[mirror_ubuntu-hirsute-kernel.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/vmalloc.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/pgtable.h>	/* MODULE_START */

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

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

#ifdef MODULE_START
void *module_alloc(unsigned long size)
{
	return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
				GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
				__builtin_return_address(0));
}
#endif

static int apply_r_mips_none(struct module *me, u32 *location,
			     u32 base, Elf_Addr v, bool rela)
{
	return 0;
}

static int apply_r_mips_32(struct module *me, u32 *location,
			   u32 base, Elf_Addr v, bool rela)
{
	*location = base + v;

	return 0;
}

static int apply_r_mips_26(struct module *me, u32 *location,
			   u32 base, Elf_Addr v, bool rela)
{
	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,
			     u32 base, 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, bool rela)
{
	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, bool rela)
{
	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, bool rela)
{
	return apply_r_mips_pc(me, location, base, v, 26);
}

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

	*(Elf_Addr *)location = v;

	return 0;
}

static int apply_r_mips_higher(struct module *me, u32 *location,
			       u32 base, 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(struct module *me, u32 *location,
				u32 base, 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
 * @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
 *
 * Each implemented reloc_handler 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
 */
typedef int (*reloc_handler)(struct module *me, u32 *location,
			     u32 base, Elf_Addr v, bool rela);

/* The handlers for known reloc types */
static reloc_handler reloc_handlers[] = {
	[R_MIPS_NONE]		= apply_r_mips_none,
	[R_MIPS_32]		= apply_r_mips_32,
	[R_MIPS_26]		= apply_r_mips_26,
	[R_MIPS_HI16]		= apply_r_mips_hi16,
	[R_MIPS_LO16]		= apply_r_mips_lo16,
	[R_MIPS_PC16]		= apply_r_mips_pc16,
	[R_MIPS_64]		= apply_r_mips_64,
	[R_MIPS_HIGHER]		= apply_r_mips_higher,
	[R_MIPS_HIGHEST]	= apply_r_mips_highest,
	[R_MIPS_PC21_S2]	= apply_r_mips_pc21,
	[R_MIPS_PC26_S2]	= apply_r_mips_pc26,
};

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;
	reloc_handler handler;
	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 (type < ARRAY_SIZE(reloc_handlers))
			handler = reloc_handlers[type];
		else
			handler = NULL;

		if (!handler) {
			pr_err("%s: Unknown relocation type %u\n",
			       me->name, type);
			err = -EINVAL;
			goto out;
		}

		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 = handler(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;

