arch/riscv/kernel/module.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *
  *  Copyright (C) 2017 Zihao Yu
  */

 #include <linux/elf.h>
 #include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/moduleloader.h>
 #include <linux/vmalloc.h>
 #include <linux/sizes.h>
 #include <linux/pgtable.h>
 #include <asm/alternative.h>
 #include <asm/sections.h>

 /*
  * The auipc+jalr instruction pair can reach any PC-relative offset
  * in the range [-2^31 - 2^11, 2^31 - 2^11)
  */
 static bool riscv_insn_valid_32bit_offset(ptrdiff_t val)
 {
 #ifdef CONFIG_32BIT
 	return true;
 #else
 	return (-(1L << 31) - (1L << 11)) <= val && val < ((1L << 31) - (1L << 11));
 #endif
 }

 static int apply_r_riscv_32_rela(struct module *me, u32 *location, Elf_Addr v)
 {
 	if (v != (u32)v) {
 		pr_err("%s: value %016llx out of range for 32-bit field\n",
 		       me->name, (long long)v);
 		return -EINVAL;
 	}
 	*location = v;
 	return 0;
 }

 static int apply_r_riscv_64_rela(struct module *me, u32 *location, Elf_Addr v)
 {
 	*(u64 *)location = v;
 	return 0;
 }

 static int apply_r_riscv_branch_rela(struct module *me, u32 *location,
 				     Elf_Addr v)
 {
 	ptrdiff_t offset = (void *)v - (void *)location;
 	u32 imm12 = (offset & 0x1000) << (31 - 12);
 	u32 imm11 = (offset & 0x800) >> (11 - 7);
 	u32 imm10_5 = (offset & 0x7e0) << (30 - 10);
 	u32 imm4_1 = (offset & 0x1e) << (11 - 4);

 	*location = (*location & 0x1fff07f) | imm12 | imm11 | imm10_5 | imm4_1;
 	return 0;
 }

 static int apply_r_riscv_jal_rela(struct module *me, u32 *location,
 				  Elf_Addr v)
 {
 	ptrdiff_t offset = (void *)v - (void *)location;
 	u32 imm20 = (offset & 0x100000) << (31 - 20);
 	u32 imm19_12 = (offset & 0xff000);
 	u32 imm11 = (offset & 0x800) << (20 - 11);
 	u32 imm10_1 = (offset & 0x7fe) << (30 - 10);

 	*location = (*location & 0xfff) | imm20 | imm19_12 | imm11 | imm10_1;
 	return 0;
 }

 static int apply_r_riscv_rvc_branch_rela(struct module *me, u32 *location,
 					 Elf_Addr v)
 {
 	ptrdiff_t offset = (void *)v - (void *)location;
 	u16 imm8 = (offset & 0x100) << (12 - 8);
 	u16 imm7_6 = (offset & 0xc0) >> (6 - 5);
 	u16 imm5 = (offset & 0x20) >> (5 - 2);
 	u16 imm4_3 = (offset & 0x18) << (12 - 5);
 	u16 imm2_1 = (offset & 0x6) << (12 - 10);

 	*(u16 *)location = (*(u16 *)location & 0xe383) |
 		    imm8 | imm7_6 | imm5 | imm4_3 | imm2_1;
 	return 0;
 }

 static int apply_r_riscv_rvc_jump_rela(struct module *me, u32 *location,
 				       Elf_Addr v)
 {
 	ptrdiff_t offset = (void *)v - (void *)location;
 	u16 imm11 = (offset & 0x800) << (12 - 11);
 	u16 imm10 = (offset & 0x400) >> (10 - 8);
 	u16 imm9_8 = (offset & 0x300) << (12 - 11);
 	u16 imm7 = (offset & 0x80) >> (7 - 6);
 	u16 imm6 = (offset & 0x40) << (12 - 11);
 	u16 imm5 = (offset & 0x20) >> (5 - 2);
 	u16 imm4 = (offset & 0x10) << (12 - 5);
 	u16 imm3_1 = (offset & 0xe) << (12 - 10);

