DeforaOS/uKernel
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Work on relocations

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This commit is contained in:
Pierre Pronchery 2018-06-02 03:17:58 +02:00
parent 6d687d0959
commit 21470a46af
2 changed files with 47 additions and 17 deletions
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1
include/elf.h
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@ -261,6 +261,7 @@ typedef struct _Elf32_Rel
# define ELF64_R_SYM(info) ((info) >> 32) # define ELF64_R_SYM(info) ((info) >> 32)
# define ELF64_R_TYPE(info) ((info) & 0xffffffff) # define ELF64_R_TYPE(info) ((info) & 0xffffffff)
# define R_X86_64_NONE 0
# define R_X86_64_GLOB_DAT 6 # define R_X86_64_GLOB_DAT 6
# define R_X86_64_JUMP_SLOT 7 # define R_X86_64_JUMP_SLOT 7
# define R_X86_64_RELATIVE 8 # define R_X86_64_RELATIVE 8

63
src/drivers/boot/multiboot.c
View File

@ -22,7 +22,8 @@ static int _load_module_elf(ukMultibootMod * mod, unsigned char * elfclass,
static int _load_module_elf32(ukMultibootMod * mod, vaddr_t * entrypoint, static int _load_module_elf32(ukMultibootMod * mod, vaddr_t * entrypoint,
Elf32_Ehdr * ehdr); Elf32_Ehdr * ehdr);
static int _load_module_elf32_relocate(ukMultibootMod * mod, Elf32_Ehdr * ehdr); static int _load_module_elf32_relocate(ukMultibootMod * mod, Elf32_Ehdr * ehdr);
static int _load_module_elf32_relocate_arch(Elf32_Rela * rela, static int _load_module_elf32_relocate_arch(ukMultibootMod * mod,
Elf32_Shdr * shdr, Elf32_Rela * rela,
char const * strtab, size_t strtab_cnt, Elf32_Sym * sym); char const * strtab, size_t strtab_cnt, Elf32_Sym * sym);
static int _load_module_elf32_strtab(ukMultibootMod * mod, Elf32_Ehdr * ehdr, static int _load_module_elf32_strtab(ukMultibootMod * mod, Elf32_Ehdr * ehdr,
Elf32_Shdr * shdr, Elf32_Word index, Elf32_Shdr * shdr, Elf32_Word index,
@ -33,7 +34,8 @@ static int _load_module_elf32_symtab(ukMultibootMod * mod, Elf32_Ehdr * ehdr,
static int _load_module_elf64(ukMultibootMod * mod, vaddr_t * entrypoint, static int _load_module_elf64(ukMultibootMod * mod, vaddr_t * entrypoint,
Elf64_Ehdr * ehdr); Elf64_Ehdr * ehdr);
static int _load_module_elf64_relocate(ukMultibootMod * mod, Elf64_Ehdr * ehdr); static int _load_module_elf64_relocate(ukMultibootMod * mod, Elf64_Ehdr * ehdr);
static int _load_module_elf64_relocate_arch(Elf64_Rela * rela, static int _load_module_elf64_relocate_arch(ukMultibootMod * mod,
Elf64_Shdr * shdr, Elf64_Rela * rela,
char const * strtab, size_t strtab_cnt, Elf64_Sym * sym); char const * strtab, size_t strtab_cnt, Elf64_Sym * sym);
static int _load_module_elf64_strtab(ukMultibootMod * mod, Elf64_Ehdr * ehdr, static int _load_module_elf64_strtab(ukMultibootMod * mod, Elf64_Ehdr * ehdr,
Elf64_Shdr * shdr, Elf64_Word index, Elf64_Shdr * shdr, Elf64_Word index,
@ -175,23 +177,43 @@ static int _load_module_elf32_relocate(ukMultibootMod * mod, Elf32_Ehdr * ehdr)
memcpy(&rela, (char *)rel + j, shdr[i].sh_entsize); memcpy(&rela, (char *)rel + j, shdr[i].sh_entsize);
sym = (ELF32_R_SYM(rela.r_info) < symtab_cnt) sym = (ELF32_R_SYM(rela.r_info) < symtab_cnt)
