diff options
| -rw-r--r-- | ldso/ldso/boot1.c | 1214 | ||||
| -rw-r--r-- | ldso/ldso/ldso.c | 12 |
2 files changed, 5 insertions, 1221 deletions
diff --git a/ldso/ldso/boot1.c b/ldso/ldso/boot1.c deleted file mode 100644 index e61276cce..000000000 --- a/ldso/ldso/boot1.c +++ /dev/null @@ -1,1214 +0,0 @@ -/* Run an ELF binary on a linux system. - - Copyright (C) 1993-1996, Eric Youngdale. - - This program 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 2, or (at your option) - any later version. - - This program 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, write to the Free Software - Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ - - - -/* Program to load an ELF binary on a linux system, and run it. - * References to symbols in sharable libraries can be resolved by - * an ELF sharable library. */ - -/* Disclaimer: I have never seen any AT&T source code for SVr4, nor have - I ever taken any courses on internals. This program was developed using - information available through the book "UNIX SYSTEM V RELEASE 4, - Programmers guide: Ansi C and Programming Support Tools", which did - a more than adequate job of explaining everything required to get this - working. */ - -/* - * The main trick with this program is that initially, we ourselves are not - * dynamicly linked. This means that we cannot access any global variables - * since the GOT is initialized by the linker assuming a virtual address of 0, - * and we cannot call any functions since the PLT is not initialized at all - * (it will tend to want to call the dynamic linker - * - * There are further restrictions - we cannot use large switch statements, - * since the compiler generates tables of addresses and jumps through them. - * We can use inline functions, because these do not transfer control to - * a new address, but they must be static so that they are not exported - * from the modules. We cannot use normal syscall stubs, because these - * all reference the errno global variable which is not yet initialized. - * We can use all of the local stack variables that we want, since these - * are all referenced to %ebp or %esp. - * - * Life is further complicated by the fact that initially we do not want - * to do a complete dynamic linking. We want to allow the user to supply - * new functions replacing some of the library versions, and until we have - * the list of modules that we should search set up, we do not want to do - * any of this. Thus I have chosen to only perform the relocations for - * variables that start with "_dl_" since ANSI specifies that the user is - * not supposed to redefine any of these variables. - * - * Fortunately, the linker itself leaves a few clues lying around, and - * when the kernel starts the image, there are a few further clues. - * First of all, there is information buried on the stack that the kernel - * leaves, which includes information about the load address that the - * program interpreter was loaded at, the number of sections, the address - * the application was loaded at and so forth. Here this information - * is stored in the array dl_info, and the indicies are taken from the - * file /usr/include/sys/auxv.h on any SVr4 system. - * - * The linker itself leaves a pointer to the .dynamic section in the first - * slot of the GOT, and as it turns out, %ebx points to ghe GOT when - * you are using PIC code, so we just dereference this to get the address - * of the dynamic sections. - * - * Typically you must load all text pages as writable so that dynamic linking - * can succeed. The kernel under SVr4 loads these as R/O, so we must call - * mprotect to change the protections. Once we are done, we should set these - * back again, so the desired behavior is achieved. Under linux there is - * currently no mprotect function in the distribution kernel (although - * someone has alpha patches), so for now everything is loaded writable. - * - * We do not have access to malloc and friends at the initial stages of dynamic - * linking, and it would be handy to have some scratchpad memory available for - * use as we set things up. We mmap one page of scratch space, and have a - * simple _dl_malloc that uses this memory. This is a good thing, since we do - * not want to use the same memory pool as malloc anyway - esp if the user - * redefines malloc to do something funky. - * - * Our first task is to perform a minimal linking so that we