/* -*- mode:c; c-file-style:"k&r"; c-basic-offset: 4; tab-width:4; indent-tabs-mode:nil; mode:auto-fill; fill-column:78; -*- */
/* vim: set ts=4 sw=4 et tw=78 fo=cqt wm=0: */
/* Copyright (C) 2014 OSCAR lab, Stony Brook University
This file is part of Graphene Library OS.
Graphene Library OS is free software: you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.
Graphene Library OS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see . */
/*
* db_rtld.c
*
* This file contains utilities to load ELF binaries into the memory
* and link them against each other.
* The source code in this file is imported and modified from the GNU C
* Library.
*/
#include "pal_defs.h"
#include "pal_linux_defs.h"
#include "pal.h"
#include "pal_internal.h"
#include "pal_linux.h"
#include "pal_debug.h"
#include "pal_error.h"
#include "pal_security.h"
#include "pal_rtld.h"
#include "api.h"
#include
#include
#include
#include "elf-x86_64.h"
void _DkDebugAddMap (struct link_map * map)
{
const ElfW(Ehdr) * ehdr = (void *) map->l_map_start;
int shdrsz = sizeof(ElfW(Shdr)) * ehdr->e_shnum;
ElfW(Shdr) * shdr = NULL;
ElfW(Phdr) * phdr = (void *) (map->l_map_start + ehdr->e_phoff);
const ElfW(Phdr) * ph;
int fd = ocall_open(map->l_name, O_RDONLY, 0);
if (fd < 0)
return;
for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
if (ph->p_type == PT_LOAD &&
ehdr->e_shoff >= ph->p_offset &&
ehdr->e_shoff < ph->p_offset + ph->p_filesz) {
shdr = (void *) map->l_addr + ph->p_vaddr +
(ehdr->e_shoff - ph->p_offset);
break;
}
if (!shdr) {
shdr = __alloca(shdrsz);
unsigned long s = ALLOC_ALIGNDOWN(ehdr->e_shoff);
unsigned long e = ALLOC_ALIGNUP(ehdr->e_shoff + shdrsz);
void * umem;
ocall_map_untrusted(fd, s, e - s, PROT_READ, &umem);
memcpy(shdr, umem + ehdr->e_shoff - s, shdrsz);
ocall_unmap_untrusted(umem, e - s);
}
ElfW(Shdr) * shdrend = (void *) shdr + shdrsz;
int shstroff = shdr[ehdr->e_shstrndx].sh_offset;
size_t shstrsz = shdr[ehdr->e_shstrndx].sh_size;
const char * shstrtab = NULL;
for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
if (ph->p_type == PT_LOAD &&
shstroff >= ph->p_offset &&
shstroff < ph->p_offset + ph->p_filesz) {
shstrtab = (void *) map->l_addr + ph->p_vaddr +
(shstroff - ph->p_offset);
break;
}
if (!shstrtab) {
shstrtab = __alloca(shstrsz);
unsigned long s = ALLOC_ALIGNDOWN(shstroff);
unsigned long e = ALLOC_ALIGNUP(shstroff + shstrsz);
void * umem;
ocall_map_untrusted(fd, s, e - s, PROT_READ, &umem);
memcpy((void *) shstrtab, umem + shstroff - s, shstrsz);
ocall_unmap_untrusted(umem, e - s);
}
ocall_close(fd);
ElfW(Addr) text_addr = 0;
for (ElfW(Shdr) * s = shdr ; s < shdrend ; s++)
if (strcmp_static(shstrtab + s->sh_name, ".text")) {
text_addr = map->l_addr + s->sh_addr;
break;
}
if (!text_addr)
return;
#define BUFFER_LENGTH 4096
char buffer[BUFFER_LENGTH], * ptr = buffer;
snprintf(ptr, BUFFER_LENGTH - (ptr - buffer),
"add-symbol-file %s 0x%016llx -readnow", map->l_name, text_addr);
ptr += strlen(ptr);
for (ElfW(Shdr) * s = shdr ; s < shdrend ; s++) {
if (!s->sh_name || !s->sh_addr)
continue;
if (strcmp_static(shstrtab + s->sh_name, ".text"))
continue;
if (s->sh_type == SHT_NULL)
continue;
if (strpartcmp_static(shstrtab + s->sh_name, ".debug_"))
continue;
snprintf(ptr, BUFFER_LENGTH - (ptr - buffer),
" -s %s 0x%016llx", shstrtab + s->sh_name,
map->l_addr + s->sh_addr);
ptr += strlen(ptr);
}
ocall_load_debug(buffer);
}
void _DkDebugDelMap (struct link_map * map)
{
char buffer[BUFFER_LENGTH];
snprintf(buffer, BUFFER_LENGTH, "remove-symbol-file %s", map->l_name);
ocall_load_debug(buffer);
}
void setup_elf_hash (struct link_map *map);
extern void * section_text, * section_rodata, * section_dynamic,
* section_data, * section_bss;
void setup_pal_map (struct link_map * pal_map)
{
const ElfW(Ehdr) * header = (void *) pal_map->l_addr;
pal_map->l_real_ld = pal_map->l_ld = (void *) elf_machine_dynamic();
pal_map->l_type = OBJECT_RTLD;
pal_map->l_entry = header->e_entry;
pal_map->l_phdr = (void *) (pal_map->l_addr + header->e_phoff);
pal_map->l_phnum = header->e_phnum;
setup_elf_hash(pal_map);
char buffer[BUFFER_LENGTH];
snprintf(buffer, BUFFER_LENGTH,
"add-symbol-file %s 0x%016llx -readnow -s .rodata 0x%016llx "
"-s .dynamic 0x%016llx -s .data 0x%016llx -s .bss 0x%016llx",
pal_map->l_name,
§ion_text, §ion_rodata, §ion_dynamic,
§ion_data, §ion_bss);
ocall_load_debug(buffer);
pal_map->l_prev = pal_map->l_next = NULL;
loaded_maps = pal_map;
}
ElfW(Addr) resolve_rtld (const char * sym_name)
{
/* We are not using this, because in Linux we can rely on
rtld_map to directly lookup symbols */
return 0;
}