[mirror_ubuntu-artful-kernel.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
*/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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 <linux/jump_label.h>

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

#if 0
#define DEBUGP(fmt, ...)				\
	printk(KERN_DEBUG fmt, ##__VA_ARGS__)
#else
#define DEBUGP(fmt, ...)				\
do {							\
	if (0)						\
		printk(KERN_DEBUG fmt, ##__VA_ARGS__);	\
} while (0)
#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));
}

#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 position */
			*location += sym->st_value - (uint32_t)location;
			break;
		default:
			pr_err("%s: Unknown relocation: %u\n",
			       me->name, ELF32_R_TYPE(rel[i].r_info));
			return -ENOEXEC;
		}
	}
	return 0;
}
#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:
			pr_err("%s: Unknown rela relocation: %llu\n",
			       me->name, ELF64_R_TYPE(rel[i].r_info));
			return -ENOEXEC;
		}
	}
	return 0;

overflow:
	pr_err("overflow in relocation type %d val %Lx\n",
	       (int)ELF64_R_TYPE(rel[i].r_info), val);
	pr_err("`%s' likely not compiled with -mcmodel=kernel\n",
	       me->name);
	return -ENOEXEC;
}
#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	*/
c767a54b JP	18
	19	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	20
2d5bf28f AW	21	#include <linux/moduleloader.h>
	22	#include <linux/elf.h>
	23	#include <linux/vmalloc.h>
	24	#include <linux/fs.h>
	25	#include <linux/string.h>
	26	#include <linux/kernel.h>
	27	#include <linux/bug.h>
	28	#include <linux/mm.h>
5a0e3ad6	29	#include <linux/gfp.h>
d430d3d7	30	#include <linux/jump_label.h>
2d5bf28f	31
2d5bf28f AW	32	#include <asm/page.h>
	33	#include <asm/pgtable.h>
	34
	35	#if 0
c767a54b JP	36	#define DEBUGP(fmt, ...) \
c767a54b JP	37	printk(KERN_DEBUG fmt, ##__VA_ARGS__)
2d5bf28f	38	#else
c767a54b JP	39	#define DEBUGP(fmt, ...) \
	40	do { \
	41	if (0) \
	42	printk(KERN_DEBUG fmt, ##__VA_ARGS__); \
	43	} while (0)
2d5bf28f AW	44	#endif
2d5bf28f AW	45
0fdc83b9 AW	46	void *module_alloc(unsigned long size)
0fdc83b9 AW	47	{
d0a21265	48	if (PAGE_ALIGN(size) > MODULES_LEN)
0fdc83b9	49	return NULL;
d0a21265 DR	50	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
	51	GFP_KERNEL \| __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
	52	-1, __builtin_return_address(0));
0fdc83b9	53	}
0fdc83b9	54
0fdc83b9 AW	55	#ifdef CONFIG_X86_32
	56	int apply_relocate(Elf32_Shdr *sechdrs,
	57	const char *strtab,
	58	unsigned int symindex,
	59	unsigned int relsec,
	60	struct module *me)
	61	{
	62	unsigned int i;
	63	Elf32_Rel rel = (void )sechdrs[relsec].sh_addr;
	64	Elf32_Sym *sym;
	65	uint32_t *location;
	66
c767a54b JP	67	DEBUGP("Applying relocate section %u to %u\n",
c767a54b JP	68	relsec, sechdrs[relsec].sh_info);
0fdc83b9 AW	69	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
	70	/* This is where to make the change */
	71	location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
	72	+ rel[i].r_offset;
	73	/* This is the symbol it is referring to. Note that all
	74	undefined symbols have been resolved. */
	75	sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
	76	+ ELF32_R_SYM(rel[i].r_info);
	77
	78	switch (ELF32_R_TYPE(rel[i].r_info)) {
	79	case R_386_32:
	80	/* We add the value into the location given */
	81	*location += sym->st_value;
	82	break;
	83	case R_386_PC32:
2e76c283	84	/* Add the value, subtract its position */
0fdc83b9 AW	85	*location += sym->st_value - (uint32_t)location;
	86	break;
	87	default:
c767a54b	88	pr_err("%s: Unknown relocation: %u\n",
