459 lines
13 KiB
C
459 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Author: Hanlu Li <lihanlu@loongson.cn>
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* Huacai Chen <chenhuacai@loongson.cn>
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*
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* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
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*/
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#define pr_fmt(fmt) "kmod: " fmt
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#include <linux/moduleloader.h>
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#include <linux/elf.h>
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#include <linux/mm.h>
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#include <linux/numa.h>
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#include <linux/vmalloc.h>
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#include <linux/slab.h>
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#include <linux/fs.h>
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#include <linux/string.h>
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#include <linux/kernel.h>
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static int rela_stack_push(s64 stack_value, s64 *rela_stack, size_t *rela_stack_top)
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{
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if (*rela_stack_top >= RELA_STACK_DEPTH)
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return -ENOEXEC;
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rela_stack[(*rela_stack_top)++] = stack_value;
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pr_debug("%s stack_value = 0x%llx\n", __func__, stack_value);
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return 0;
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}
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static int rela_stack_pop(s64 *stack_value, s64 *rela_stack, size_t *rela_stack_top)
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{
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if (*rela_stack_top == 0)
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return -ENOEXEC;
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*stack_value = rela_stack[--(*rela_stack_top)];
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pr_debug("%s stack_value = 0x%llx\n", __func__, *stack_value);
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return 0;
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}
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static int apply_r_larch_none(struct module *mod, u32 *location, Elf_Addr v,
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s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
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{
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return 0;
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}
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static int apply_r_larch_error(struct module *me, u32 *location, Elf_Addr v,
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s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
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{
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pr_err("%s: Unsupport relocation type %u, please add its support.\n", me->name, type);
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return -EINVAL;
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}
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static int apply_r_larch_32(struct module *mod, u32 *location, Elf_Addr v,
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s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
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{
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*location = v;
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return 0;
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}
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static int apply_r_larch_64(struct module *mod, u32 *location, Elf_Addr v,
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s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
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{
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*(Elf_Addr *)location = v;
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return 0;
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}
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static int apply_r_larch_sop_push_pcrel(struct module *mod, u32 *location, Elf_Addr v,
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s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
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{
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return rela_stack_push(v - (u64)location, rela_stack, rela_stack_top);
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}
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static int apply_r_larch_sop_push_absolute(struct module *mod, u32 *location, Elf_Addr v,
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s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
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{
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return rela_stack_push(v, rela_stack, rela_stack_top);
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}
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static int apply_r_larch_sop_push_dup(struct module *mod, u32 *location, Elf_Addr v,
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s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
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{
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int err = 0;
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s64 opr1;
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err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
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if (err)
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return err;
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err = rela_stack_push(opr1, rela_stack, rela_stack_top);
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if (err)
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return err;
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err = rela_stack_push(opr1, rela_stack, rela_stack_top);
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if (err)
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return err;
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return 0;
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}
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static int apply_r_larch_sop_push_plt_pcrel(struct module *mod, u32 *location, Elf_Addr v,
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s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
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{
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ptrdiff_t offset = (void *)v - (void *)location;
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if (offset >= SZ_128M)
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v = module_emit_plt_entry(mod, v);
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if (offset < -SZ_128M)
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v = module_emit_plt_entry(mod, v);
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return apply_r_larch_sop_push_pcrel(mod, location, v, rela_stack, rela_stack_top, type);
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}
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static int apply_r_larch_sop(struct module *mod, u32 *location, Elf_Addr v,
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s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
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{
