arch/arm/kernel/module.c - kernel/prism - Git at Google

 /*
  *  linux/arch/arm/kernel/module.c
  *
  *  Copyright (C) 2002 Russell King.
  *  Modified for nommu by Hyok S. Choi
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * Module allocation method suggested by Andi Kleen.
  */
 #include <linux/module.h>
 #include <linux/moduleloader.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/elf.h>
 #include <linux/vmalloc.h>
 #include <linux/slab.h>
 #include <linux/fs.h>
 #include <linux/string.h>

 #include <asm/pgtable.h>
 #include <asm/sections.h>
 #include <asm/unwind.h>

 #ifdef CONFIG_XIP_KERNEL
 /*
  * The XIP kernel text is mapped in the module area for modules and
  * some other stuff to work without any indirect relocations.
  * MODULES_VADDR is redefined here and not in asm/memory.h to avoid
  * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off.
  */
 #undef MODULES_VADDR
 #define MODULES_VADDR	(((unsigned long)_etext + ~PGDIR_MASK) & PGDIR_MASK)
 #endif

 #ifdef CONFIG_MMU
 void *module_alloc(unsigned long size)
 {
 	struct vm_struct *area;

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

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

 	return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL_EXEC);
 }
 #else /* CONFIG_MMU */
 void *module_alloc(unsigned long size)
 {
 	return size == 0 ? NULL : vmalloc(size);
 }
 #endif /* !CONFIG_MMU */

 void module_free(struct module *module, void *region)
 {
 	vfree(region);
 }

 int module_frob_arch_sections(Elf_Ehdr *hdr,
 			      Elf_Shdr *sechdrs,
 			      char *secstrings,
 			      struct module *mod)
 {
 #ifdef CONFIG_ARM_UNWIND
 	Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum;

 	for (s = sechdrs; s < sechdrs_end; s++) {
 		if (strcmp(".ARM.exidx.init.text", secstrings + s->sh_name) == 0)
 			mod->arch.unw_sec_init = s;
 		else if (strcmp(".ARM.exidx.devinit.text", secstrings + s->sh_name) == 0)
 			mod->arch.unw_sec_devinit = s;
 		else if (strcmp(".ARM.exidx", secstrings + s->sh_name) == 0)
 			mod->arch.unw_sec_core = s;
 		else if (strcmp(".init.text", secstrings + s->sh_name) == 0)
 			mod->arch.sec_init_text = s;
 		else if (strcmp(".devinit.text", secstrings + s->sh_name) == 0)
 			mod->arch.sec_devinit_text = s;
 		else if (strcmp(".text", secstrings + s->sh_name) == 0)
 			mod->arch.sec_core_text = s;
 	}
 #endif
 	return 0;
 }

 int
 apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
 	       unsigned int relindex, struct module *module)
 {
 	Elf32_Shdr *symsec = sechdrs + symindex;
 	Elf32_Shdr *relsec = sechdrs + relindex;
 	Elf32_Shdr *dstsec = sechdrs + relsec->sh_info;
 	Elf32_Rel *rel = (void *)relsec->sh_addr;
 	unsigned int i;

 	for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) {
 		unsigned long loc;
 		Elf32_Sym *sym;
 		s32 offset;
 		u32 upper, lower, sign, j1, j2;

 		offset = ELF32_R_SYM(rel->r_info);
 		if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) {
 			printk(KERN_ERR "%s: bad relocation, section %d reloc %d\n",
 				module->name, relindex, i);
 			return -ENOEXEC;
 		}

 		sym = ((Elf32_Sym *)symsec->sh_addr) + offset;

 		if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) {
 			printk(KERN_ERR "%s: out of bounds relocation, "
 				"section %d reloc %d offset %d size %d\n",
 				module->name, relindex, i, rel->r_offset,
 				dstsec->sh_size);
 			return -ENOEXEC;
 		}

 		loc = dstsec->sh_addr + rel->r_offset;

 		switch (ELF32_R_TYPE(rel->r_info)) {
 		case R_ARM_NONE:
 			/* ignore */
 			break;

 		case R_ARM_ABS32:
 			*(u32 *)loc += sym->st_value;
 			break;

