[deliverable/linux.git] / arch / tile / kernel / module.c

/*
 * Copyright 2010 Tilera Corporation. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation, version 2.
 *
 *   This program is distributed in the hope that it will be useful, but
 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 *   NON INFRINGEMENT.  See the GNU General Public License for
 *   more details.
 *
 * Based on i386 version, copyright (C) 2001 Rusty Russell.
 */

#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <asm/pgtable.h>
#include <asm/homecache.h>
#include <arch/opcode.h>

#ifdef MODULE_DEBUG
#define DEBUGP printk
#else
#define DEBUGP(fmt...)
#endif

/*
 * Allocate some address space in the range MEM_MODULE_START to
 * MEM_MODULE_END and populate it with memory.
 */
void *module_alloc(unsigned long size)
{
	struct page **pages;
	pgprot_t prot_rwx = __pgprot(_PAGE_KERNEL | _PAGE_KERNEL_EXEC);
	struct vm_struct *area;
	int i = 0;
	int npages;

	if (size == 0)
		return NULL;
	npages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
	pages = kmalloc(npages * sizeof(struct page *), GFP_KERNEL);
	if (pages == NULL)
		return NULL;
	for (; i < npages; ++i) {
		pages[i] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
		if (!pages[i])
			goto error;
	}

	area = __get_vm_area(size, VM_ALLOC, MEM_MODULE_START, MEM_MODULE_END);
	if (!area)
		goto error;
	area->nr_pages = npages;
	area->pages = pages;

	if (map_vm_area(area, prot_rwx, &pages)) {
		vunmap(area->addr);
		goto error;
	}

	return area->addr;

error:
	while (--i >= 0)
		__free_page(pages[i]);
	kfree(pages);
	return NULL;
}


/* Free memory returned from module_alloc */
void module_free(struct module *mod, void *module_region)
{
	vfree(module_region);

	/* Globally flush the L1 icache. */
	flush_remote(0, HV_FLUSH_EVICT_L1I, cpu_online_mask,
		     0, 0, 0, NULL, NULL, 0);

	/*
	 * FIXME: If module_region == mod->module_init, trim exception
	 * table entries.
	 */
}

#ifdef __tilegx__
/*
 * Validate that the high 16 bits of "value" is just the sign-extension of
 * the low 48 bits.
 */
static int validate_hw2_last(long value, struct module *me)
{
	if (((value << 16) >> 16) != value) {
		pr_warning("module %s: Out of range HW2_LAST value %#lx\n",
			   me->name, value);
		return 0;
	}
	return 1;
}

/*
 * Validate that "value" isn't too big to hold in a JumpOff relocation.
 */
static int validate_jumpoff(long value)
{
	/* Determine size of jump offset. */
	int shift = __builtin_clzl(get_JumpOff_X1(create_JumpOff_X1(-1)));

	/* Check to see if it fits into the relocation slot. */
	long f = get_JumpOff_X1(create_JumpOff_X1(value));
	f = (f << shift) >> shift;

	return f == value;
}
#endif

int apply_relocate_add(Elf_Shdr *sechdrs,
		       const char *strtab,
		       unsigned int symindex,
		       unsigned int relsec,
		       struct module *me)
{
	unsigned int i;
	Elf_Rela *rel = (void *)sechdrs[relsec].sh_addr;
	Elf_Sym *sym;
	u64 *location;
	unsigned long value;

	DEBUGP("Applying relocate section %u to %u\n", relsec,
	       sechdrs[relsec].sh_info);
	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
		/* This is where to make the change */
		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
			+ rel[i].r_offset;
		/*
		 * This is the symbol it is referring to.
		 * Note that all undefined symbols have been resolved.
		 */
		sym = (Elf_Sym *)sechdrs[symindex].sh_addr
			+ ELF_R_SYM(rel[i].r_info);
		value = sym->st_value + rel[i].r_addend;

		switch (ELF_R_TYPE(rel[i].r_info)) {

#ifdef __LITTLE_ENDIAN
# define MUNGE(func) \
	(*location = ((*location & ~func(-1)) | func(value)))
#else
/*
 * Instructions are always little-endian, so when we read them as data,
 * we have to swap them around before and after modifying them.
 */
# define MUNGE(func) \
	(*location = swab64((swab64(*location) & ~func(-1)) | func(value)))
#endif