 	*(u16 *)location = (*(u16 *)location & 0xe003) |
 		    imm11 | imm10 | imm9_8 | imm7 | imm6 | imm5 | imm4 | imm3_1;
 	return 0;
 }

 static int apply_r_riscv_pcrel_hi20_rela(struct module *me, u32 *location,
 					 Elf_Addr v)
 {
 	ptrdiff_t offset = (void *)v - (void *)location;
 	s32 hi20;

 	if (!riscv_insn_valid_32bit_offset(offset)) {
 		pr_err(
 		  "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
 		  me->name, (long long)v, location);
 		return -EINVAL;
 	}

 	hi20 = (offset + 0x800) & 0xfffff000;
 	*location = (*location & 0xfff) | hi20;
 	return 0;
 }

 static int apply_r_riscv_pcrel_lo12_i_rela(struct module *me, u32 *location,
 					   Elf_Addr v)
 {
 	/*
 	 * v is the lo12 value to fill. It is calculated before calling this
 	 * handler.
 	 */
 	*location = (*location & 0xfffff) | ((v & 0xfff) << 20);
 	return 0;
 }

 static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location,
 					   Elf_Addr v)
 {
 	/*
 	 * v is the lo12 value to fill. It is calculated before calling this
 	 * handler.
 	 */
 	u32 imm11_5 = (v & 0xfe0) << (31 - 11);
 	u32 imm4_0 = (v & 0x1f) << (11 - 4);

 	*location = (*location & 0x1fff07f) | imm11_5 | imm4_0;
 	return 0;
 }

 static int apply_r_riscv_hi20_rela(struct module *me, u32 *location,
 				   Elf_Addr v)
 {
 	s32 hi20;

 	if (IS_ENABLED(CONFIG_CMODEL_MEDLOW)) {
 		pr_err(
 		  "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
 		  me->name, (long long)v, location);
 		return -EINVAL;
 	}

 	hi20 = ((s32)v + 0x800) & 0xfffff000;
 	*location = (*location & 0xfff) | hi20;
 	return 0;
 }

 static int apply_r_riscv_lo12_i_rela(struct module *me, u32 *location,
 				     Elf_Addr v)
 {
 	/* Skip medlow checking because of filtering by HI20 already */
 	s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
 	s32 lo12 = ((s32)v - hi20);
 	*location = (*location & 0xfffff) | ((lo12 & 0xfff) << 20);
 	return 0;
 }

 static int apply_r_riscv_lo12_s_rela(struct module *me, u32 *location,
 				     Elf_Addr v)
 {
 	/* Skip medlow checking because of filtering by HI20 already */
 	s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
 	s32 lo12 = ((s32)v - hi20);
 	u32 imm11_5 = (lo12 & 0xfe0) << (31 - 11);
 	u32 imm4_0 = (lo12 & 0x1f) << (11 - 4);
 	*location = (*location & 0x1fff07f) | imm11_5 | imm4_0;
 	return 0;
 }

 static int apply_r_riscv_got_hi20_rela(struct module *me, u32 *location,
 				       Elf_Addr v)
 {
 	ptrdiff_t offset = (void *)v - (void *)location;
 	s32 hi20;