0fdc83b9 AW	89	me->name, ELF32_R_TYPE(rel[i].r_info));
	90	return -ENOEXEC;
	91	}
	92	}
	93	return 0;
	94	}
0fdc83b9 AW	95	#else /X86_64/
	96	int apply_relocate_add(Elf64_Shdr *sechdrs,
	97	const char *strtab,
	98	unsigned int symindex,
	99	unsigned int relsec,
	100	struct module *me)
	101	{
	102	unsigned int i;
	103	Elf64_Rela rel = (void )sechdrs[relsec].sh_addr;
	104	Elf64_Sym *sym;
	105	void *loc;
	106	u64 val;
	107
c767a54b JP	108	DEBUGP("Applying relocate section %u to %u\n",
c767a54b JP	109	relsec, sechdrs[relsec].sh_info);
0fdc83b9 AW	110	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
	111	/* This is where to make the change */
	112	loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
	113	+ rel[i].r_offset;
	114
	115	/* This is the symbol it is referring to. Note that all
	116	undefined symbols have been resolved. */
	117	sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
	118	+ ELF64_R_SYM(rel[i].r_info);
	119
	120	DEBUGP("type %d st_value %Lx r_addend %Lx loc %Lx\n",
c767a54b JP	121	(int)ELF64_R_TYPE(rel[i].r_info),
c767a54b JP	122	sym->st_value, rel[i].r_addend, (u64)loc);
0fdc83b9 AW	123
	124	val = sym->st_value + rel[i].r_addend;
	125
	126	switch (ELF64_R_TYPE(rel[i].r_info)) {
	127	case R_X86_64_NONE:
	128	break;
	129	case R_X86_64_64:
	130	(u64 )loc = val;
	131	break;
	132	case R_X86_64_32:
	133	(u32 )loc = val;
	134	if (val != (u32 )loc)
	135	goto overflow;
	136	break;
	137	case R_X86_64_32S:
	138	(s32 )loc = val;
	139	if ((s64)val != (s32 )loc)
	140	goto overflow;
	141	break;
	142	case R_X86_64_PC32:
	143	val -= (u64)loc;
	144	(u32 )loc = val;
	145	#if 0
	146	if ((s64)val != (s32 )loc)
	147	goto overflow;
	148	#endif
	149	break;
	150	default:
c767a54b	151	pr_err("%s: Unknown rela relocation: %llu\n",
0fdc83b9 AW	152	me->name, ELF64_R_TYPE(rel[i].r_info));
	153	return -ENOEXEC;
	154	}
	155	}
	156	return 0;
	157
	158	overflow:
c767a54b	159	pr_err("overflow in relocation type %d val %Lx\n",
0fdc83b9	160	(int)ELF64_R_TYPE(rel[i].r_info), val);
c767a54b	161	pr_err("`%s' likely not compiled with -mcmodel=kernel\n",
0fdc83b9 AW	162	me->name);
	163	return -ENOEXEC;
	164	}
0fdc83b9 AW	165	#endif
0fdc83b9 AW	166
2d5bf28f AW	167	int module_finalize(const Elf_Ehdr *hdr,
	168	const Elf_Shdr *sechdrs,
	169	struct module *me)
	170	{
	171	const Elf_Shdr s, text = NULL, alt = NULL, locks = NULL,
	172	*para = NULL;
	173	char secstrings = (void )hdr + sechdrs[hdr->e_shstrndx].sh_offset;
	174
	175	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
	176	if (!strcmp(".text", secstrings + s->sh_name))
	177	text = s;
	178	if (!strcmp(".altinstructions", secstrings + s->sh_name))
	179	alt = s;
	180	if (!strcmp(".smp_locks", secstrings + s->sh_name))
	181	locks = s;
	182	if (!strcmp(".parainstructions", secstrings + s->sh_name))
	183	para = s;
	184	}
	185
	186	if (alt) {
	187	/* patch .altinstructions */
	188	void aseg = (void )alt->sh_addr;
	189	apply_alternatives(aseg, aseg + alt->sh_size);
	190	}
	191	if (locks && text) {
	192	void lseg = (void )locks->sh_addr;
	193	void tseg = (void )text->sh_addr;
	194	alternatives_smp_module_add(me, me->name,
	195	lseg, lseg + locks->sh_size,
	196	tseg, tseg + text->sh_size);
	197	}
	198
	199	if (para) {
	200	void pseg = (void )para->sh_addr;
	201	apply_paravirt(pseg, pseg + para->sh_size);
	202	}
	203
d9f5ab7b JB	204	/* make jump label nops */
	205	jump_label_apply_nops(me);
	206
5336377d	207	return 0;
2d5bf28f AW	208	}
	209
	210	void module_arch_cleanup(struct module *mod)
	211	{
	212	alternatives_smp_module_del(mod);
2d5bf28f	213	}