#ifndef __tilegx__
		case R_TILE_32:
			*(uint32_t *)location = value;
			break;
		case R_TILE_IMM16_X0_HA:
			value = (value + 0x8000) >> 16;
			/*FALLTHROUGH*/
		case R_TILE_IMM16_X0_LO:
			MUNGE(create_Imm16_X0);
			break;
		case R_TILE_IMM16_X1_HA:
			value = (value + 0x8000) >> 16;
			/*FALLTHROUGH*/
		case R_TILE_IMM16_X1_LO:
			MUNGE(create_Imm16_X1);
			break;
		case R_TILE_JOFFLONG_X1:
			value -= (unsigned long) location;  /* pc-relative */
			value = (long) value >> 3;     /* count by instrs */
			MUNGE(create_JOffLong_X1);
			break;
#else
		case R_TILEGX_64:
			*location = value;
			break;
		case R_TILEGX_IMM16_X0_HW2_LAST:
			if (!validate_hw2_last(value, me))
				return -ENOEXEC;
			value >>= 16;
			/*FALLTHROUGH*/
		case R_TILEGX_IMM16_X0_HW1:
			value >>= 16;
			/*FALLTHROUGH*/
		case R_TILEGX_IMM16_X0_HW0:
			MUNGE(create_Imm16_X0);
			break;
		case R_TILEGX_IMM16_X1_HW2_LAST:
			if (!validate_hw2_last(value, me))
				return -ENOEXEC;
			value >>= 16;
			/*FALLTHROUGH*/
		case R_TILEGX_IMM16_X1_HW1:
			value >>= 16;
			/*FALLTHROUGH*/
		case R_TILEGX_IMM16_X1_HW0:
			MUNGE(create_Imm16_X1);
			break;
		case R_TILEGX_JUMPOFF_X1:
			value -= (unsigned long) location;  /* pc-relative */
			value = (long) value >> 3;     /* count by instrs */
			if (!validate_jumpoff(value)) {
				pr_warning("module %s: Out of range jump to"
					   " %#llx at %#llx (%p)\n", me->name,
					   sym->st_value + rel[i].r_addend,
					   rel[i].r_offset, location);
				return -ENOEXEC;
			}
			MUNGE(create_JumpOff_X1);
			break;
#endif