 	/* Always emit the got entry */
 	if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) {
 		offset = module_emit_got_entry(me, v);
 		offset = (void *)offset - (void *)location;
 	} else {
 		pr_err(
 		  "%s: can not generate the GOT entry for symbol = %016llx from PC = %p\n",
 		  me->name, (long long)v, location);
 		return -EINVAL;
 	}

 	hi20 = (offset + 0x800) & 0xfffff000;
 	*location = (*location & 0xfff) | hi20;
 	return 0;
 }

 static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location,
 				       Elf_Addr v)
 {
 	ptrdiff_t offset = (void *)v - (void *)location;
 	u32 hi20, lo12;

 	if (!riscv_insn_valid_32bit_offset(offset)) {
 		/* Only emit the plt entry if offset over 32-bit range */
 		if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) {
 			offset = module_emit_plt_entry(me, v);
 			offset = (void *)offset - (void *)location;
 		} else {
 			pr_err(
 			  "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
 			  me->name, (long long)v, location);
 			return -EINVAL;
 		}
 	}

 	hi20 = (offset + 0x800) & 0xfffff000;
 	lo12 = (offset - hi20) & 0xfff;
 	*location = (*location & 0xfff) | hi20;
 	*(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
 	return 0;
 }

 static int apply_r_riscv_call_rela(struct module *me, u32 *location,
 				   Elf_Addr v)
 {
 	ptrdiff_t offset = (void *)v - (void *)location;
 	u32 hi20, lo12;

 	if (!riscv_insn_valid_32bit_offset(offset)) {
 		pr_err(
 		  "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
 		  me->name, (long long)v, location);
 		return -EINVAL;
 	}

 	hi20 = (offset + 0x800) & 0xfffff000;
 	lo12 = (offset - hi20) & 0xfff;
 	*location = (*location & 0xfff) | hi20;
 	*(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
 	return 0;
 }

 static int apply_r_riscv_relax_rela(struct module *me, u32 *location,
 				    Elf_Addr v)
 {
 	return 0;
 }

 static int apply_r_riscv_align_rela(struct module *me, u32 *location,
 				    Elf_Addr v)
 {
 	pr_err(
 	  "%s: The unexpected relocation type 'R_RISCV_ALIGN' from PC = %p\n",
 	  me->name, location);
 	return -EINVAL;
 }

 static int apply_r_riscv_add32_rela(struct module *me, u32 *location,
 				    Elf_Addr v)
 {
 	*(u32 *)location += (u32)v;
 	return 0;
 }

 static int apply_r_riscv_add64_rela(struct module *me, u32 *location,
 				    Elf_Addr v)
 {
 	*(u64 *)location += (u64)v;
 	return 0;
 }

 static int apply_r_riscv_sub32_rela(struct module *me, u32 *location,
 				    Elf_Addr v)
 {
 	*(u32 *)location -= (u32)v;
 	return 0;
 }

 static int apply_r_riscv_sub64_rela(struct module *me, u32 *location,
 				    Elf_Addr v)
 {
 	*(u64 *)location -= (u64)v;
 	return 0;
 }

 static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
 				Elf_Addr v) = {
 	[R_RISCV_32]			= apply_r_riscv_32_rela,
 	[R_RISCV_64]			= apply_r_riscv_64_rela,
 	[R_RISCV_BRANCH]		= apply_r_riscv_branch_rela,
 	[R_RISCV_JAL]			= apply_r_riscv_jal_rela,
 	[R_RISCV_RVC_BRANCH]		= apply_r_riscv_rvc_branch_rela,
 	[R_RISCV_RVC_JUMP]		= apply_r_riscv_rvc_jump_rela,
 	[R_RISCV_PCREL_HI20]		= apply_r_riscv_pcrel_hi20_rela,
 	[R_RISCV_PCREL_LO12_I]		= apply_r_riscv_pcrel_lo12_i_rela,
 	[R_RISCV_PCREL_LO12_S]		= apply_r_riscv_pcrel_lo12_s_rela,
 	[R_RISCV_HI20]			= apply_r_riscv_hi20_rela,
 	[R_RISCV_LO12_I]		= apply_r_riscv_lo12_i_rela,
 	[R_RISCV_LO12_S]		= apply_r_riscv_lo12_s_rela,
 	[R_RISCV_GOT_HI20]		= apply_r_riscv_got_hi20_rela,
 	[R_RISCV_CALL_PLT]		= apply_r_riscv_call_plt_rela,
 	[R_RISCV_CALL]			= apply_r_riscv_call_rela,
 	[R_RISCV_RELAX]			= apply_r_riscv_relax_rela,
 	[R_RISCV_ALIGN]			= apply_r_riscv_align_rela,
 	[R_RISCV_ADD32]			= apply_r_riscv_add32_rela,
 	[R_RISCV_ADD64]			= apply_r_riscv_add64_rela,
 	[R_RISCV_SUB32]			= apply_r_riscv_sub32_rela,
 	[R_RISCV_SUB64]			= apply_r_riscv_sub64_rela,
 };