can call other - * portions of the dynamic linker. Once we have done this, we then build - * the list of modules that the application requires, using LD_LIBRARY_PATH - * if this is not a suid program (/usr/lib otherwise). Once this is done, - * we can do the dynamic linking as required (and we must omit the things - * we did to get the dynamic linker up and running in the first place. - * After we have done this, we just have a few housekeeping chores and we - * can transfer control to the user's application. - */ - -#include <stdarg.h> -#include "sysdep.h" /* before elf.h to get ELF_USES_RELOCA right */ -#include <elf.h> -#include "linuxelf.h" -#include "hash.h" -#include "syscall.h" -#include "string.h" -#include "../config.h" - -#define ALLOW_ZERO_PLTGOT - -/* Some arches may need to override this in boot1_arch.h */ -#define ELFMAGIC ELFMAG - -/* This is a poor man's malloc, used prior to resolving our internal poor man's malloc */ -#define DL_MALLOC(SIZE) ((void *) (malloc_buffer += SIZE, malloc_buffer - SIZE)) ; REALIGN(); -/* - * Make sure that the malloc buffer is aligned on 4 byte boundary. For 64 bit - * platforms we may need to increase this to 8, but this is good enough for - * now. This is typically called after DL_MALLOC. - */ -#define REALIGN() malloc_buffer = (char *) (((unsigned long) malloc_buffer + 3) & ~(3)) - -static char *_dl_malloc_addr, *_dl_mmap_zero; -char *_dl_library_path = 0; /* Where we look for libraries */ -char *_dl_preload = 0; /* Things to be loaded before the libs. */ -#include "ld.so.h" /* Pull in the name of ld.so */ -const char *_dl_progname=_dl_static_progname; -static char *_dl_not_lazy = 0; -#ifdef DL_TRACE -static char *_dl_trace_loaded_objects = 0; -#endif -static int (*_dl_elf_main) (int, char **, char **); -static int (*_dl_elf_init) (void); -void *(*_dl_malloc_function) (int size) = NULL; -struct r_debug *_dl_debug_addr = NULL; -unsigned long *_dl_brkp; -unsigned long *_dl_envp; -char *_dl_getenv(char *symbol, char **envp); -void _dl_unsetenv(char *symbol, char **envp); -int _dl_fixup(struct elf_resolve *tpnt); -void _dl_debug_state(void); -char *_dl_get_last_path_component(char *path); - -#include "boot1_arch.h" - - -/* When we enter this piece of code, the program stack looks like this: - argc argument counter (integer) - argv[0] program name (pointer) - argv[1...N] program args (pointers) - argv[argc-1] end of args (integer) - NULL - env[0...N] environment variables (pointers) - NULL - auxv_t[0...N] Auxiliary Vector Table elements (mixed types) -*/ - -#ifdef DL_DEBUG -/* Debugging is especially tricky on PowerPC, since string literals - * require relocations. Thus, you can't use _dl_dprintf() for - * anything until the bootstrap relocations are finished. */ -static inline void hexprint(unsigned long x) -{ - int i; - char c; - for(i=0;i<8;i++){ - c=((x>>28)+'0'); - if(c>'9')c+='a'-'9'-1; - _dl_write(1,&c,1); - x<<=4; - } - c='\n'; - _dl_write(1,&c,1); -} -#endif - -DL_BOOT(unsigned long args) -{ - unsigned int argc; - char **argv, **envp; - unsigned long load_addr; - unsigned long *got; - unsigned long *aux_dat; - int goof = 0; - elfhdr *header; - struct elf_resolve *tpnt; - struct dyn_elf *rpnt; - struct elf_resolve *app_tpnt; - unsigned long brk_addr; - Elf32_auxv_t auxv_t[AT_EGID + 1]; - unsigned char *malloc_buffer, *mmap_zero; - int (*_dl_atexit) (void *); - unsigned long *lpnt; - Elf32_Dyn *dpnt; - unsigned long *hash_addr; - struct r_debug *debug_addr; - unsigned long *chains; - int indx; - int _dl_secure; - int status; - - - /* WARNING! -- we cannot make _any_ funtion calls until we have - * taken care of fixing up our own relocations. Making static - * lnline calls is ok, but _no_ function calls. Not yet - * anyways. */ - - /* First obtain the information on the stack that tells us more about - what binary is loaded, where it is loaded, etc, etc */ - GET_ARGV(aux_dat,args); -#if defined(__arm__) - aux_dat+=1; -#endif - argc = *(aux_dat - 1); - argv = (char **) aux_dat; - aux_dat += argc; /* Skip over the argv pointers */ - aux_dat++; /* Skip over NULL at end of argv */ - envp = (char **) aux_dat; - while (*aux_dat) - aux_dat++; /* Skip over the envp pointers */ - aux_dat++; /* Skip over NULL at end of envp */ - - /* Place -1 here as a checkpoint. We later check if it was changed - * when we read in the auxv_t */ - auxv_t[AT_UID].a_type = -1; - - /* The junk on the stack immediately