 		case R_ARM_PC24:
 		case R_ARM_CALL:
 		case R_ARM_JUMP24:
 			offset = (*(u32 *)loc & 0x00ffffff) << 2;
 			if (offset & 0x02000000)
 				offset -= 0x04000000;

 			offset += sym->st_value - loc;
 			if (offset & 3 ||
 			    offset <= (s32)0xfe000000 ||
 			    offset >= (s32)0x02000000) {
 				printk(KERN_ERR
 				       "%s: relocation out of range, section "
 				       "%d reloc %d sym '%s'\n", module->name,
 				       relindex, i, strtab + sym->st_name);
 				return -ENOEXEC;
 			}

 			offset >>= 2;

 			*(u32 *)loc &= 0xff000000;
 			*(u32 *)loc |= offset & 0x00ffffff;
 			break;

 	       case R_ARM_V4BX:
 		       /* Preserve Rm and the condition code. Alter
 			* other bits to re-code instruction as
 			* MOV PC,Rm.
 			*/
 		       *(u32 *)loc &= 0xf000000f;
 		       *(u32 *)loc |= 0x01a0f000;
 		       break;

 		case R_ARM_PREL31:
 			offset = *(u32 *)loc + sym->st_value - loc;
 			*(u32 *)loc = offset & 0x7fffffff;
 			break;

 		case R_ARM_MOVW_ABS_NC:
 		case R_ARM_MOVT_ABS:
 			offset = *(u32 *)loc;
 			offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff);
 			offset = (offset ^ 0x8000) - 0x8000;

 			offset += sym->st_value;
 			if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS)
 				offset >>= 16;

 			*(u32 *)loc &= 0xfff0f000;
 			*(u32 *)loc |= ((offset & 0xf000) << 4) |
 					(offset & 0x0fff);
 			break;

 		case R_ARM_THM_CALL:
 		case R_ARM_THM_JUMP24:
 			upper = *(u16 *)loc;
 			lower = *(u16 *)(loc + 2);

 			/*
 			 * 25 bit signed address range (Thumb-2 BL and B.W
 			 * instructions):
 			 *   S:I1:I2:imm10:imm11:0
 			 * where:
 			 *   S     = upper[10]   = offset[24]
 			 *   I1    = ~(J1 ^ S)   = offset[23]
 			 *   I2    = ~(J2 ^ S)   = offset[22]
 			 *   imm10 = upper[9:0]  = offset[21:12]
 			 *   imm11 = lower[10:0] = offset[11:1]
 			 *   J1    = lower[13]
 			 *   J2    = lower[11]
 			 */
 			sign = (upper >> 10) & 1;
 			j1 = (lower >> 13) & 1;
 			j2 = (lower >> 11) & 1;
 			offset = (sign << 24) | ((~(j1 ^ sign) & 1) << 23) |
 				((~(j2 ^ sign) & 1) << 22) |
 				((upper & 0x03ff) << 12) |
 				((lower & 0x07ff) << 1);
 			if (offset & 0x01000000)
 				offset -= 0x02000000;
 			offset += sym->st_value - loc;

 			/* only Thumb addresses allowed (no interworking) */
 			if (!(offset & 1) ||
 			    offset <= (s32)0xff000000 ||
 			    offset >= (s32)0x01000000) {
 				printk(KERN_ERR
 				       "%s: relocation out of range, section "
 				       "%d reloc %d sym '%s'\n", module->name,
 				       relindex, i, strtab + sym->st_name);
 				return -ENOEXEC;
 			}

 			sign = (offset >> 24) & 1;
 			j1 = sign ^ (~(offset >> 23) & 1);
 			j2 = sign ^ (~(offset >> 22) & 1);
 			*(u16 *)loc = (u16)((upper & 0xf800) | (sign << 10) |
 					    ((offset >> 12) & 0x03ff));
 			*(u16 *)(loc + 2) = (u16)((lower & 0xd000) |
 						  (j1 << 13) | (j2 << 11) |
 						  ((offset >> 1) & 0x07ff));
 			upper = *(u16 *)loc;
 			lower = *(u16 *)(loc + 2);
 			break;

 		default:
 			printk(KERN_ERR "%s: unknown relocation: %u\n",
 			       module->name, ELF32_R_TYPE(rel->r_info));
 			return -ENOEXEC;
 		}
 	}
 	return 0;
 }

 int
 apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
 		   unsigned int symindex, unsigned int relsec, struct module *module)
 {
 	printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
 	       module->name);
 	return -ENOEXEC;
 }