 int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
 		       unsigned int symindex, unsigned int relsec,
 		       struct module *me)
 {
 	Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr;
 	int (*handler)(struct module *me, u32 *location, Elf_Addr v);
 	Elf_Sym *sym;
 	u32 *location;
 	unsigned int i, type;
 	Elf_Addr v;
 	int res;

 	pr_debug("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 */
 		sym = (Elf_Sym *)sechdrs[symindex].sh_addr
 			+ ELF_RISCV_R_SYM(rel[i].r_info);
 		if (IS_ERR_VALUE(sym->st_value)) {
 			/* Ignore unresolved weak symbol */
 			if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
 				continue;
 			pr_warn("%s: Unknown symbol %s\n",
 				me->name, strtab + sym->st_name);
 			return -ENOENT;
 		}

 		type = ELF_RISCV_R_TYPE(rel[i].r_info);

 		if (type < ARRAY_SIZE(reloc_handlers_rela))
 			handler = reloc_handlers_rela[type];
 		else
 			handler = NULL;

 		if (!handler) {
 			pr_err("%s: Unknown relocation type %u\n",
 			       me->name, type);
 			return -EINVAL;
 		}

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

 		if (type == R_RISCV_PCREL_LO12_I || type == R_RISCV_PCREL_LO12_S) {
 			unsigned int j;

 			for (j = 0; j < sechdrs[relsec].sh_size / sizeof(*rel); j++) {
 				unsigned long hi20_loc =
 					sechdrs[sechdrs[relsec].sh_info].sh_addr
 					+ rel[j].r_offset;
 				u32 hi20_type = ELF_RISCV_R_TYPE(rel[j].r_info);

 				/* Find the corresponding HI20 relocation entry */
 				if (hi20_loc == sym->st_value
 				    && (hi20_type == R_RISCV_PCREL_HI20
 					|| hi20_type == R_RISCV_GOT_HI20)) {
 					s32 hi20, lo12;
 					Elf_Sym *hi20_sym =
 						(Elf_Sym *)sechdrs[symindex].sh_addr
 						+ ELF_RISCV_R_SYM(rel[j].r_info);
 					unsigned long hi20_sym_val =
 						hi20_sym->st_value
 						+ rel[j].r_addend;

 					/* Calculate lo12 */
 					size_t offset = hi20_sym_val - hi20_loc;
 					if (IS_ENABLED(CONFIG_MODULE_SECTIONS)
 					    && hi20_type == R_RISCV_GOT_HI20) {
 						offset = module_emit_got_entry(
 							 me, hi20_sym_val);
 						offset = offset - hi20_loc;
 					}
 					hi20 = (offset + 0x800) & 0xfffff000;
 					lo12 = offset - hi20;
 					v = lo12;

 					break;
 				}
 			}
 			if (j == sechdrs[relsec].sh_size / sizeof(*rel)) {
 				pr_err(
 				  "%s: Can not find HI20 relocation information\n",
 				  me->name);
 				return -EINVAL;
 			}
 		}

 		res = handler(me, location, v);
 		if (res)
 			return res;
 	}

 	return 0;
 }

 #if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
 void *module_alloc(unsigned long size)
 {
 	return __vmalloc_node_range(size, 1, MODULES_VADDR,
 				    MODULES_END, GFP_KERNEL,
 				    PAGE_KERNEL, 0, NUMA_NO_NODE,
 				    __builtin_return_address(0));
 }
 #endif