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int err = 0;
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s64 opr1, opr2, opr3;
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if (type == R_LARCH_SOP_IF_ELSE) {
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err = rela_stack_pop(&opr3, rela_stack, rela_stack_top);
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if (err)
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return err;
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}
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err = rela_stack_pop(&opr2, rela_stack, rela_stack_top);
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if (err)
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return err;
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err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
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if (err)
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return err;
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switch (type) {
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case R_LARCH_SOP_AND:
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err = rela_stack_push(opr1 & opr2, rela_stack, rela_stack_top);
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break;
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case R_LARCH_SOP_ADD:
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err = rela_stack_push(opr1 + opr2, rela_stack, rela_stack_top);
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break;
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case R_LARCH_SOP_SUB:
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err = rela_stack_push(opr1 - opr2, rela_stack, rela_stack_top);
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break;
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case R_LARCH_SOP_SL:
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err = rela_stack_push(opr1 << opr2, rela_stack, rela_stack_top);
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break;
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case R_LARCH_SOP_SR:
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err = rela_stack_push(opr1 >> opr2, rela_stack, rela_stack_top);
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break;
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case R_LARCH_SOP_IF_ELSE:
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err = rela_stack_push(opr1 ? opr2 : opr3, rela_stack, rela_stack_top);
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break;
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default:
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pr_err("%s: Unsupport relocation type %u\n", mod->name, type);
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return -EINVAL;
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}
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return err;
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}
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static int apply_r_larch_sop_imm_field(struct module *mod, u32 *location, Elf_Addr v,
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s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
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{
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int err = 0;
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s64 opr1;
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union loongarch_instruction *insn = (union loongarch_instruction *)location;
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err = rela_stack_pop(&opr1, rela_stack, rela_stack_top);
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if (err)
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return err;
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switch (type) {
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case R_LARCH_SOP_POP_32_U_10_12:
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if (!unsigned_imm_check(opr1, 12))
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goto overflow;
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/* (*(uint32_t *) PC) [21 ... 10] = opr [11 ... 0] */
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insn->reg2i12_format.immediate = opr1 & 0xfff;
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return 0;
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case R_LARCH_SOP_POP_32_S_10_12:
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if (!signed_imm_check(opr1, 12))
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goto overflow;
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insn->reg2i12_format.immediate = opr1 & 0xfff;
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return 0;
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case R_LARCH_SOP_POP_32_S_10_16:
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if (!signed_imm_check(opr1, 16))
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goto overflow;
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insn->reg2i16_format.immediate = opr1 & 0xffff;
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return 0;
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case R_LARCH_SOP_POP_32_S_10_16_S2:
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if (opr1 % 4)
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goto unaligned;
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if (!signed_imm_check(opr1, 18))
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goto overflow;
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insn->reg2i16_format.immediate = (opr1 >> 2) & 0xffff;
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return 0;
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case R_LARCH_SOP_POP_32_S_5_20:
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if (!signed_imm_check(opr1, 20))
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goto overflow;
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insn->reg1i20_format.immediate = (opr1) & 0xfffff;
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return 0;
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case R_LARCH_SOP_POP_32_S_0_5_10_16_S2:
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if (opr1 % 4)
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goto unaligned;
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if (!signed_imm_check(opr1, 23))
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goto overflow;
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opr1 >>= 2;
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insn->reg1i21_format.immediate_l = opr1 & 0xffff;
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insn->reg1i21_format.immediate_h = (opr1 >> 16) & 0x1f;
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return 0;
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case R_LARCH_SOP_POP_32_S_0_10_10_16_S2:
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if (opr1 % 4)
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goto unaligned;
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if (!signed_imm_check(opr1, 28))
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goto overflow;
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opr1 >>= 2;
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insn->reg0i26_format.immediate_l = opr1 & 0xffff;
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insn->reg0i26_format.immediate_h = (opr1 >> 16) & 0x3ff;
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return 0;
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case R_LARCH_SOP_POP_32_U:
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if (!unsigned_imm_check(opr1, 32))
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goto overflow;
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/* (*(uint32_t *) PC) = opr */
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*location = (u32)opr1;