 #ifdef CONFIG_ARM_UNWIND
 static void register_unwind_tables(struct module *mod)
 {
 	if (mod->arch.unw_sec_init && mod->arch.sec_init_text)
 		mod->arch.unwind_init =
 			unwind_table_add(mod->arch.unw_sec_init->sh_addr,
 					 mod->arch.unw_sec_init->sh_size,
 					 mod->arch.sec_init_text->sh_addr,
 					 mod->arch.sec_init_text->sh_size);
 	if (mod->arch.unw_sec_devinit && mod->arch.sec_devinit_text)
 		mod->arch.unwind_devinit =
 			unwind_table_add(mod->arch.unw_sec_devinit->sh_addr,
 					 mod->arch.unw_sec_devinit->sh_size,
 					 mod->arch.sec_devinit_text->sh_addr,
 					 mod->arch.sec_devinit_text->sh_size);
 	if (mod->arch.unw_sec_core && mod->arch.sec_core_text)
 		mod->arch.unwind_core =
 			unwind_table_add(mod->arch.unw_sec_core->sh_addr,
 					 mod->arch.unw_sec_core->sh_size,
 					 mod->arch.sec_core_text->sh_addr,
 					 mod->arch.sec_core_text->sh_size);
 }

 static void unregister_unwind_tables(struct module *mod)
 {
 	unwind_table_del(mod->arch.unwind_init);
 	unwind_table_del(mod->arch.unwind_devinit);
 	unwind_table_del(mod->arch.unwind_core);
 }
 #else
 static inline void register_unwind_tables(struct module *mod) { }
 static inline void unregister_unwind_tables(struct module *mod) { }
 #endif

 int
 module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
 		struct module *module)
 {
 	register_unwind_tables(module);
 	return 0;
 }

 void
 module_arch_cleanup(struct module *mod)
 {
 	unregister_unwind_tables(mod);
 }
	/*
	* linux/arch/arm/kernel/module.c
	*
	* Copyright (C) 2002 Russell King.
	* Modified for nommu by Hyok S. Choi
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* Module allocation method suggested by Andi Kleen.
	*/
	#include <linux/module.h>
	#include <linux/moduleloader.h>
	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/elf.h>
	#include <linux/vmalloc.h>
	#include <linux/slab.h>
	#include <linux/fs.h>
	#include <linux/string.h>

	#include <asm/pgtable.h>
	#include <asm/sections.h>
	#include <asm/unwind.h>

	#ifdef CONFIG_XIP_KERNEL
	/*
	* The XIP kernel text is mapped in the module area for modules and
	* some other stuff to work without any indirect relocations.
	* MODULES_VADDR is redefined here and not in asm/memory.h to avoid
	* recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off.
	*/
	#undef MODULES_VADDR
	#define MODULES_VADDR (((unsigned long)_etext + ~PGDIR_MASK) & PGDIR_MASK)
	#endif

	#ifdef CONFIG_MMU
	void *module_alloc(unsigned long size)
	{
	struct vm_struct *area;

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

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

	return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL_EXEC);
	}
	#else /* CONFIG_MMU */
	void *module_alloc(unsigned long size)
	{
	return size == 0 ? NULL : vmalloc(size);
	}
	#endif /* !CONFIG_MMU */

	void module_free(struct module module, void region)
	{
	vfree(region);
	}

	int module_frob_arch_sections(Elf_Ehdr *hdr,
	Elf_Shdr *sechdrs,
	char *secstrings,
	struct module *mod)
	{
	#ifdef CONFIG_ARM_UNWIND
	Elf_Shdr s, sechdrs_end = sechdrs + hdr->e_shnum;