 static const Elf_Shdr *find_section(const Elf_Ehdr *hdr,
 				    const Elf_Shdr *sechdrs,
 				    const char *name)
 {
 	const Elf_Shdr *s, *se;
 	const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;

 	for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) {
 		if (strcmp(name, secstrs + s->sh_name) == 0)
 			return s;
 	}

 	return NULL;
 }

 int module_finalize(const Elf_Ehdr *hdr,
 		    const Elf_Shdr *sechdrs,
 		    struct module *me)
 {
 	const Elf_Shdr *s;

 	s = find_section(hdr, sechdrs, ".alternative");
 	if (s)
 		apply_module_alternatives((void *)s->sh_addr, s->sh_size);

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	*
	* Copyright (C) 2017 Zihao Yu
	*/

	#include <linux/elf.h>
	#include <linux/err.h>
	#include <linux/errno.h>
	#include <linux/moduleloader.h>
	#include <linux/vmalloc.h>
	#include <linux/sizes.h>
	#include <linux/pgtable.h>
	#include <asm/alternative.h>
	#include <asm/sections.h>

	/*
	* The auipc+jalr instruction pair can reach any PC-relative offset
	* in the range [-2^31 - 2^11, 2^31 - 2^11)
	*/
	static bool riscv_insn_valid_32bit_offset(ptrdiff_t val)
	{
	#ifdef CONFIG_32BIT
	return true;
	#else
	return (-(1L << 31) - (1L << 11)) <= val && val < ((1L << 31) - (1L << 11));
	#endif
	}

	static int apply_r_riscv_32_rela(struct module me, u32 location, Elf_Addr v)
	{
	if (v != (u32)v) {
	pr_err("%s: value %016llx out of range for 32-bit field\n",
	me->name, (long long)v);
	return -EINVAL;
	}
	*location = v;
	return 0;
	}

	static int apply_r_riscv_64_rela(struct module me, u32 location, Elf_Addr v)
	{
	(u64 )location = v;
	return 0;
	}

	static int apply_r_riscv_branch_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	ptrdiff_t offset = (void )v - (void )location;
	u32 imm12 = (offset & 0x1000) << (31 - 12);
	u32 imm11 = (offset & 0x800) >> (11 - 7);
	u32 imm10_5 = (offset & 0x7e0) << (30 - 10);
	u32 imm4_1 = (offset & 0x1e) << (11 - 4);

	location = (location & 0x1fff07f) \| imm12 \| imm11 \| imm10_5 \| imm4_1;
	return 0;
	}

	static int apply_r_riscv_jal_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	ptrdiff_t offset = (void )v - (void )location;
	u32 imm20 = (offset & 0x100000) << (31 - 20);
	u32 imm19_12 = (offset & 0xff000);
	u32 imm11 = (offset & 0x800) << (20 - 11);
	u32 imm10_1 = (offset & 0x7fe) << (30 - 10);

	location = (location & 0xfff) \| imm20 \| imm19_12 \| imm11 \| imm10_1;
	return 0;
	}

	static int apply_r_riscv_rvc_branch_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	ptrdiff_t offset = (void )v - (void )location;
	u16 imm8 = (offset & 0x100) << (12 - 8);
	u16 imm7_6 = (offset & 0xc0) >> (6 - 5);
	u16 imm5 = (offset & 0x20) >> (5 - 2);
	u16 imm4_3 = (offset & 0x18) << (12 - 5);
	u16 imm2_1 = (offset & 0x6) << (12 - 10);