	/* Make jump label nops. */
	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/vmalloc.h>
	17	#include <linux/slab.h>
	18	#include <linux/fs.h>
	19	#include <linux/string.h>
	20	#include <linux/kernel.h>
1da177e4	21	#include <linux/spinlock.h>
94bb0c1a DD	22	#include <linux/jump_label.h>
94bb0c1a DD	23
656be92f	24	#include <asm/pgtable.h> /* MODULE_START */
1da177e4	25
4e6a05fe TS	26	struct mips_hi16 {
	27	struct mips_hi16 *next;
	28	Elf_Addr *addr;
	29	Elf_Addr value;
	30	};
	31
1da177e4 LT	32	static LIST_HEAD(dbe_list);
	33	static DEFINE_SPINLOCK(dbe_lock);
	34
66574cc0	35	#ifdef MODULE_START
4e6a05fe TS	36	void *module_alloc(unsigned long size)
4e6a05fe TS	37	{
d0a21265	38	return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
cb9e3c29	39	GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
d0a21265	40	__builtin_return_address(0));
4e6a05fe	41	}
66574cc0	42	#endif
4e6a05fe	43
430d0b88 PB	44	static int apply_r_mips_none(struct module me, u32 location,
430d0b88 PB	45	u32 base, Elf_Addr v, bool rela)
4e6a05fe TS	46	{
	47	return 0;
	48	}
	49
430d0b88 PB	50	static int apply_r_mips_32(struct module me, u32 location,
430d0b88 PB	51	u32 base, Elf_Addr v, bool rela)
4e6a05fe	52	{
430d0b88	53	*location = base + v;
4e6a05fe TS	54
	55	return 0;
	56	}
	57
430d0b88 PB	58	static int apply_r_mips_26(struct module me, u32 location,
430d0b88 PB	59	u32 base, Elf_Addr v, bool rela)
4e6a05fe TS	60	{
4e6a05fe TS	61	if (v % 4) {
430d0b88	62	pr_err("module %s: dangerous R_MIPS_26 relocation\n",
6f9fdeb6	63	me->name);
4e6a05fe TS	64	return -ENOEXEC;
	65	}
	66
	67	if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
55d791f3	68	pr_err("module %s: relocation overflow\n",
4e6a05fe TS	69	me->name);
	70	return -ENOEXEC;
	71	}
	72
	73	location = (location & ~0x03ffffff) \|
430d0b88	74	((base + (v >> 2)) & 0x03ffffff);
4e6a05fe TS	75
	76	return 0;
	77	}
	78
430d0b88 PB	79	static int apply_r_mips_hi16(struct module me, u32 location,
430d0b88 PB	80	u32 base, Elf_Addr v, bool rela)
4e6a05fe TS	81	{
	82	struct mips_hi16 *n;
	83
430d0b88 PB	84	if (rela) {
	85	location = (location & 0xffff0000) \|
	86	((((long long) v + 0x8000LL) >> 16) & 0xffff);
	87	return 0;
	88	}
	89
4e6a05fe TS	90	/*
	91	* We cannot relocate this one now because we don't know the value of
	92	* the carry we need to add. Save the information, and let LO16 do the
	93	* actual relocation.
	94	*/
	95	n = kmalloc(sizeof *n, GFP_KERNEL);
	96	if (!n)
	97	return -ENOMEM;
	98
	99	n->addr = (Elf_Addr *)location;
	100	n->value = v;
861667dc RB	101	n->next = me->arch.r_mips_hi16_list;
861667dc RB	102	me->arch.r_mips_hi16_list = n;
4e6a05fe TS	103
	104	return 0;
	105	}
	106
c54de490 RB	107	static void free_relocation_chain(struct mips_hi16 *l)
	108	{
	109	struct mips_hi16 *next;
	110
	111	while (l) {
	112	next = l->next;
	113	kfree(l);
	114	l = next;
	115	}
	116	}
	117
430d0b88 PB	118	static int apply_r_mips_lo16(struct module me, u32 location,
430d0b88 PB	119	u32 base, Elf_Addr v, bool rela)
4e6a05fe	120	{
430d0b88	121	unsigned long insnlo = base;
c54de490	122	struct mips_hi16 *l;
4e6a05fe TS	123	Elf_Addr val, vallo;
4e6a05fe TS	124
430d0b88 PB	125	if (rela) {
	126	location = (location & 0xffff0000) \| (v & 0xffff);
	127	return 0;
	128	}
	129
70342287	130	/* Sign extend the addend we extract from the lo insn. */
4e6a05fe TS	131	vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
4e6a05fe TS	132
861667dc	133	if (me->arch.r_mips_hi16_list != NULL) {
861667dc	134	l = me->arch.r_mips_hi16_list;
4e6a05fe	135	while (l != NULL) {
c54de490	136	struct mips_hi16 *next;