	for (s = sechdrs; s < sechdrs_end; s++) {
	if (strcmp(".ARM.exidx.init.text", secstrings + s->sh_name) == 0)
	mod->arch.unw_sec_init = s;
	else if (strcmp(".ARM.exidx.devinit.text", secstrings + s->sh_name) == 0)
	mod->arch.unw_sec_devinit = s;
	else if (strcmp(".ARM.exidx", secstrings + s->sh_name) == 0)
	mod->arch.unw_sec_core = s;
	else if (strcmp(".init.text", secstrings + s->sh_name) == 0)
	mod->arch.sec_init_text = s;
	else if (strcmp(".devinit.text", secstrings + s->sh_name) == 0)
	mod->arch.sec_devinit_text = s;
	else if (strcmp(".text", secstrings + s->sh_name) == 0)
	mod->arch.sec_core_text = s;
	}
	#endif
	return 0;
	}

	int
	apply_relocate(Elf32_Shdr sechdrs, const char strtab, unsigned int symindex,
	unsigned int relindex, struct module *module)
	{
	Elf32_Shdr *symsec = sechdrs + symindex;
	Elf32_Shdr *relsec = sechdrs + relindex;
	Elf32_Shdr *dstsec = sechdrs + relsec->sh_info;
	Elf32_Rel rel = (void )relsec->sh_addr;
	unsigned int i;

	for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) {
	unsigned long loc;
	Elf32_Sym *sym;
	s32 offset;
	u32 upper, lower, sign, j1, j2;

	offset = ELF32_R_SYM(rel->r_info);
	if (offset < 0 \|\| offset > (symsec->sh_size / sizeof(Elf32_Sym))) {
	printk(KERN_ERR "%s: bad relocation, section %d reloc %d\n",
	module->name, relindex, i);
	return -ENOEXEC;
	}

	sym = ((Elf32_Sym *)symsec->sh_addr) + offset;

	if (rel->r_offset < 0 \|\| rel->r_offset > dstsec->sh_size - sizeof(u32)) {
	printk(KERN_ERR "%s: out of bounds relocation, "
	"section %d reloc %d offset %d size %d\n",
	module->name, relindex, i, rel->r_offset,
	dstsec->sh_size);
	return -ENOEXEC;
	}

	loc = dstsec->sh_addr + rel->r_offset;

	switch (ELF32_R_TYPE(rel->r_info)) {
	case R_ARM_NONE:
	/* ignore */
	break;

	case R_ARM_ABS32:
	(u32 )loc += sym->st_value;
	break;

	case R_ARM_PC24:
	case R_ARM_CALL:
	case R_ARM_JUMP24:
	offset = ((u32 )loc & 0x00ffffff) << 2;
	if (offset & 0x02000000)
	offset -= 0x04000000;

	offset += sym->st_value - loc;
	if (offset & 3 \|\|
	offset <= (s32)0xfe000000 \|\|
	offset >= (s32)0x02000000) {
	printk(KERN_ERR
	"%s: relocation out of range, section "
	"%d reloc %d sym '%s'\n", module->name,
	relindex, i, strtab + sym->st_name);
	return -ENOEXEC;
	}

	offset >>= 2;

	(u32 )loc &= 0xff000000;
	(u32 )loc \|= offset & 0x00ffffff;
	break;

	case R_ARM_V4BX:
	/* Preserve Rm and the condition code. Alter
	* other bits to re-code instruction as
	* MOV PC,Rm.
	*/
	(u32 )loc &= 0xf000000f;
	(u32 )loc \|= 0x01a0f000;
	break;

	case R_ARM_PREL31:
	offset = (u32 )loc + sym->st_value - loc;
	(u32 )loc = offset & 0x7fffffff;
	break;

	case R_ARM_MOVW_ABS_NC:
	case R_ARM_MOVT_ABS:
	offset = (u32 )loc;
	offset = ((offset & 0xf0000) >> 4) \| (offset & 0xfff);
	offset = (offset ^ 0x8000) - 0x8000;

	offset += sym->st_value;
	if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS)
	offset >>= 16;

	(u32 )loc &= 0xfff0f000;
	(u32 )loc \|= ((offset & 0xf000) << 4) \|
	(offset & 0x0fff);
	break;

	case R_ARM_THM_CALL:
	case R_ARM_THM_JUMP24:
	upper = (u16 )loc;
	lower = (u16 )(loc + 2);

