r_mips_highest(u32 *location, Elf_Addr v, bool rela)
5d3c7925	241	{
430d0b88 PB	242	if (WARN_ON(!rela))
	243	return -EINVAL;
	244
	245	location = (location & 0xffff0000) \|
	246	((((long long)v + 0x800080008000LL) >> 48) & 0xffff);
	247
	248	return 0;
5d3c7925 PB	249	}
5d3c7925 PB	250
430d0b88 PB	251	/**
430d0b88 PB	252	* reloc_handler() - Apply a particular relocation to a module
049a68ef	253	* @type: type of the relocation to apply
430d0b88 PB	254	* @me: the module to apply the reloc to
	255	* @location: the address at which the reloc is to be applied
	256	* @base: the existing value at location for REL-style; 0 for RELA-style
	257	* @v: the value of the reloc, with addend for RELA-style
049a68ef	258	* @rela: indication of is this a RELA (true) or REL (false) relocation
430d0b88	259	*
049a68ef	260	* Each implemented relocation function applies a particular type of
430d0b88 PB	261	* relocation to the module @me. Relocs that may be found in either REL or RELA
	262	* variants can be handled by making use of the @base & @v parameters which are
	263	* set to values which abstract the difference away from the particular reloc
	264	* implementations.
	265	*
	266	* Return: 0 upon success, else -ERRNO
	267	*/
049a68ef AL	268	static int reloc_handler(u32 type, struct module me, u32 location, u32 base,
	269	Elf_Addr v, bool rela)
	270	{
	271	switch (type) {
	272	case R_MIPS_NONE:
	273	break;
	274	case R_MIPS_32:
	275	apply_r_mips_32(location, base, v);
	276	break;
	277	case R_MIPS_26:
	278	return apply_r_mips_26(me, location, base, v);
	279	case R_MIPS_HI16:
	280	return apply_r_mips_hi16(me, location, v, rela);
	281	case R_MIPS_LO16:
	282	return apply_r_mips_lo16(me, location, base, v, rela);
	283	case R_MIPS_PC16:
	284	return apply_r_mips_pc16(me, location, base, v);
	285	case R_MIPS_PC21_S2:
	286	return apply_r_mips_pc21(me, location, base, v);
	287	case R_MIPS_PC26_S2:
	288	return apply_r_mips_pc26(me, location, base, v);
	289	case R_MIPS_64:
	290	return apply_r_mips_64(location, v, rela);
	291	case R_MIPS_HIGHER:
	292	return apply_r_mips_higher(location, v, rela);
	293	case R_MIPS_HIGHEST:
	294	return apply_r_mips_highest(location, v, rela);
	295	default:
	296	pr_err("%s: Unknown relocation type %u\n", me->name, type);
	297	return -EINVAL;
	298	}
	299
	300	return 0;
	301	}
4e6a05fe	302
430d0b88 PB	303	static int __apply_relocate(Elf_Shdr sechdrs, const char strtab,
	304	unsigned int symindex, unsigned int relsec,
	305	struct module *me, bool rela)
4e6a05fe	306	{
430d0b88 PB	307	union {
	308	Elf_Mips_Rel *rel;
	309	Elf_Mips_Rela *rela;
	310	} r;
4e6a05fe	311	Elf_Sym *sym;
430d0b88	312	u32 *location, base;
04211a57	313	unsigned int i, type;
4e6a05fe	314	Elf_Addr v;
351b0940	315	int err = 0;
430d0b88	316	size_t reloc_sz;
4e6a05fe TS	317
	318	pr_debug("Applying relocate section %u to %u\n", relsec,
	319	sechdrs[relsec].sh_info);
	320
430d0b88 PB	321	r.rel = (void *)sechdrs[relsec].sh_addr;
430d0b88 PB	322	reloc_sz = rela ? sizeof(r.rela) : sizeof(r.rel);
861667dc	323	me->arch.r_mips_hi16_list = NULL;
430d0b88	324	for (i = 0; i < sechdrs[relsec].sh_size / reloc_sz; i++) {
4e6a05fe TS	325	/* This is where to make the change */
4e6a05fe TS	326	location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
430d0b88	327	+ r.rel->r_offset;
4e6a05fe TS	328	/* This is the symbol it is referring to */
4e6a05fe TS	329	sym = (Elf_Sym *)sechdrs[symindex].sh_addr
430d0b88	330	+ ELF_MIPS_R_SYM(*r.rel);
ba837d38	331	if (sym->st_value >= -MAX_ERRNO) {
f3bf07b9 AN	332	/* Ignore unresolved weak symbol */
	333	if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
	334	continue;
55d791f3 SH	335	pr_warn("%s: Unknown symbol %s\n",
55d791f3 SH	336	me->name, strtab + sym->st_name);
351b0940 PB	337	err = -ENOENT;
351b0940 PB	338	goto out;
4e6a05fe TS	339	}
4e6a05fe TS	340
430d0b88	341	type = ELF_MIPS_R_TYPE(*r.rel);
04211a57	342
430d0b88 PB	343	if (rela) {
	344	v = sym->st_value + r.rela->r_addend;
	345	base = 0;
	346	r.rela = &r.rela[1];
	347	} else {
	348	v = sym->st_value;
	349	base = *location;
	350	r.rel = &r.rel[1];
	351	}
	352
049a68ef	353	err = reloc_handler(type, me, location, base, v, rela);
351b0940 PB	354	if (err)
351b0940 PB	355	goto out;
4e6a05fe TS	356	}
4e6a05fe TS	357
351b0940	358	out:
c54de490	359	/*
351b0940	360	* Normally the hi16 list should be deallocated at this point. A
c54de490	361	* malformed binary however could contain a series of R_MIPS_HI16
351b0940 PB	362	* relocations not followed by a R_MIPS_LO16 relocation, or if we hit
	363	* an error processing a reloc we might have gotten here before
	364	* reaching the R_MIPS_LO16. In either case, free up the list and
	365	* return an error.