	(u16 )location = ((u16 )location & 0xe383) \|
	imm8 \| imm7_6 \| imm5 \| imm4_3 \| imm2_1;
	return 0;
	}

	static int apply_r_riscv_rvc_jump_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	ptrdiff_t offset = (void )v - (void )location;
	u16 imm11 = (offset & 0x800) << (12 - 11);
	u16 imm10 = (offset & 0x400) >> (10 - 8);
	u16 imm9_8 = (offset & 0x300) << (12 - 11);
	u16 imm7 = (offset & 0x80) >> (7 - 6);
	u16 imm6 = (offset & 0x40) << (12 - 11);
	u16 imm5 = (offset & 0x20) >> (5 - 2);
	u16 imm4 = (offset & 0x10) << (12 - 5);
	u16 imm3_1 = (offset & 0xe) << (12 - 10);

	(u16 )location = ((u16 )location & 0xe003) \|
	imm11 \| imm10 \| imm9_8 \| imm7 \| imm6 \| imm5 \| imm4 \| imm3_1;
	return 0;
	}

	static int apply_r_riscv_pcrel_hi20_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	ptrdiff_t offset = (void )v - (void )location;
	s32 hi20;

	if (!riscv_insn_valid_32bit_offset(offset)) {
	pr_err(
	"%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
	me->name, (long long)v, location);
	return -EINVAL;
	}

	hi20 = (offset + 0x800) & 0xfffff000;
	location = (location & 0xfff) \| hi20;
	return 0;
	}

	static int apply_r_riscv_pcrel_lo12_i_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	/*
	* v is the lo12 value to fill. It is calculated before calling this
	* handler.
	*/
	location = (location & 0xfffff) \| ((v & 0xfff) << 20);
	return 0;
	}

	static int apply_r_riscv_pcrel_lo12_s_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	/*
	* v is the lo12 value to fill. It is calculated before calling this
	* handler.
	*/
	u32 imm11_5 = (v & 0xfe0) << (31 - 11);
	u32 imm4_0 = (v & 0x1f) << (11 - 4);

	location = (location & 0x1fff07f) \| imm11_5 \| imm4_0;
	return 0;
	}

	static int apply_r_riscv_hi20_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	s32 hi20;

	if (IS_ENABLED(CONFIG_CMODEL_MEDLOW)) {
	pr_err(
	"%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
	me->name, (long long)v, location);
	return -EINVAL;
	}

	hi20 = ((s32)v + 0x800) & 0xfffff000;
	location = (location & 0xfff) \| hi20;
	return 0;
	}

	static int apply_r_riscv_lo12_i_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	/* Skip medlow checking because of filtering by HI20 already */
	s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
	s32 lo12 = ((s32)v - hi20);
	location = (location & 0xfffff) \| ((lo12 & 0xfff) << 20);
	return 0;
	}

	static int apply_r_riscv_lo12_s_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	/* Skip medlow checking because of filtering by HI20 already */
	s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
	s32 lo12 = ((s32)v - hi20);
	u32 imm11_5 = (lo12 & 0xfe0) << (31 - 11);
	u32 imm4_0 = (lo12 & 0x1f) << (11 - 4);
	location = (location & 0x1fff07f) \| imm11_5 \| imm4_0;
	return 0;
	}

	static int apply_r_riscv_got_hi20_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	ptrdiff_t offset = (void )v - (void )location;
	s32 hi20;

	/* Always emit the got entry */
	if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) {
	offset = module_emit_got_entry(me, v);
	offset = (void )offset - (void )location;
	} else {
	pr_err(
	"%s: can not generate the GOT entry for symbol = %016llx from PC = %p\n",
	me->name, (long long)v, location);
	return -EINVAL;
	}

	hi20 = (offset + 0x800) & 0xfffff000;
	location = (location & 0xfff) \| hi20;
	return 0;
	}

	static int apply_r_riscv_call_plt_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	ptrdiff_t offset = (void )v - (void )location;
	u32 hi20, lo12;

	if (!riscv_insn_valid_32bit_offset(offset)) {
	/* Only emit the plt entry if offset over 32-bit range */
	if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) {
	offset = module_emit_plt_entry(me, v);
	offset = (void )offset - (void )location;
	} else {
	pr_err(
	"%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
	me->name, (long long)v, location);
	return -EINVAL;
	}
	}

