DeforaOS/Loader
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Implement relocations in a single function

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This commit is contained in:
Pierre Pronchery 2021-10-05 01:37:01 +02:00
parent b3170af3e2
commit 8e93085060
1 changed files with 13 additions and 51 deletions
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64
src/loader.c
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@ -57,8 +57,8 @@ static int _loader_do(int fd, char const * filename, int argc, char * argv[]);
static int _do_phdr(int fd, char const * filename, Elf_Ehdr * ehdr);
static size_t _do_phdr_align_bits(unsigned long align);
static int _do_shdr(int fd, char const * filename, Elf_Ehdr * ehdr);
static int _do_shdr_rel(int fd, char const * filename, Elf_Shdr * shdr);
static int _do_shdr_rela(int fd, char const * filename, Elf_Shdr * shdr);
static int _do_shdr_rela(int fd, char const * filename, Elf_Shdr * shdr,
size_t entsize);
int loader(char const * filename, int argc, char * argv[])
{
@ -230,10 +230,10 @@ static int _do_shdr(int fd, char const * filename, Elf_Ehdr * ehdr)
(unsigned long)shdr.sh_addralign,
(unsigned long)shdr.sh_entsize);
#endif
if(shdr.sh_type == SHT_REL)
ret = _do_shdr_rel(fd, filename, &shdr);
else if(shdr.sh_type == SHT_RELA)
ret = _do_shdr_rela(fd, filename, &shdr);
if(shdr.sh_type == SHT_REL
|| shdr.sh_type == SHT_RELA)
ret = _do_shdr_rela(fd, filename, &shdr,
shdr.sh_entsize);
else
continue;
if(ret != 0)
@ -245,60 +245,22 @@ static int _do_shdr(int fd, char const * filename, Elf_Ehdr * ehdr)
return 0;
}
static int _do_shdr_rel(int fd, char const * filename, Elf_Shdr * shdr)
{
Elf_Rel rel;
size_t i;
if(shdr->sh_entsize != sizeof(rel))
return _error(2, "%s: %s", filename,
"Invalid or unsupported ELF file");
if(lseek(fd, shdr->sh_offset, SEEK_SET) != (off_t)shdr->sh_offset)
return _error(2, "%s: %s", filename, strerror(errno));
for(i = 0; i + sizeof(rel) < shdr->sh_size; i += sizeof(rel))
{
if(read(fd, &rel, sizeof(rel)) != sizeof(rel))
return _error(2, "%s: %s", filename,
"Invalid or unsupported ELF file");
#ifdef DEBUG
fprintf(stderr, "DEBUG: %zu: r_offset=%#lx r_type=%lu \n", i,
(unsigned long)rel.r_offset,
(unsigned long)ELF_R_TYPE(rel.r_info));
#endif
switch(ELF_R_TYPE(rel.r_info))
{
#if defined(__amd64__)
case R_X86_64_NONE:
break;
case R_X86_64_GLOB_DAT:
case R_X86_64_JUMP_SLOT:
case R_X86_64_RELATIVE:
/* FIXME implement */
break;
#endif
default:
return _error(2, "%s: %lu:"
" Unsupported relocation\n",
filename,
ELF_R_TYPE(rel.r_info));
}
}
return 0;
}
static int _do_shdr_rela(int fd, char const * filename, Elf_Shdr * shdr)
static int _do_shdr_rela(int fd, char const * filename, Elf_Shdr * shdr,
size_t entsize)
{
Elf_Rela rela;
size_t i;
if(shdr->sh_entsize != sizeof(rela))
rela.r_addend = 0;
/* TODO test according to sh_type */
if(entsize != sizeof(rela) && entsize != sizeof(Elf_Rel))
return _error(2, "%s: %s", filename,
"Invalid or unsupported ELF file");
if(lseek(fd, shdr->sh_offset, SEEK_SET) != (off_t)shdr->sh_offset)
return _error(2, "%s: %s", filename, strerror(errno));
for(i = 0; i + sizeof(rela) < shdr->sh_size; i += sizeof(rela))
for(i = 0; i + entsize < shdr->sh_size; i += entsize)
{
if(read(fd, &rela, sizeof(rela)) != sizeof(rela))
if(read(fd, &rela, entsize) != (ssize_t)entsize)
return _error(2, "%s: %s", filename,
"Invalid or unsupported ELF file");
#ifdef DEBUG