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return 0;
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default:
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pr_err("%s: Unsupport relocation type %u\n", mod->name, type);
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return -EINVAL;
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}
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overflow:
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pr_err("module %s: opr1 = 0x%llx overflow! dangerous %s (%u) relocation\n",
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mod->name, opr1, __func__, type);
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return -ENOEXEC;
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unaligned:
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pr_err("module %s: opr1 = 0x%llx unaligned! dangerous %s (%u) relocation\n",
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mod->name, opr1, __func__, type);
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return -ENOEXEC;
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}
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static int apply_r_larch_add_sub(struct module *mod, u32 *location, Elf_Addr v,
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s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
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{
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switch (type) {
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case R_LARCH_ADD32:
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*(s32 *)location += v;
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return 0;
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case R_LARCH_ADD64:
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*(s64 *)location += v;
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return 0;
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case R_LARCH_SUB32:
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*(s32 *)location -= v;
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return 0;
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case R_LARCH_SUB64:
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*(s64 *)location -= v;
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return 0;
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default:
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pr_err("%s: Unsupport relocation type %u\n", mod->name, type);
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return -EINVAL;
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}
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}
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static int apply_r_larch_b26(struct module *mod, u32 *location, Elf_Addr v,
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s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
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{
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ptrdiff_t offset = (void *)v - (void *)location;
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union loongarch_instruction *insn = (union loongarch_instruction *)location;
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if (offset >= SZ_128M)
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v = module_emit_plt_entry(mod, v);
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if (offset < -SZ_128M)
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v = module_emit_plt_entry(mod, v);
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offset = (void *)v - (void *)location;
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if (offset & 3) {
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pr_err("module %s: jump offset = 0x%llx unaligned! dangerous R_LARCH_B26 (%u) relocation\n",
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mod->name, (long long)offset, type);
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return -ENOEXEC;
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}
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if (!signed_imm_check(offset, 28)) {
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pr_err("module %s: jump offset = 0x%llx overflow! dangerous R_LARCH_B26 (%u) relocation\n",
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mod->name, (long long)offset, type);
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return -ENOEXEC;
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}
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offset >>= 2;
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insn->reg0i26_format.immediate_l = offset & 0xffff;
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insn->reg0i26_format.immediate_h = (offset >> 16) & 0x3ff;
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return 0;
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}
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static int apply_r_larch_pcala(struct module *mod, u32 *location, Elf_Addr v,
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s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
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{
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union loongarch_instruction *insn = (union loongarch_instruction *)location;
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/* Use s32 for a sign-extension deliberately. */
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s32 offset_hi20 = (void *)((v + 0x800) & ~0xfff) -
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(void *)((Elf_Addr)location & ~0xfff);
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Elf_Addr anchor = (((Elf_Addr)location) & ~0xfff) + offset_hi20;
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ptrdiff_t offset_rem = (void *)v - (void *)anchor;
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switch (type) {
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case R_LARCH_PCALA_LO12:
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insn->reg2i12_format.immediate = v & 0xfff;
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break;
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case R_LARCH_PCALA_HI20:
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v = offset_hi20 >> 12;
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insn->reg1i20_format.immediate = v & 0xfffff;
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break;
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case R_LARCH_PCALA64_LO20:
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v = offset_rem >> 32;
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insn->reg1i20_format.immediate = v & 0xfffff;
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break;
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case R_LARCH_PCALA64_HI12:
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v = offset_rem >> 52;
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insn->reg2i12_format.immediate = v & 0xfff;
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break;
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default:
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pr_err("%s: Unsupport relocation type %u\n", mod->name, type);
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return -EINVAL;
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}
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return 0;
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}
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static int apply_r_larch_got_pc(struct module *mod, u32 *location, Elf_Addr v,
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s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
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{
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Elf_Addr got = module_emit_got_entry(mod, v);
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if (!got)