#undef MUNGE

		default:
			pr_err("module %s: Unknown relocation: %d\n",
			       me->name, (int) ELF_R_TYPE(rel[i].r_info));
			return -ENOEXEC;
		}
	}
	return 0;
}
Commit	Line	Data
867e359b CM	1	/*
	2	* Copyright 2010 Tilera Corporation. All Rights Reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation, version 2.
	7	*
	8	* This program is distributed in the hope that it will be useful, but
	9	* WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
	11	* NON INFRINGEMENT. See the GNU General Public License for
	12	* more details.
	13	*
	14	* Based on i386 version, copyright (C) 2001 Rusty Russell.
	15	*/
	16
	17	#include <linux/moduleloader.h>
	18	#include <linux/elf.h>
	19	#include <linux/vmalloc.h>
	20	#include <linux/fs.h>
	21	#include <linux/string.h>
	22	#include <linux/kernel.h>
867e359b	23	#include <asm/pgtable.h>
229f4df1	24	#include <asm/homecache.h>
eb7c792d	25	#include <arch/opcode.h>
867e359b	26
867e359b CM	27	#ifdef MODULE_DEBUG
	28	#define DEBUGP printk
	29	#else
	30	#define DEBUGP(fmt...)
	31	#endif
	32
	33	/*
	34	* Allocate some address space in the range MEM_MODULE_START to
	35	* MEM_MODULE_END and populate it with memory.
	36	*/
	37	void *module_alloc(unsigned long size)
	38	{
	39	struct page **pages;
	40	pgprot_t prot_rwx = __pgprot(_PAGE_KERNEL \| _PAGE_KERNEL_EXEC);
	41	struct vm_struct *area;
	42	int i = 0;
	43	int npages;
	44
	45	if (size == 0)
	46	return NULL;
	47	npages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
	48	pages = kmalloc(npages * sizeof(struct page *), GFP_KERNEL);
	49	if (pages == NULL)
	50	return NULL;
	51	for (; i < npages; ++i) {
	52	pages[i] = alloc_page(GFP_KERNEL \| __GFP_HIGHMEM);
	53	if (!pages[i])
	54	goto error;
	55	}
	56
	57	area = __get_vm_area(size, VM_ALLOC, MEM_MODULE_START, MEM_MODULE_END);
	58	if (!area)
	59	goto error;
5f220704 CM	60	area->nr_pages = npages;
5f220704 CM	61	area->pages = pages;
867e359b CM	62
	63	if (map_vm_area(area, prot_rwx, &pages)) {
	64	vunmap(area->addr);
	65	goto error;
	66	}
	67
	68	return area->addr;
	69
	70	error:
	71	while (--i >= 0)
	72	__free_page(pages[i]);
	73	kfree(pages);
	74	return NULL;
	75	}
	76
	77
	78	/* Free memory returned from module_alloc */
	79	void module_free(struct module mod, void module_region)
	80	{
	81	vfree(module_region);
229f4df1 CM	82
	83	/* Globally flush the L1 icache. */
	84	flush_remote(0, HV_FLUSH_EVICT_L1I, cpu_online_mask,
	85	0, 0, 0, NULL, NULL, 0);
	86
867e359b	87	/*
229f4df1	88	* FIXME: If module_region == mod->module_init, trim exception
867e359b CM	89	* table entries.
	90	*/
	91	}
	92
867e359b CM	93	#ifdef __tilegx__
	94	/*
	95	* Validate that the high 16 bits of "value" is just the sign-extension of
	96	* the low 48 bits.
	97	*/
	98	static int validate_hw2_last(long value, struct module *me)
	99	{
	100	if (((value << 16) >> 16) != value) {
0707ad30 CM	101	pr_warning("module %s: Out of range HW2_LAST value %#lx\n",
0707ad30 CM	102	me->name, value);
867e359b CM	103	return 0;
	104	}
	105	return 1;
	106	}
	107
	108	/*
	109	* Validate that "value" isn't too big to hold in a JumpOff relocation.
	110	*/
	111	static int validate_jumpoff(long value)
	112	{
	113	/* Determine size of jump offset. */
	114	int shift = __builtin_clzl(get_JumpOff_X1(create_JumpOff_X1(-1)));
	115
	116	/* Check to see if it fits into the relocation slot. */