4e6a05fe TS	137	unsigned long insn;
	138
	139	/*
	140	* The value for the HI16 had best be the same.
	141	*/
	142	if (v != l->value)
	143	goto out_danger;
	144
	145	/*
	146	* Do the HI16 relocation. Note that we actually don't
	147	* need to know anything about the LO16 itself, except
	148	* where to find the low 16 bits of the addend needed
	149	* by the LO16.
	150	*/
	151	insn = *l->addr;
	152	val = ((insn & 0xffff) << 16) + vallo;
	153	val += v;
	154
	155	/*
	156	* Account for the sign extension that will happen in
	157	* the low bits.
	158	*/
	159	val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
	160
	161	insn = (insn & ~0xffff) \| val;
	162	*l->addr = insn;
	163
	164	next = l->next;
	165	kfree(l);
	166	l = next;
	167	}
	168
861667dc	169	me->arch.r_mips_hi16_list = NULL;
4e6a05fe TS	170	}
	171
	172	/*
70342287	173	* Ok, we're done with the HI16 relocs. Now deal with the LO16.
4e6a05fe TS	174	*/
	175	val = v + vallo;
	176	insnlo = (insnlo & ~0xffff) \| (val & 0xffff);
	177	*location = insnlo;
	178
	179	return 0;
	180
	181	out_danger:
c54de490 RB	182	free_relocation_chain(l);
c54de490 RB	183	me->arch.r_mips_hi16_list = NULL;
d3cac35c	184
430d0b88	185	pr_err("module %s: dangerous R_MIPS_LO16 relocation\n", me->name);
4e6a05fe TS	186
	187	return -ENOEXEC;
	188	}
	189
430d0b88 PB	190	static int apply_r_mips_pc(struct module me, u32 location, u32 base,
430d0b88 PB	191	Elf_Addr v, unsigned int bits)
5d3c7925 PB	192	{
	193	unsigned long mask = GENMASK(bits - 1, 0);
	194	unsigned long se_bits;
	195	long offset;
	196
	197	if (v % 4) {
430d0b88	198	pr_err("module %s: dangerous R_MIPS_PC%u relocation\n",
5d3c7925 PB	199	me->name, bits);
	200	return -ENOEXEC;
	201	}
	202
430d0b88 PB	203	/* retrieve & sign extend implicit addend if any */
430d0b88 PB	204	offset = base & mask;
5d3c7925 PB	205	offset \|= (offset & BIT(bits - 1)) ? ~mask : 0;
	206
	207	offset += ((long)v - (long)location) >> 2;
	208
	209	/* check the sign bit onwards are identical - ie. we didn't overflow */
	210	se_bits = (offset & BIT(bits - 1)) ? ~0ul : 0;
	211	if ((offset & ~mask) != (se_bits & ~mask)) {
	212	pr_err("module %s: relocation overflow\n", me->name);
	213	return -ENOEXEC;
	214	}
	215
	216	location = (location & ~mask) \| (offset & mask);
	217
	218	return 0;
	219	}
	220
430d0b88 PB	221	static int apply_r_mips_pc16(struct module me, u32 location,
430d0b88 PB	222	u32 base, Elf_Addr v, bool rela)
5d3c7925	223	{
430d0b88	224	return apply_r_mips_pc(me, location, base, v, 16);
5d3c7925 PB	225	}
5d3c7925 PB	226
430d0b88 PB	227	static int apply_r_mips_pc21(struct module me, u32 location,
430d0b88 PB	228	u32 base, Elf_Addr v, bool rela)
5d3c7925	229	{
430d0b88	230	return apply_r_mips_pc(me, location, base, v, 21);
5d3c7925 PB	231	}
5d3c7925 PB	232
430d0b88 PB	233	static int apply_r_mips_pc26(struct module me, u32 location,
430d0b88 PB	234	u32 base, Elf_Addr v, bool rela)
5d3c7925	235	{
430d0b88	236	return apply_r_mips_pc(me, location, base, v, 26);
5d3c7925 PB	237	}
5d3c7925 PB	238
430d0b88 PB	239	static int apply_r_mips_64(struct module me, u32 location,
430d0b88 PB	240	u32 base, Elf_Addr v, bool rela)
5d3c7925	241	{
430d0b88 PB	242	if (WARN_ON(!rela))
	243	return -EINVAL;
	244
	245	(Elf_Addr )location = v;
	246
	247	return 0;
5d3c7925 PB	248	}
5d3c7925 PB	249
430d0b88 PB	250	static int apply_r_mips_higher(struct module me, u32 location,
430d0b88 PB	251	u32 base, Elf_Addr v, bool rela)
5d3c7925	252	{
430d0b88 PB	253	if (WARN_ON(!rela))
	254	return -EINVAL;
	255
	256	location = (location & 0xffff0000) \|
	257	((((long long)v + 0x80008000LL) >> 32) & 0xffff);