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return -EINVAL;
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switch (type) {
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case R_LARCH_GOT_PC_LO12:
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type = R_LARCH_PCALA_LO12;
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break;
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case R_LARCH_GOT_PC_HI20:
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type = R_LARCH_PCALA_HI20;
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break;
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default:
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pr_err("%s: Unsupport relocation type %u\n", mod->name, type);
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return -EINVAL;
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}
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return apply_r_larch_pcala(mod, location, got, rela_stack, rela_stack_top, type);
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}
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/*
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* reloc_handlers_rela() - Apply a particular relocation to a module
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* @mod: the module to apply the reloc to
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* @location: the address at which the reloc is to be applied
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* @v: the value of the reloc, with addend for RELA-style
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* @rela_stack: the stack used for store relocation info, LOCAL to THIS module
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* @rela_stac_top: where the stack operation(pop/push) applies to
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*
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* Return: 0 upon success, else -ERRNO
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*/
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typedef int (*reloc_rela_handler)(struct module *mod, u32 *location, Elf_Addr v,
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s64 *rela_stack, size_t *rela_stack_top, unsigned int type);
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/* The handlers for known reloc types */
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static reloc_rela_handler reloc_rela_handlers[] = {
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[R_LARCH_NONE ... R_LARCH_RELAX] = apply_r_larch_error,
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[R_LARCH_NONE] = apply_r_larch_none,
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[R_LARCH_32] = apply_r_larch_32,
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[R_LARCH_64] = apply_r_larch_64,
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[R_LARCH_MARK_LA] = apply_r_larch_none,
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[R_LARCH_MARK_PCREL] = apply_r_larch_none,
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[R_LARCH_SOP_PUSH_PCREL] = apply_r_larch_sop_push_pcrel,
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[R_LARCH_SOP_PUSH_ABSOLUTE] = apply_r_larch_sop_push_absolute,
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[R_LARCH_SOP_PUSH_DUP] = apply_r_larch_sop_push_dup,
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[R_LARCH_SOP_PUSH_PLT_PCREL] = apply_r_larch_sop_push_plt_pcrel,
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[R_LARCH_SOP_SUB ... R_LARCH_SOP_IF_ELSE] = apply_r_larch_sop,
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[R_LARCH_SOP_POP_32_S_10_5 ... R_LARCH_SOP_POP_32_U] = apply_r_larch_sop_imm_field,
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[R_LARCH_ADD32 ... R_LARCH_SUB64] = apply_r_larch_add_sub,
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[R_LARCH_B26] = apply_r_larch_b26,
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[R_LARCH_PCALA_HI20...R_LARCH_PCALA64_HI12] = apply_r_larch_pcala,
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[R_LARCH_GOT_PC_HI20...R_LARCH_GOT_PC_LO12] = apply_r_larch_got_pc,
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};
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int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
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unsigned int symindex, unsigned int relsec,
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struct module *mod)
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{
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int i, err;
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unsigned int type;
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s64 rela_stack[RELA_STACK_DEPTH];
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size_t rela_stack_top = 0;
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reloc_rela_handler handler;
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void *location;
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Elf_Addr v;
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Elf_Sym *sym;
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Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr;
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pr_debug("%s: Applying relocate section %u to %u\n", __func__, relsec,
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sechdrs[relsec].sh_info);
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rela_stack_top = 0;
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for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
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/* This is where to make the change */
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location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr + rel[i].r_offset;
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/* This is the symbol it is referring to */
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sym = (Elf_Sym *)sechdrs[symindex].sh_addr + ELF_R_SYM(rel[i].r_info);
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if (IS_ERR_VALUE(sym->st_value)) {
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/* Ignore unresolved weak symbol */
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if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
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continue;
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pr_warn("%s: Unknown symbol %s\n", mod->name, strtab + sym->st_name);
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return -ENOENT;
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}
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type = ELF_R_TYPE(rel[i].r_info);
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if (type < ARRAY_SIZE(reloc_rela_handlers))
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handler = reloc_rela_handlers[type];
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else
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handler = NULL;
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if (!handler) {
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pr_err("%s: Unknown relocation type %u\n", mod->name, type);
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return -EINVAL;
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}
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pr_debug("type %d st_value %llx r_addend %llx loc %llx\n",
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(int)ELF_R_TYPE(rel[i].r_info),
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sym->st_value, rel[i].r_addend, (u64)location);
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v = sym->st_value + rel[i].r_addend;
|
|
err = handler(mod, location, v, rela_stack, &rela_stack_top, type);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
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));
|
|
}
|