[deliverable/linux.git] / arch / x86 / kernel / module.c

/*  Kernel module help for x86.
    Copyright (C) 2001 Rusty Russell.

    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; either version 2 of the License, or
    (at your option) any later version.

    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.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
#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 <linux/bug.h>
#include <linux/mm.h>
#include <linux/gfp.h>

#include <asm/system.h>
#include <asm/page.h>
#include <asm/pgtable.h>

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

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 | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
				-1, __builtin_return_address(0));
}

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

/* We don't need anything special. */
int module_frob_arch_sections(Elf_Ehdr *hdr,
			      Elf_Shdr *sechdrs,
			      char *secstrings,
			      struct module *mod)
{
	return 0;
}

#ifdef CONFIG_X86_32
int apply_relocate(Elf32_Shdr *sechdrs,
		   const char *strtab,
		   unsigned int symindex,
		   unsigned int relsec,
		   struct module *me)
{
	unsigned int i;
	Elf32_Rel *rel = (void *)sechdrs[relsec].sh_addr;
	Elf32_Sym *sym;
	uint32_t *location;

	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 = (Elf32_Sym *)sechdrs[symindex].sh_addr
			+ ELF32_R_SYM(rel[i].r_info);

		switch (ELF32_R_TYPE(rel[i].r_info)) {
		case R_386_32:
			/* We add the value into the location given */
			*location += sym->st_value;
			break;
		case R_386_PC32:
			/* Add the value, subtract its postition */
			*location += sym->st_value - (uint32_t)location;
			break;
		default:
			printk(KERN_ERR "module %s: Unknown relocation: %u\n",
			       me->name, ELF32_R_TYPE(rel[i].r_info));
			return -ENOEXEC;
		}
	}
	return 0;
}

int apply_relocate_add(Elf32_Shdr *sechdrs,
		       const char *strtab,
		       unsigned int symindex,
		       unsigned int relsec,
		       struct module *me)
{
	printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
	       me->name);
	return -ENOEXEC;
}
#else /*X86_64*/
int apply_relocate_add(Elf64_Shdr *sechdrs,
		   const char *strtab,
		   unsigned int symindex,
		   unsigned int relsec,
		   struct module *me)
{
	unsigned int i;
	Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
	Elf64_Sym *sym;
	void *loc;
	u64 val;

	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 */
		loc = (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 = (Elf64_Sym *)sechdrs[symindex].sh_addr
			+ ELF64_R_SYM(rel[i].r_info);

		DEBUGP("type %d st_value %Lx r_addend %Lx loc %Lx\n",
			(int)ELF64_R_TYPE(rel[i].r_info),
			sym->st_value, rel[i].r_addend, (u64)loc);

		val = sym->st_value + rel[i].r_addend;

		switch (ELF64_R_TYPE(rel[i].r_info)) {
		case R_X86_64_NONE:
			break;
		case R_X86_64_64:
			*(u64 *)loc = val;
			break;
		case R_X86_64_32:
			*(u32 *)loc = val;
			if (val != *(u32 *)loc)
				goto overflow;
			break;
		case R_X86_64_32S:
			*(s32 *)loc = val;
			if ((s64)val != *(s32 *)loc)
				goto overflow;
			break;
		case R_X86_64_PC32:
			val -= (u64)loc;
			*(u32 *)loc = val;
#if 0
			if ((s64)val != *(s32 *)loc)
				goto overflow;
#endif
			break;
		default:
			printk(KERN_ERR "module %s: Unknown rela relocation: %llu\n",
			       me->name, ELF64_R_TYPE(rel[i].r_info));
			return -ENOEXEC;
		}
	}
	return 0;

overflow:
	printk(KERN_ERR "overflow in relocation type %d val %Lx\n",
	       (int)ELF64_R_TYPE(rel[i].r_info), val);
	printk(KERN_ERR "`%s' likely not compiled with -mcmodel=kernel\n",
	       me->name);
	return -ENOEXEC;
}

int apply_relocate(Elf_Shdr *sechdrs,
		   const char *strtab,
		   unsigned int symindex,
		   unsigned int relsec,
		   struct module *me)
{
	printk(KERN_ERR "non add relocation not supported\n");
	return -ENOSYS;
}

#endif

int module_finalize(const Elf_Ehdr *hdr,
		    const Elf_Shdr *sechdrs,
		    struct module *me)
{
	const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL,
		*para = NULL;
	char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;