	hi20 = (offset + 0x800) & 0xfffff000;
	lo12 = (offset - hi20) & 0xfff;
	location = (location & 0xfff) \| hi20;
	(location + 1) = ((location + 1) & 0xfffff) \| (lo12 << 20);
	return 0;
	}

	static int apply_r_riscv_call_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	ptrdiff_t offset = (void )v - (void )location;
	u32 hi20, lo12;

	if (!riscv_insn_valid_32bit_offset(offset)) {
	pr_err(
	"%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
	me->name, (long long)v, location);
	return -EINVAL;
	}

	hi20 = (offset + 0x800) & 0xfffff000;
	lo12 = (offset - hi20) & 0xfff;
	location = (location & 0xfff) \| hi20;
	(location + 1) = ((location + 1) & 0xfffff) \| (lo12 << 20);
	return 0;
	}

	static int apply_r_riscv_relax_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	return 0;
	}

	static int apply_r_riscv_align_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	pr_err(
	"%s: The unexpected relocation type 'R_RISCV_ALIGN' from PC = %p\n",
	me->name, location);
	return -EINVAL;
	}

	static int apply_r_riscv_add32_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	(u32 )location += (u32)v;
	return 0;
	}

	static int apply_r_riscv_add64_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	(u64 )location += (u64)v;
	return 0;
	}

	static int apply_r_riscv_sub32_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	(u32 )location -= (u32)v;
	return 0;
	}

	static int apply_r_riscv_sub64_rela(struct module me, u32 location,
	Elf_Addr v)
	{
	(u64 )location -= (u64)v;
	return 0;
	}

	static int (reloc_handlers_rela[]) (struct module me, u32 *location,
	Elf_Addr v) = {
	[R_RISCV_32] = apply_r_riscv_32_rela,
	[R_RISCV_64] = apply_r_riscv_64_rela,
	[R_RISCV_BRANCH] = apply_r_riscv_branch_rela,
	[R_RISCV_JAL] = apply_r_riscv_jal_rela,
	[R_RISCV_RVC_BRANCH] = apply_r_riscv_rvc_branch_rela,
	[R_RISCV_RVC_JUMP] = apply_r_riscv_rvc_jump_rela,
	[R_RISCV_PCREL_HI20] = apply_r_riscv_pcrel_hi20_rela,
	[R_RISCV_PCREL_LO12_I] = apply_r_riscv_pcrel_lo12_i_rela,
	[R_RISCV_PCREL_LO12_S] = apply_r_riscv_pcrel_lo12_s_rela,
	[R_RISCV_HI20] = apply_r_riscv_hi20_rela,
	[R_RISCV_LO12_I] = apply_r_riscv_lo12_i_rela,
	[R_RISCV_LO12_S] = apply_r_riscv_lo12_s_rela,
	[R_RISCV_GOT_HI20] = apply_r_riscv_got_hi20_rela,
	[R_RISCV_CALL_PLT] = apply_r_riscv_call_plt_rela,
	[R_RISCV_CALL] = apply_r_riscv_call_rela,
	[R_RISCV_RELAX] = apply_r_riscv_relax_rela,
	[R_RISCV_ALIGN] = apply_r_riscv_align_rela,
	[R_RISCV_ADD32] = apply_r_riscv_add32_rela,
	[R_RISCV_ADD64] = apply_r_riscv_add64_rela,
	[R_RISCV_SUB32] = apply_r_riscv_sub32_rela,
	[R_RISCV_SUB64] = apply_r_riscv_sub64_rela,
	};