? &symtab[ELF32_R_SYM(rela.r_info)] : NULL; ? &symtab[ELF32_R_SYM(rela.r_info)] : NULL;
if(_load_module_elf32_relocate_arch(&rela, strtab, if(_load_module_elf32_relocate_arch(mod,
strtab_cnt, sym) != 0) shdr[i].sh_info < ehdr->e_shnum
? &shdr[shdr[i].sh_info] : NULL,
&rela, strtab, strtab_cnt,
sym) != 0)
return -1; return -1;
} }
} }
return 0; return 0;
} }
static int _load_module_elf32_relocate_arch(Elf32_Rela * rela, static int _load_module_elf32_relocate_arch(ukMultibootMod * mod,
Elf32_Shdr * shdr, Elf32_Rela * rela,
char const * strtab, size_t strtab_cnt, Elf32_Sym * sym) char const * strtab, size_t strtab_cnt, Elf32_Sym * sym)
{ {
#if defined(__i386__) #if defined(__i386__)
Elf32_Addr * addr;
addr = (Elf32_Addr *)(mod->start + (shdr != NULL ? shdr->sh_offset : 0)
+ rela->r_offset);
switch(ELF32_R_TYPE(rela->r_info)) switch(ELF32_R_TYPE(rela->r_info))
{ {
case R_386_32: case R_386_32: /* S + A */
case R_386_PC32: *addr = sym->st_value + rela->r_addend;
/* FIXME implement */ break;
case R_386_GLOB_DAT: /* S */
case R_386_JMP_SLOT: /* S */
*addr = sym->st_value + rela->r_addend;
break;
case R_386_NONE:
break;
case R_386_PC32: /* S + A - P */
*addr = sym->st_value + rela->r_addend
- (shdr != NULL ? shdr->sh_offset : 0);
break;
case R_386_RELATIVE: /* B + A */
*addr = mod->start + rela->r_addend;
break; break;
default: default:
printf("%u: Relocation not supported\n", printf("%u: Relocation not supported\n",
@ -308,29 +330,36 @@ static int _load_module_elf64_relocate(ukMultibootMod * mod, Elf64_Ehdr * ehdr)
memcpy(&rela, (char *)rel + j, shdr[i].sh_entsize); memcpy(&rela, (char *)rel + j, shdr[i].sh_entsize);
sym = (ELF64_R_SYM(rela.r_info) < symtab_cnt) sym = (ELF64_R_SYM(rela.r_info) < symtab_cnt)
? &symtab[ELF64_R_SYM(rela.r_info)] : NULL; ? &symtab[ELF64_R_SYM(rela.r_info)] : NULL;
if(_load_module_elf64_relocate_arch(&rela, strtab, if(_load_module_elf64_relocate_arch(mod,
strtab_cnt, sym) != 0) shdr[i].sh_info < ehdr->e_shnum
? &shdr[shdr[i].sh_info] : NULL,
&rela, strtab, strtab_cnt,
sym) != 0)
return -1; return -1;
} }
} }
return 0; return 0;
} }
static int _load_module_elf64_relocate_arch(Elf64_Rela * rela, static int _load_module_elf64_relocate_arch(ukMultibootMod * mod,
Elf64_Shdr * shdr, Elf64_Rela * rela,
char const * strtab, size_t strtab_cnt, Elf64_Sym * sym) char const * strtab, size_t strtab_cnt, Elf64_Sym * sym)
{ {
#if defined(__i386__) #if defined(__i386__)
Elf64_Addr * addr; Elf64_Addr * addr;
addr = (Elf64_Addr *)(mod->start + (shdr != NULL ? shdr->sh_offset : 0)
+ rela->r_offset);
switch(ELF64_R_TYPE(rela->r_info)) switch(ELF64_R_TYPE(rela->r_info))
{ {
case R_X86_64_RELATIVE: case R_X86_64_GLOB_DAT: /* S */
case R_X86_64_GLOB_DAT: case R_X86_64_JUMP_SLOT:/* S */
/* FIXME implement */ *addr = sym->st_value + rela->r_addend;
break; break;
case R_X86_64_JUMP_SLOT: case R_X86_64_NONE:
addr = (Elf64_Addr)rela->r_offset; break;
*addr = rela->r_addend; case R_X86_64_RELATIVE: /* B + A */
*addr = mod->start + rela->r_addend;
break; break;
default: default:
printf("%u: Relocation not supported\n", printf("%u: Relocation not supported\n",