[net-next-2.6.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)
{
	struct vm_struct *area;

	if (!size)
		return NULL;
	size = PAGE_ALIGN(size);
	if (size > MODULES_LEN)
		return NULL;

	area = __get_vm_area(size, VM_ALLOC, MODULES_VADDR, MODULES_END);
	if (!area)
		return NULL;

	return __vmalloc_area(area, GFP_KERNEL | __GFP_HIGHMEM,
					PAGE_KERNEL_EXEC);
}

/* 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)
	39	{
	40	struct vm_struct *area;
	41
	42	if (!size)
	43	return NULL;
	44	size = PAGE_ALIGN(size);
	45	if (size > MODULES_LEN)
	46	return NULL;
	47
	48	area = __get_vm_area(size, VM_ALLOC, MODULES_VADDR, MODULES_END);
	49	if (!area)
	50	return NULL;
	51
c398df30 AW	52	return __vmalloc_area(area, GFP_KERNEL \| __GFP_HIGHMEM,
c398df30 AW	53	PAGE_KERNEL_EXEC);
0fdc83b9	54	}
0fdc83b9	55
2d5bf28f AW	56	/* Free memory returned from module_alloc */
	57	void module_free(struct module mod, void module_region)
	58	{
	59	vfree(module_region);
2d5bf28f AW	60	}
	61
	62	/* We don't need anything special. */
	63	int module_frob_arch_sections(Elf_Ehdr *hdr,
	64	Elf_Shdr *sechdrs,
	65	char *secstrings,
	66	struct module *mod)
	67	{
	68	return 0;
	69	}
	70
0fdc83b9 AW	71	#ifdef CONFIG_X86_32
	72	int apply_relocate(Elf32_Shdr *sechdrs,
	73	const char *strtab,
	74	unsigned int symindex,
	75	unsigned int relsec,
	76	struct module *me)
	77	{
	78	unsigned int i;
	79	Elf32_Rel rel = (void )sechdrs[relsec].sh_addr;
	80	Elf32_Sym *sym;
	81	uint32_t *location;
	82
	83	DEBUGP("Applying relocate section %u to %u\n", relsec,
	84	sechdrs[relsec].sh_info);
	85	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
	86	/* This is where to make the change */
	87	location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
	88	+ rel[i].r_offset;
	89	/* This is the symbol it is referring to. Note that all
	90	undefined symbols have been resolved. */
	91	sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
	92	+ ELF32_R_SYM(rel[i].r_info);
	93
	94	switch (ELF32_R_TYPE(rel[i].r_info)) {
	95	case R_386_32:
	96	/* We add the value into the location given */
	97	*location += sym->st_value;
	98	break;
	99	case R_386_PC32:
	100	/* Add the value, subtract its postition */
	101	*location += sym->st_value - (uint32_t)location;
	102	break;
	103	default:
	104	printk(KERN_ERR "module %s: Unknown relocation: %u\n",
	105	me->name, ELF32_R_TYPE(rel[i].r_info));
	106	return -ENOEXEC;
	107	}
	108	}
	109	return 0;
	110	}
	111
	112	int apply_relocate_add(Elf32_Shdr *sechdrs,
	113	const char *strtab,
	114	unsigned int symindex,
	115	unsigned int relsec,
	116	struct module *me)
	117	{
	118	printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
	119	me->name);
	120	return -ENOEXEC;
	121	}
	122	#else /X86_64/
	123	int apply_relocate_add(Elf64_Shdr *sechdrs,
	124	const char *strtab,
	125	unsigned int symindex,
	126	unsigned int relsec,
	127	struct module *me)
	128	{
	129	unsigned int i;
	130	Elf64_Rela rel = (void )sechdrs[relsec].sh_addr;
	131	Elf64_Sym *sym;
	132	void *loc;
	133	u64 val;
	134
135	DEBUGP("Applying relocate section %u to %u\n", relsec,
136	sechdrs[relsec].sh_info);