	258
	259	return 0;
5d3c7925 PB	260	}
5d3c7925 PB	261
430d0b88 PB	262	static int apply_r_mips_highest(struct module me, u32 location,
430d0b88 PB	263	u32 base, Elf_Addr v, bool rela)
5d3c7925	264	{
430d0b88 PB	265	if (WARN_ON(!rela))
	266	return -EINVAL;
	267
	268	location = (location & 0xffff0000) \|
	269	((((long long)v + 0x800080008000LL) >> 48) & 0xffff);
	270
	271	return 0;
5d3c7925 PB	272	}
5d3c7925 PB	273
430d0b88 PB	274	/**
	275	* reloc_handler() - Apply a particular relocation to a module
	276	* @me: the module to apply the reloc to
	277	* @location: the address at which the reloc is to be applied
	278	* @base: the existing value at location for REL-style; 0 for RELA-style
	279	* @v: the value of the reloc, with addend for RELA-style
	280	*
	281	* Each implemented reloc_handler function applies a particular type of
	282	* relocation to the module @me. Relocs that may be found in either REL or RELA
	283	* variants can be handled by making use of the @base & @v parameters which are
	284	* set to values which abstract the difference away from the particular reloc
	285	* implementations.
	286	*
	287	* Return: 0 upon success, else -ERRNO
	288	*/
	289	typedef int (reloc_handler)(struct module me, u32 *location,
	290	u32 base, Elf_Addr v, bool rela);
	291
	292	/* The handlers for known reloc types */
	293	static reloc_handler reloc_handlers[] = {
4e6a05fe	294	[R_MIPS_NONE] = apply_r_mips_none,
430d0b88 PB	295	[R_MIPS_32] = apply_r_mips_32,
	296	[R_MIPS_26] = apply_r_mips_26,
	297	[R_MIPS_HI16] = apply_r_mips_hi16,
	298	[R_MIPS_LO16] = apply_r_mips_lo16,
	299	[R_MIPS_PC16] = apply_r_mips_pc16,
	300	[R_MIPS_64] = apply_r_mips_64,
	301	[R_MIPS_HIGHER] = apply_r_mips_higher,
	302	[R_MIPS_HIGHEST] = apply_r_mips_highest,
	303	[R_MIPS_PC21_S2] = apply_r_mips_pc21,
	304	[R_MIPS_PC26_S2] = apply_r_mips_pc26,
4e6a05fe TS	305	};
4e6a05fe TS	306
430d0b88 PB	307	static int __apply_relocate(Elf_Shdr sechdrs, const char strtab,
	308	unsigned int symindex, unsigned int relsec,
	309	struct module *me, bool rela)
4e6a05fe	310	{
430d0b88 PB	311	union {
	312	Elf_Mips_Rel *rel;
	313	Elf_Mips_Rela *rela;
	314	} r;
	315	reloc_handler handler;
4e6a05fe	316	Elf_Sym *sym;
430d0b88	317	u32 *location, base;
04211a57	318	unsigned int i, type;
4e6a05fe	319	Elf_Addr v;
351b0940	320	int err = 0;
430d0b88	321	size_t reloc_sz;
4e6a05fe TS	322
	323	pr_debug("Applying relocate section %u to %u\n", relsec,
	324	sechdrs[relsec].sh_info);
	325
430d0b88 PB	326	r.rel = (void *)sechdrs[relsec].sh_addr;
430d0b88 PB	327	reloc_sz = rela ? sizeof(r.rela) : sizeof(r.rel);
861667dc	328	me->arch.r_mips_hi16_list = NULL;
430d0b88	329	for (i = 0; i < sechdrs[relsec].sh_size / reloc_sz; i++) {
4e6a05fe TS	330	/* This is where to make the change */
4e6a05fe TS	331	location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
430d0b88	332	+ r.rel->r_offset;
4e6a05fe TS	333	/* This is the symbol it is referring to */
4e6a05fe TS	334	sym = (Elf_Sym *)sechdrs[symindex].sh_addr
430d0b88	335	+ ELF_MIPS_R_SYM(*r.rel);
ba837d38	336	if (sym->st_value >= -MAX_ERRNO) {
f3bf07b9 AN	337	/* Ignore unresolved weak symbol */
	338	if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
	339	continue;
55d791f3 SH	340	pr_warn("%s: Unknown symbol %s\n",
55d791f3 SH	341	me->name, strtab + sym->st_name);
351b0940 PB	342	err = -ENOENT;
351b0940 PB	343	goto out;
4e6a05fe TS	344	}
4e6a05fe TS	345
430d0b88 PB	346	type = ELF_MIPS_R_TYPE(*r.rel);
	347	if (type < ARRAY_SIZE(reloc_handlers))
	348	handler = reloc_handlers[type];
04211a57 PB	349	else
04211a57 PB	350	handler = NULL;