	117	long f = get_JumpOff_X1(create_JumpOff_X1(value));
	118	f = (f << shift) >> shift;
	119
	120	return f == value;
	121	}
	122	#endif
	123
	124	int apply_relocate_add(Elf_Shdr *sechdrs,
	125	const char *strtab,
	126	unsigned int symindex,
	127	unsigned int relsec,
	128	struct module *me)
	129	{
	130	unsigned int i;
	131	Elf_Rela rel = (void )sechdrs[relsec].sh_addr;
	132	Elf_Sym *sym;
	133	u64 *location;
	134	unsigned long value;
	135
	136	DEBUGP("Applying relocate section %u to %u\n", relsec,
	137	sechdrs[relsec].sh_info);
	138	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
	139	/* This is where to make the change */
	140	location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
	141	+ rel[i].r_offset;
	142	/*
	143	* This is the symbol it is referring to.
	144	* Note that all undefined symbols have been resolved.
	145	*/
	146	sym = (Elf_Sym *)sechdrs[symindex].sh_addr
	147	+ ELF_R_SYM(rel[i].r_info);
	148	value = sym->st_value + rel[i].r_addend;
	149
	150	switch (ELF_R_TYPE(rel[i].r_info)) {
	151
1efea40d CM	152	#ifdef __LITTLE_ENDIAN
	153	# define MUNGE(func) \
	154	(location = ((location & ~func(-1)) \| func(value)))
	155	#else
	156	/*
	157	* Instructions are always little-endian, so when we read them as data,
	158	* we have to swap them around before and after modifying them.
	159	*/
	160	# define MUNGE(func) \
	161	(location = swab64((swab64(location) & ~func(-1)) \| func(value)))
	162	#endif
867e359b CM	163
	164	#ifndef __tilegx__
	165	case R_TILE_32:
	166	(uint32_t )location = value;
	167	break;
	168	case R_TILE_IMM16_X0_HA:
	169	value = (value + 0x8000) >> 16;
	170	/FALLTHROUGH/
	171	case R_TILE_IMM16_X0_LO:
	172	MUNGE(create_Imm16_X0);
	173	break;
	174	case R_TILE_IMM16_X1_HA:
	175	value = (value + 0x8000) >> 16;
	176	/FALLTHROUGH/
	177	case R_TILE_IMM16_X1_LO:
	178	MUNGE(create_Imm16_X1);
	179	break;
	180	case R_TILE_JOFFLONG_X1:
	181	value -= (unsigned long) location; /* pc-relative */
	182	value = (long) value >> 3; /* count by instrs */
	183	MUNGE(create_JOffLong_X1);
	184	break;
	185	#else
	186	case R_TILEGX_64:
	187	*location = value;
	188	break;
	189	case R_TILEGX_IMM16_X0_HW2_LAST:
	190	if (!validate_hw2_last(value, me))
	191	return -ENOEXEC;
	192	value >>= 16;
	193	/FALLTHROUGH/
	194	case R_TILEGX_IMM16_X0_HW1:
	195	value >>= 16;
	196	/FALLTHROUGH/
	197	case R_TILEGX_IMM16_X0_HW0:
	198	MUNGE(create_Imm16_X0);
	199	break;
	200	case R_TILEGX_IMM16_X1_HW2_LAST:
	201	if (!validate_hw2_last(value, me))
	202	return -ENOEXEC;
	203	value >>= 16;
	204	/FALLTHROUGH/
	205	case R_TILEGX_IMM16_X1_HW1:
	206	value >>= 16;
	207	/FALLTHROUGH/
	208	case R_TILEGX_IMM16_X1_HW0:
	209	MUNGE(create_Imm16_X1);
	210	break;
	211	case R_TILEGX_JUMPOFF_X1:
	212	value -= (unsigned long) location; /* pc-relative */
	213	value = (long) value >> 3; /* count by instrs */
	214	if (!validate_jumpoff(value)) {
0707ad30 CM	215	pr_warning("module %s: Out of range jump to"
	216	" %#llx at %#llx (%p)\n", me->name,
	217	sym->st_value + rel[i].r_addend,
	218	rel[i].r_offset, location);
867e359b CM	219	return -ENOEXEC;
	220	}
	221	MUNGE(create_JumpOff_X1);
	222	break;
	223	#endif
	224
	225	#undef MUNGE
	226
	227	default:
0707ad30	228	pr_err("module %s: Unknown relocation: %d\n",
867e359b CM	229	me->name, (int) ELF_R_TYPE(rel[i].r_info));
	230	return -ENOEXEC;
	231	}
	232	}
	233	return 0;
	234	}