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114 lines
2.9 KiB
114 lines
2.9 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
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/* Copyright (C) 2017 Andes Technology Corporation */ |
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#ifndef _ASM_RISCV_MODULE_H |
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#define _ASM_RISCV_MODULE_H |
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#include <asm-generic/module.h> |
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struct module; |
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unsigned long module_emit_got_entry(struct module *mod, unsigned long val); |
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unsigned long module_emit_plt_entry(struct module *mod, unsigned long val); |
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#ifdef CONFIG_MODULE_SECTIONS |
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struct mod_section { |
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Elf_Shdr *shdr; |
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int num_entries; |
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int max_entries; |
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}; |
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struct mod_arch_specific { |
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struct mod_section got; |
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struct mod_section plt; |
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struct mod_section got_plt; |
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}; |
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struct got_entry { |
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unsigned long symbol_addr; /* the real variable address */ |
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}; |
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static inline struct got_entry emit_got_entry(unsigned long val) |
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{ |
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return (struct got_entry) {val}; |
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} |
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static inline struct got_entry *get_got_entry(unsigned long val, |
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const struct mod_section *sec) |
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{ |
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struct got_entry *got = (struct got_entry *)(sec->shdr->sh_addr); |
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int i; |
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for (i = 0; i < sec->num_entries; i++) { |
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if (got[i].symbol_addr == val) |
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return &got[i]; |
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} |
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return NULL; |
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} |
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struct plt_entry { |
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/* |
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* Trampoline code to real target address. The return address |
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* should be the original (pc+4) before entring plt entry. |
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*/ |
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u32 insn_auipc; /* auipc t0, 0x0 */ |
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u32 insn_ld; /* ld t1, 0x10(t0) */ |
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u32 insn_jr; /* jr t1 */ |
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}; |
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#define OPC_AUIPC 0x0017 |
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#define OPC_LD 0x3003 |
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#define OPC_JALR 0x0067 |
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#define REG_T0 0x5 |
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#define REG_T1 0x6 |
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static inline struct plt_entry emit_plt_entry(unsigned long val, |
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unsigned long plt, |
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unsigned long got_plt) |
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{ |
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/* |
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* U-Type encoding: |
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* +------------+----------+----------+ |
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* | imm[31:12] | rd[11:7] | opc[6:0] | |
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* +------------+----------+----------+ |
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* |
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* I-Type encoding: |
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* +------------+------------+--------+----------+----------+ |
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* | imm[31:20] | rs1[19:15] | funct3 | rd[11:7] | opc[6:0] | |
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* +------------+------------+--------+----------+----------+ |
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* |
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*/ |
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unsigned long offset = got_plt - plt; |
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u32 hi20 = (offset + 0x800) & 0xfffff000; |
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u32 lo12 = (offset - hi20); |
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return (struct plt_entry) { |
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OPC_AUIPC | (REG_T0 << 7) | hi20, |
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OPC_LD | (lo12 << 20) | (REG_T0 << 15) | (REG_T1 << 7), |
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OPC_JALR | (REG_T1 << 15) |
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}; |
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} |
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static inline int get_got_plt_idx(unsigned long val, const struct mod_section *sec) |
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{ |
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struct got_entry *got_plt = (struct got_entry *)sec->shdr->sh_addr; |
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int i; |
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for (i = 0; i < sec->num_entries; i++) { |
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if (got_plt[i].symbol_addr == val) |
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return i; |
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} |
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return -1; |
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} |
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static inline struct plt_entry *get_plt_entry(unsigned long val, |
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const struct mod_section *sec_plt, |
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const struct mod_section *sec_got_plt) |
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{ |
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struct plt_entry *plt = (struct plt_entry *)sec_plt->shdr->sh_addr; |
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int got_plt_idx = get_got_plt_idx(val, sec_got_plt); |
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if (got_plt_idx >= 0) |
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return plt + got_plt_idx; |
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else |
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return NULL; |
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} |
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#endif /* CONFIG_MODULE_SECTIONS */ |
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#endif /* _ASM_RISCV_MODULE_H */
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