4e6a05fe	351
04211a57 PB	352	if (!handler) {
	353	pr_err("%s: Unknown relocation type %u\n",
	354	me->name, type);
351b0940 PB	355	err = -EINVAL;
351b0940 PB	356	goto out;
04211a57 PB	357	}
04211a57 PB	358
430d0b88 PB	359	if (rela) {
	360	v = sym->st_value + r.rela->r_addend;
	361	base = 0;
	362	r.rela = &r.rela[1];
	363	} else {
	364	v = sym->st_value;
	365	base = *location;
	366	r.rel = &r.rel[1];
	367	}
	368
	369	err = handler(me, location, base, v, rela);
351b0940 PB	370	if (err)
351b0940 PB	371	goto out;
4e6a05fe TS	372	}
4e6a05fe TS	373
351b0940	374	out:
c54de490	375	/*
351b0940	376	* Normally the hi16 list should be deallocated at this point. A
c54de490	377	* malformed binary however could contain a series of R_MIPS_HI16
351b0940 PB	378	* relocations not followed by a R_MIPS_LO16 relocation, or if we hit
	379	* an error processing a reloc we might have gotten here before
	380	* reaching the R_MIPS_LO16. In either case, free up the list and
	381	* return an error.
c54de490 RB	382	*/
	383	if (me->arch.r_mips_hi16_list) {
	384	free_relocation_chain(me->arch.r_mips_hi16_list);
	385	me->arch.r_mips_hi16_list = NULL;
351b0940	386	err = err ?: -ENOEXEC;
c54de490 RB	387	}
c54de490 RB	388
351b0940	389	return err;
4e6a05fe TS	390	}
4e6a05fe TS	391
430d0b88 PB	392	int apply_relocate(Elf_Shdr sechdrs, const char strtab,
	393	unsigned int symindex, unsigned int relsec,
	394	struct module *me)
	395	{
	396	return __apply_relocate(sechdrs, strtab, symindex, relsec, me, false);
	397	}
	398
	399	#ifdef CONFIG_MODULES_USE_ELF_RELA
	400	int apply_relocate_add(Elf_Shdr sechdrs, const char strtab,
	401	unsigned int symindex, unsigned int relsec,
	402	struct module *me)
	403	{
	404	return __apply_relocate(sechdrs, strtab, symindex, relsec, me, true);
4e6a05fe	405	}
430d0b88	406	#endif /* CONFIG_MODULES_USE_ELF_RELA */
4e6a05fe	407
1da177e4 LT	408	/* Given an address, look for it in the module exception tables. */
	409	const struct exception_table_entry *search_module_dbetables(unsigned long addr)
	410	{
	411	unsigned long flags;
	412	const struct exception_table_entry *e = NULL;
	413	struct mod_arch_specific *dbe;
	414
	415	spin_lock_irqsave(&dbe_lock, flags);
	416	list_for_each_entry(dbe, &dbe_list, dbe_list) {
a94c33dd TM	417	e = search_extable(dbe->dbe_start,
a94c33dd TM	418	dbe->dbe_end - dbe->dbe_start, addr);
1da177e4 LT	419	if (e)
	420	break;
	421	}
	422	spin_unlock_irqrestore(&dbe_lock, flags);
	423
	424	/* Now, if we found one, we are running inside it now, hence
70342287	425	we cannot unload the module, hence no refcnt needed. */
1da177e4 LT	426	return e;
	427	}
	428
3a4fa0a2	429	/* Put in dbe list if necessary. */
1da177e4 LT	430	int module_finalize(const Elf_Ehdr *hdr,
	431	const Elf_Shdr *sechdrs,
	432	struct module *me)
	433	{
	434	const Elf_Shdr *s;
	435	char secstrings = (void )hdr + sechdrs[hdr->e_shstrndx].sh_offset;
	436
94bb0c1a DD	437	/* Make jump label nops. */
	438	jump_label_apply_nops(me);
	439
1da177e4 LT	440	INIT_LIST_HEAD(&me->arch.dbe_list);
	441	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
	442	if (strcmp("__dbe_table", secstrings + s->sh_name) != 0)
	443	continue;
	444	me->arch.dbe_start = (void *)s->sh_addr;
	445	me->arch.dbe_end = (void *)s->sh_addr + s->sh_size;
	446	spin_lock_irq(&dbe_lock);
	447	list_add(&me->arch.dbe_list, &dbe_list);
	448	spin_unlock_irq(&dbe_lock);
	449	}
	450	return 0;
	451	}
	452
	453	void module_arch_cleanup(struct module *mod)
	454	{
	455	spin_lock_irq(&dbe_lock);
	456	list_del(&mod->arch.dbe_list);
	457	spin_unlock_irq(&dbe_lock);
	458	}