	/*
	* 25 bit signed address range (Thumb-2 BL and B.W
	* instructions):
	* S:I1:I2:imm10:imm11:0
	* where:
	* S = upper[10] = offset[24]
	* I1 = ~(J1 ^ S) = offset[23]
	* I2 = ~(J2 ^ S) = offset[22]
	* imm10 = upper[9:0] = offset[21:12]
	* imm11 = lower[10:0] = offset[11:1]
	* J1 = lower[13]
	* J2 = lower[11]
	*/
	sign = (upper >> 10) & 1;
	j1 = (lower >> 13) & 1;
	j2 = (lower >> 11) & 1;
	offset = (sign << 24) \| ((~(j1 ^ sign) & 1) << 23) \|
	((~(j2 ^ sign) & 1) << 22) \|
	((upper & 0x03ff) << 12) \|
	((lower & 0x07ff) << 1);
	if (offset & 0x01000000)
	offset -= 0x02000000;
	offset += sym->st_value - loc;

	/* only Thumb addresses allowed (no interworking) */
	if (!(offset & 1) \|\|
	offset <= (s32)0xff000000 \|\|
	offset >= (s32)0x01000000) {
	printk(KERN_ERR
	"%s: relocation out of range, section "
	"%d reloc %d sym '%s'\n", module->name,
	relindex, i, strtab + sym->st_name);
	return -ENOEXEC;
	}

	sign = (offset >> 24) & 1;
	j1 = sign ^ (~(offset >> 23) & 1);
	j2 = sign ^ (~(offset >> 22) & 1);
	(u16 )loc = (u16)((upper & 0xf800) \| (sign << 10) \|
	((offset >> 12) & 0x03ff));
	(u16 )(loc + 2) = (u16)((lower & 0xd000) \|
	(j1 << 13) \| (j2 << 11) \|
	((offset >> 1) & 0x07ff));
	upper = (u16 )loc;
	lower = (u16 )(loc + 2);
	break;

	default:
	printk(KERN_ERR "%s: unknown relocation: %u\n",
	module->name, ELF32_R_TYPE(rel->r_info));
	return -ENOEXEC;
	}
	}
	return 0;
	}

	int
	apply_relocate_add(Elf32_Shdr sechdrs, const char strtab,
	unsigned int symindex, unsigned int relsec, struct module *module)
	{
	printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
	module->name);
	return -ENOEXEC;
	}

	#ifdef CONFIG_ARM_UNWIND
	static void register_unwind_tables(struct module *mod)
	{
	if (mod->arch.unw_sec_init && mod->arch.sec_init_text)
	mod->arch.unwind_init =
	unwind_table_add(mod->arch.unw_sec_init->sh_addr,
	mod->arch.unw_sec_init->sh_size,
	mod->arch.sec_init_text->sh_addr,
	mod->arch.sec_init_text->sh_size);
	if (mod->arch.unw_sec_devinit && mod->arch.sec_devinit_text)
	mod->arch.unwind_devinit =
	unwind_table_add(mod->arch.unw_sec_devinit->sh_addr,
	mod->arch.unw_sec_devinit->sh_size,
	mod->arch.sec_devinit_text->sh_addr,
	mod->arch.sec_devinit_text->sh_size);
	if (mod->arch.unw_sec_core && mod->arch.sec_core_text)
	mod->arch.unwind_core =
	unwind_table_add(mod->arch.unw_sec_core->sh_addr,
	mod->arch.unw_sec_core->sh_size,
	mod->arch.sec_core_text->sh_addr,
	mod->arch.sec_core_text->sh_size);
	}

	static void unregister_unwind_tables(struct module *mod)
	{
	unwind_table_del(mod->arch.unwind_init);
	unwind_table_del(mod->arch.unwind_devinit);
	unwind_table_del(mod->arch.unwind_core);
	}
	#else
	static inline void register_unwind_tables(struct module *mod) { }
	static inline void unregister_unwind_tables(struct module *mod) { }
	#endif

	int
	module_finalize(const Elf32_Ehdr hdr, const Elf_Shdr sechdrs,
	struct module *module)
	{
	register_unwind_tables(module);
	return 0;
	}

	void
	module_arch_cleanup(struct module *mod)
	{
	unregister_unwind_tables(mod);
	}