137	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
138	/* This is where to make the change */
139	loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
140	+ rel[i].r_offset;
141
142	/* This is the symbol it is referring to. Note that all
143	undefined symbols have been resolved. */
144	sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
145	+ ELF64_R_SYM(rel[i].r_info);
146
147	DEBUGP("type %d st_value %Lx r_addend %Lx loc %Lx\n",
148	(int)ELF64_R_TYPE(rel[i].r_info),
149	sym->st_value, rel[i].r_addend, (u64)loc);
150
151	val = sym->st_value + rel[i].r_addend;
152
153	switch (ELF64_R_TYPE(rel[i].r_info)) {
154	case R_X86_64_NONE:
155	break;
156	case R_X86_64_64:
157	(u64 )loc = val;
158	break;
159	case R_X86_64_32:
160	(u32 )loc = val;
161	if (val != (u32 )loc)
162	goto overflow;
163	break;
164	case R_X86_64_32S:
165	(s32 )loc = val;
166	if ((s64)val != (s32 )loc)
167	goto overflow;
168	break;
169	case R_X86_64_PC32:
170	val -= (u64)loc;
171	(u32 )loc = val;
172	#if 0
173	if ((s64)val != (s32 )loc)
174	goto overflow;
175	#endif
176	break;
177	default:
178	printk(KERN_ERR "module %s: Unknown rela relocation: %llu\n",
179	me->name, ELF64_R_TYPE(rel[i].r_info));
180	return -ENOEXEC;
181	}
182	}
183	return 0;
184
185	overflow:
186	printk(KERN_ERR "overflow in relocation type %d val %Lx\n",
187	(int)ELF64_R_TYPE(rel[i].r_info), val);
188	printk(KERN_ERR "`%s' likely not compiled with -mcmodel=kernel\n",
189	me->name);
190	return -ENOEXEC;
191	}
192
193	int apply_relocate(Elf_Shdr *sechdrs,
194	const char *strtab,
195	unsigned int symindex,
196	unsigned int relsec,
197	struct module *me)
198	{
199	printk(KERN_ERR "non add relocation not supported\n");
200	return -ENOSYS;
201	}
202
203	#endif
204
2d5bf28f AW	205	int module_finalize(const Elf_Ehdr *hdr,
	206	const Elf_Shdr *sechdrs,
	207	struct module *me)
	208	{
	209	const Elf_Shdr s, text = NULL, alt = NULL, locks = NULL,
	210	*para = NULL;
	211	char secstrings = (void )hdr + sechdrs[hdr->e_shstrndx].sh_offset;
	212
	213	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
	214	if (!strcmp(".text", secstrings + s->sh_name))
	215	text = s;
	216	if (!strcmp(".altinstructions", secstrings + s->sh_name))
	217	alt = s;
	218	if (!strcmp(".smp_locks", secstrings + s->sh_name))
	219	locks = s;
	220	if (!strcmp(".parainstructions", secstrings + s->sh_name))
	221	para = s;
	222	}
	223
	224	if (alt) {
	225	/* patch .altinstructions */
	226	void aseg = (void )alt->sh_addr;
	227	apply_alternatives(aseg, aseg + alt->sh_size);
	228	}
	229	if (locks && text) {
	230	void lseg = (void )locks->sh_addr;
	231	void tseg = (void )text->sh_addr;
	232	alternatives_smp_module_add(me, me->name,
	233	lseg, lseg + locks->sh_size,
	234	tseg, tseg + text->sh_size);
	235	}
	236
	237	if (para) {
	238	void pseg = (void )para->sh_addr;
	239	apply_paravirt(pseg, pseg + para->sh_size);
	240	}
	241
d9f5ab7b JB	242	/* make jump label nops */
	243	jump_label_apply_nops(me);
	244
5336377d	245	return 0;
2d5bf28f AW	246	}
	247
	248	void module_arch_cleanup(struct module *mod)
	249	{
	250	alternatives_smp_module_del(mod);
2d5bf28f	251	}