c54de490 RB	366	*/
	367	if (me->arch.r_mips_hi16_list) {
	368	free_relocation_chain(me->arch.r_mips_hi16_list);
	369	me->arch.r_mips_hi16_list = NULL;
351b0940	370	err = err ?: -ENOEXEC;
c54de490 RB	371	}
c54de490 RB	372
351b0940	373	return err;
4e6a05fe TS	374	}
4e6a05fe TS	375
430d0b88 PB	376	int apply_relocate(Elf_Shdr sechdrs, const char strtab,
	377	unsigned int symindex, unsigned int relsec,
	378	struct module *me)
	379	{
	380	return __apply_relocate(sechdrs, strtab, symindex, relsec, me, false);
	381	}
	382
	383	#ifdef CONFIG_MODULES_USE_ELF_RELA
	384	int apply_relocate_add(Elf_Shdr sechdrs, const char strtab,
	385	unsigned int symindex, unsigned int relsec,
	386	struct module *me)
	387	{
	388	return __apply_relocate(sechdrs, strtab, symindex, relsec, me, true);
4e6a05fe	389	}
430d0b88	390	#endif /* CONFIG_MODULES_USE_ELF_RELA */
4e6a05fe	391
1da177e4 LT	392	/* Given an address, look for it in the module exception tables. */
	393	const struct exception_table_entry *search_module_dbetables(unsigned long addr)
	394	{
	395	unsigned long flags;
	396	const struct exception_table_entry *e = NULL;
	397	struct mod_arch_specific *dbe;
	398
	399	spin_lock_irqsave(&dbe_lock, flags);
	400	list_for_each_entry(dbe, &dbe_list, dbe_list) {
a94c33dd TM	401	e = search_extable(dbe->dbe_start,
a94c33dd TM	402	dbe->dbe_end - dbe->dbe_start, addr);
1da177e4 LT	403	if (e)
	404	break;
	405	}
	406	spin_unlock_irqrestore(&dbe_lock, flags);
	407
	408	/* Now, if we found one, we are running inside it now, hence
70342287	409	we cannot unload the module, hence no refcnt needed. */
1da177e4 LT	410	return e;
	411	}
	412
3a4fa0a2	413	/* Put in dbe list if necessary. */
1da177e4 LT	414	int module_finalize(const Elf_Ehdr *hdr,
	415	const Elf_Shdr *sechdrs,
	416	struct module *me)
	417	{
	418	const Elf_Shdr *s;
	419	char secstrings = (void )hdr + sechdrs[hdr->e_shstrndx].sh_offset;
	420
fdfd4289 AB	421	if (IS_ENABLED(CONFIG_JUMP_LABEL))
fdfd4289 AB	422	jump_label_apply_nops(me);
94bb0c1a	423
1da177e4 LT	424	INIT_LIST_HEAD(&me->arch.dbe_list);
	425	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
	426	if (strcmp("__dbe_table", secstrings + s->sh_name) != 0)
	427	continue;
	428	me->arch.dbe_start = (void *)s->sh_addr;
	429	me->arch.dbe_end = (void *)s->sh_addr + s->sh_size;
	430	spin_lock_irq(&dbe_lock);
	431	list_add(&me->arch.dbe_list, &dbe_list);
	432	spin_unlock_irq(&dbe_lock);
	433	}
	434	return 0;
	435	}
	436
	437	void module_arch_cleanup(struct module *mod)
	438	{
	439	spin_lock_irq(&dbe_lock);
	440	list_del(&mod->arch.dbe_list);
	441	spin_unlock_irq(&dbe_lock);
	442	}