	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
		if (!strcmp(".text", secstrings + s->sh_name))
			text = s;
		if (!strcmp(".altinstructions", secstrings + s->sh_name))
			alt = s;
		if (!strcmp(".smp_locks", secstrings + s->sh_name))
			locks = s;
		if (!strcmp(".parainstructions", secstrings + s->sh_name))
			para = s;
	}

	if (alt) {
		/* patch .altinstructions */
		void *aseg = (void *)alt->sh_addr;
		apply_alternatives(aseg, aseg + alt->sh_size);
	}
	if (locks && text) {
		void *lseg = (void *)locks->sh_addr;
		void *tseg = (void *)text->sh_addr;
		alternatives_smp_module_add(me, me->name,
					    lseg, lseg + locks->sh_size,
					    tseg, tseg + text->sh_size);
	}

	if (para) {
		void *pseg = (void *)para->sh_addr;
		apply_paravirt(pseg, pseg + para->sh_size);
	}

	/* make jump label nops */
	jump_label_apply_nops(me);

	return 0;
}

void module_arch_cleanup(struct module *mod)
{
	alternatives_smp_module_del(mod);
}
Commit	Line	Data
2d5bf28f AW	1	/* Kernel module help for x86.
	2	Copyright (C) 2001 Rusty Russell.
	3
	4	This program is free software; you can redistribute it and/or modify
	5	it under the terms of the GNU General Public License as published by
	6	the Free Software Foundation; either version 2 of the License, or
	7	(at your option) any later version.
	8
	9	This program is distributed in the hope that it will be useful,
	10	but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	GNU General Public License for more details.
	13
	14	You should have received a copy of the GNU General Public License
	15	along with this program; if not, write to the Free Software
	16	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	17	*/
	18	#include <linux/moduleloader.h>
	19	#include <linux/elf.h>
	20	#include <linux/vmalloc.h>
	21	#include <linux/fs.h>
	22	#include <linux/string.h>
	23	#include <linux/kernel.h>
	24	#include <linux/bug.h>
	25	#include <linux/mm.h>
5a0e3ad6	26	#include <linux/gfp.h>
2d5bf28f AW	27
	28	#include <asm/system.h>
	29	#include <asm/page.h>
	30	#include <asm/pgtable.h>
	31
	32	#if 0
	33	#define DEBUGP printk
	34	#else
	35	#define DEBUGP(fmt...)
	36	#endif
	37
0fdc83b9 AW	38	void *module_alloc(unsigned long size)
0fdc83b9 AW	39	{
d0a21265	40	if (PAGE_ALIGN(size) > MODULES_LEN)
0fdc83b9	41	return NULL;
d0a21265 DR	42	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
	43	GFP_KERNEL \| __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
	44	-1, __builtin_return_address(0));
0fdc83b9	45	}
0fdc83b9	46
2d5bf28f AW	47	/* Free memory returned from module_alloc */
	48	void module_free(struct module mod, void module_region)
	49	{
	50	vfree(module_region);
2d5bf28f AW	51	}
	52
	53	/* We don't need anything special. */
	54	int module_frob_arch_sections(Elf_Ehdr *hdr,
	55	Elf_Shdr *sechdrs,
	56	char *secstrings,
	57	struct module *mod)
	58	{
	59	return 0;
	60	}
	61
0fdc83b9 AW	62	#ifdef CONFIG_X86_32
	63	int apply_relocate(Elf32_Shdr *sechdrs,
	64	const char *strtab,
	65	unsigned int symindex,
	66	unsigned int relsec,
	67	struct module *me)
	68	{
	69	unsigned int i;
	70	Elf32_Rel rel = (void )sechdrs[relsec].sh_addr;
	71	Elf32_Sym *sym;
	72	uint32_t *location;
	73
	74	DEBUGP("Applying relocate section %u to %u\n", relsec,
	75	sechdrs[relsec].sh_info);
	76	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
	77	/* This is where to make the change */
	78	location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
	79	+ rel[i].r_offset;
	80	/* This is the symbol it is referring to. Note that all
	81	undefined symbols have been resolved. */
	82	sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
	83	+ ELF32_R_SYM(rel[i].r_info);
	84
	85	switch (ELF32_R_TYPE(rel[i].r_info)) {
	86	case R_386_32:
	87	/* We add the value into the location given */
	88	*location += sym->st_value;
	89	break;
	90	case R_386_PC32:
	91	/* Add the value, subtract its postition */
	92	*location += sym->st_value - (uint32_t)location;
	93	break;
	94	default:
	95	printk(KERN_ERR "module %s: Unknown relocation: %u\n",
	96	me->name, ELF32_R_TYPE(rel[i].r_info));
	97	return -ENOEXEC;
	98	}
	99	}
	100	return 0;
	101	}
	102
	103	int apply_relocate_add(Elf32_Shdr *sechdrs,
	104	const char *strtab,
	105	unsigned int symindex,
	106	unsigned int relsec,
	107	struct module *me)
	108	{
	109	printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
	110	me->name);
	111	return -ENOEXEC;
	112	}
	113	#else /X86_64/
	114	int apply_relocate_add(Elf64_Shdr *sechdrs,
	115	const char *strtab,
	116	unsigned int symindex,
	117	unsigned int relsec,
	118	struct module *me)
	119	{
	120	unsigned int i;
	121	Elf64_Rela rel = (void )sechdrs[relsec].sh_addr;
	122	Elf64_Sym *sym;
	123	void *loc;
	124	u64 val;
	125
126	DEBUGP("Applying relocate section %u to %u\n", relsec,
127	sechdrs[relsec].sh_info);
128	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
129	/* This is where to make the change */
130	loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
131	+ rel[i].r_offset;
132
133	/* This is the symbol it is referring to. Note that all
134	undefined symbols have been resolved. */
135	sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
136	+ ELF64_R_SYM(rel[i].r_info);
137
138	DEBUGP("type %d st_value %Lx r_addend %Lx loc %Lx\n",
139	(int)ELF64_R_TYPE(rel[i].r_info),
140	sym->st_value, rel[i].r_addend, (u64)loc);
141
142	val = sym->st_value + rel[i].r_addend;
143
144	switch (ELF64_R_TYPE(rel[i].r_info)) {
145	case R_X86_64_NONE:
146	break;
147	case R_X86_64_64:
148	(u64 )loc = val;
149	break;
150	case R_X86_64_32:
151	(u32 )loc = val;
152	if (val != (u32 )loc)
153	goto overflow;
154	break;
155	case R_X86_64_32S:
156	(s32 )loc = val;
157	if ((s64)val != (s32 )loc)
158	goto overflow;
159	break;
160	case R_X86_64_PC32:
161	val -= (u64)loc;
162	(u32 )loc = val;
163	#if 0
164	if ((s64)val != (s32 )loc)
165	goto overflow;
166	#endif
167	break;
168	default:
169	printk(KERN_ERR "module %s: Unknown rela relocation: %llu\n",
170	me->name, ELF64_R_TYPE(rel[i].r_info));
171	return -ENOEXEC;
172	}
173	}
174	return 0;
175
176	overflow:
177	printk(KERN_ERR "overflow in relocation type %d val %Lx\n",
178	(int)ELF64_R_TYPE(rel[i].r_info), val);
179	printk(KERN_ERR "`%s' likely not compiled with -mcmodel=kernel\n",
180	me->name);
181	return -ENOEXEC;
182	}
183
184	int apply_relocate(Elf_Shdr *sechdrs,
185	const char *strtab,
186	unsigned int symindex,
187	unsigned int relsec,
188	struct module *me)
189	{
190	printk(KERN_ERR "non add relocation not supported\n");
191	return -ENOSYS;
192	}
193
194	#endif
195
2d5bf28f AW	196	int module_finalize(const Elf_Ehdr *hdr,
	197	const Elf_Shdr *sechdrs,
	198	struct module *me)
	199	{
	200	const Elf_Shdr s, text = NULL, alt = NULL, locks = NULL,
	201	*para = NULL;
	202	char secstrings = (void )hdr + sechdrs[hdr->e_shstrndx].sh_offset;
	203
	204	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
	205	if (!strcmp(".text", secstrings + s->sh_name))
	206	text = s;
	207	if (!strcmp(".altinstructions", secstrings + s->sh_name))
	208	alt = s;
	209	if (!strcmp(".smp_locks", secstrings + s->sh_name))
	210	locks = s;
	211	if (!strcmp(".parainstructions", secstrings + s->sh_name))
	212	para = s;
	213	}
	214
	215	if (alt) {
	216	/* patch .altinstructions */
	217	void aseg = (void )alt->sh_addr;
	218	apply_alternatives(aseg, aseg + alt->sh_size);
	219	}
	220	if (locks && text) {
	221	void lseg = (void )locks->sh_addr;
	222	void tseg = (void )text->sh_addr;
	223	alternatives_smp_module_add(me, me->name,
	224	lseg, lseg + locks->sh_size,
	225	tseg, tseg + text->sh_size);
	226	}
	227
	228	if (para) {
	229	void pseg = (void )para->sh_addr;
	230	apply_paravirt(pseg, pseg + para->sh_size);
	231	}
	232
d9f5ab7b JB	233	/* make jump label nops */
	234	jump_label_apply_nops(me);
	235
5336377d	236	return 0;
2d5bf28f AW	237	}
	238
	239	void module_arch_cleanup(struct module *mod)
	240	{
	241	alternatives_smp_module_del(mod);
2d5bf28f	242	}