	int apply_relocate_add(Elf_Shdr sechdrs, const char strtab,
	unsigned int symindex, unsigned int relsec,
	struct module *me)
	{
	Elf_Rela rel = (void ) sechdrs[relsec].sh_addr;
	int (handler)(struct module me, u32 *location, Elf_Addr v);
	Elf_Sym *sym;
	u32 *location;
	unsigned int i, type;
	Elf_Addr v;
	int res;

	pr_debug("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 */
	sym = (Elf_Sym *)sechdrs[symindex].sh_addr
	+ ELF_RISCV_R_SYM(rel[i].r_info);
	if (IS_ERR_VALUE(sym->st_value)) {
	/* Ignore unresolved weak symbol */
	if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
	continue;
	pr_warn("%s: Unknown symbol %s\n",
	me->name, strtab + sym->st_name);
	return -ENOENT;
	}

	type = ELF_RISCV_R_TYPE(rel[i].r_info);

	if (type < ARRAY_SIZE(reloc_handlers_rela))
	handler = reloc_handlers_rela[type];
	else
	handler = NULL;

	if (!handler) {
	pr_err("%s: Unknown relocation type %u\n",
	me->name, type);
	return -EINVAL;
	}

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

	if (type == R_RISCV_PCREL_LO12_I \|\| type == R_RISCV_PCREL_LO12_S) {
	unsigned int j;

	for (j = 0; j < sechdrs[relsec].sh_size / sizeof(*rel); j++) {
	unsigned long hi20_loc =
	sechdrs[sechdrs[relsec].sh_info].sh_addr
	+ rel[j].r_offset;
	u32 hi20_type = ELF_RISCV_R_TYPE(rel[j].r_info);

	/* Find the corresponding HI20 relocation entry */
	if (hi20_loc == sym->st_value
	&& (hi20_type == R_RISCV_PCREL_HI20
	\|\| hi20_type == R_RISCV_GOT_HI20)) {
	s32 hi20, lo12;
	Elf_Sym *hi20_sym =
	(Elf_Sym *)sechdrs[symindex].sh_addr
	+ ELF_RISCV_R_SYM(rel[j].r_info);
	unsigned long hi20_sym_val =
	hi20_sym->st_value
	+ rel[j].r_addend;

	/* Calculate lo12 */
	size_t offset = hi20_sym_val - hi20_loc;
	if (IS_ENABLED(CONFIG_MODULE_SECTIONS)
	&& hi20_type == R_RISCV_GOT_HI20) {
	offset = module_emit_got_entry(
	me, hi20_sym_val);
	offset = offset - hi20_loc;
	}
	hi20 = (offset + 0x800) & 0xfffff000;
	lo12 = offset - hi20;
	v = lo12;

	break;
	}
	}
	if (j == sechdrs[relsec].sh_size / sizeof(*rel)) {
	pr_err(
	"%s: Can not find HI20 relocation information\n",
	me->name);
	return -EINVAL;
	}
	}

	res = handler(me, location, v);
	if (res)
	return res;
	}

	return 0;
	}

	#if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
	void *module_alloc(unsigned long size)
	{
	return __vmalloc_node_range(size, 1, MODULES_VADDR,
	MODULES_END, GFP_KERNEL,
	PAGE_KERNEL, 0, NUMA_NO_NODE,
	__builtin_return_address(0));
	}
	#endif

	static const Elf_Shdr find_section(const Elf_Ehdr hdr,
	const Elf_Shdr *sechdrs,
	const char *name)
	{
	const Elf_Shdr s, se;
	const char secstrs = (void )hdr + sechdrs[hdr->e_shstrndx].sh_offset;

	for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) {
	if (strcmp(name, secstrs + s->sh_name) == 0)
	return s;
	}

	return NULL;
	}

	int module_finalize(const Elf_Ehdr *hdr,
	const Elf_Shdr *sechdrs,
	struct module *me)
	{
	const Elf_Shdr *s;

	s = find_section(hdr, sechdrs, ".alternative");
	if (s)
	apply_module_alternatives((void *)s->sh_addr, s->sh_size);

	return 0;
	}