summaryrefslogtreecommitdiffstats
path: root/arch/tile/kernel/module.c
blob: 001cbfa10ac6364a9136b9d4440bfe69730a08be (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
/*
 * 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 __tilegx__
# define Elf_Rela Elf64_Rela
# define ELF_R_SYM ELF64_R_SYM
# define ELF_R_TYPE ELF64_R_TYPE
#else
# define Elf_Rela Elf32_Rela
# define ELF_R_SYM ELF32_R_SYM
# define ELF_R_TYPE ELF32_R_TYPE
#endif

#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;
}