following the environment is - * the Auxiliary Vector Table. Read out the elements of the auxv_t, - * sort and store them in auxv_t for later use. */ - while (*aux_dat) - { - Elf32_auxv_t *auxv_entry = (Elf32_auxv_t*) aux_dat; - - if (auxv_entry->a_type <= AT_EGID) { - _dl_memcpy(&(auxv_t[auxv_entry->a_type]), - auxv_entry, sizeof(Elf32_auxv_t)); - } - aux_dat += 2; - } - - /* locate the ELF header. We need this done as soon as possible - * (esp since SEND_STDERR() needs this on some platforms... */ - load_addr = auxv_t[AT_BASE].a_un.a_val; - header = (elfhdr *) auxv_t[AT_BASE].a_un.a_ptr; - - /* Check the ELF header to make sure everything looks ok. */ - if (! header || header->e_ident[EI_CLASS] != ELFCLASS32 || - header->e_ident[EI_VERSION] != EV_CURRENT -#ifndef __powerpc__ - || _dl_strncmp((void *)header, ELFMAGIC, SELFMAG) != 0 -#endif - ) - { - SEND_STDERR("Invalid ELF header\n"); - _dl_exit(0); - } -#ifdef DL_DEBUG - SEND_STDERR("ELF header ="); - SEND_ADDRESS_STDERR(load_addr, 1); -#endif - - - /* Locate the global offset table. Since this code must be PIC - * we can take advantage of the magic offset register, if we - * happen to know what that is for this architecture. If not, - * we can always read stuff out of the ELF file to find it... */ -#if defined(__i386__) - __asm__("\tmovl %%ebx,%0\n\t" : "=a" (got)); -#elif defined(__m68k__) - __asm__ ("movel %%a5,%0" : "=g" (got)) -#elif defined(__sparc__) - __asm__("\tmov %%l7,%0\n\t" : "=r" (got)) -#elif defined(__arm__) - __asm__("\tmov %0, r10\n\t" : "=r"(got)); -#elif defined(__powerpc__) - __asm__("\tbl _GLOBAL_OFFSET_TABLE_-4@local\n\t" : "=l"(got)); -#else - /* Do things the slow way in C */ - { - unsigned long tx_reloc; - Elf32_Dyn *dynamic=NULL; - Elf32_Shdr *shdr; - Elf32_Phdr *pt_load; - -#ifdef DL_DEBUG - SEND_STDERR("Finding the got using C code to read the ELF file\n"); -#endif - /* Find where the dynamic linking information section is hiding */ - shdr = (Elf32_Shdr *)(header->e_shoff + (char *)header); - for (indx = header->e_shnum; --indx>=0; ++shdr) { - if (shdr->sh_type == SHT_DYNAMIC) { - goto found_dynamic; - } - } - SEND_STDERR("missing dynamic linking information section \n"); - _dl_exit(0); - -found_dynamic: - dynamic = (Elf32_Dyn*)(shdr->sh_offset + (char *)header); - - /* Find where PT_LOAD is hiding */ - pt_load = (Elf32_Phdr *)(header->e_phoff + (char *)header); - for (indx = header->e_phnum; --indx>=0; ++pt_load) { - if (pt_load->p_type == PT_LOAD) { - goto found_pt_load; - } - } - SEND_STDERR("missing loadable program segment\n"); - _dl_exit(0); - -found_pt_load: - /* Now (finally) find where DT_PLTGOT is hiding */ - tx_reloc = pt_load->p_vaddr - pt_load->p_offset; - for (; DT_NULL!=dynamic->d_tag; ++dynamic) { - if (dynamic->d_tag == DT_PLTGOT) { - goto found_got; - } - } - SEND_STDERR("missing global offset table\n"); - _dl_exit(0); - -found_got: - got = (unsigned long *)(dynamic->d_un.d_val - tx_reloc + (char *)header ); - } -#endif - - /* Now, finally, fix up the location of the dynamic stuff */ - dpnt = (Elf32_Dyn *) (*got + load_addr); -#ifdef DL_DEBUG - SEND_STDERR("First Dynamic section entry="); - SEND_ADDRESS_STDERR(dpnt, 1); -#endif - - - /* Call mmap to get a page of writable memory that can be used - * for _dl_malloc throughout the shared lib loader. */ - mmap_zero = malloc_buffer = _dl_mmap((void *) 0, 4096, - PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); - if (_dl_mmap_check_error(mmap_zero)) { - SEND_STDERR("dl_boot: mmap of a spare page failed!\n"); - _dl_exit(13); - } - - tpnt = DL_MALLOC(sizeof(struct elf_resolve)); - _dl_memset(tpnt, 0, sizeof(*tpnt)); - app_tpnt = DL_MALLOC(sizeof(struct elf_resolve)); - _dl_memset(app_tpnt, 0, sizeof(*app_tpnt)); - - /* - * This is used by gdb to locate the chain of shared libraries that are currently loaded. - */ - debug_addr = DL_MALLOC(sizeof(struct r_debug)); - _dl_memset(debug_addr, 0, sizeof(*debug_addr)); - - /* OK, that was easy. Next scan the DYNAMIC section of the image. - We are only doing ourself right now - we will have to do the rest later */ - - while (dpnt->d_tag) { - if(dpnt->d_tag<24) { - tpnt->dynamic_info[dpnt->d_tag] = dpnt->d_un.d_val; - if (dpnt->d_tag == DT_TEXTREL || SVR4_BUGCOMPAT) { - tpnt->dynamic_info[DT_TEXTREL] = 1; - } - } - dpnt++; - } - - { - elf_phdr *ppnt; - int i; - - ppnt = (elf_phdr *) auxv_t[AT_PHDR].a_un.a_ptr; - for (i = 0; i < auxv_t[AT_PHNUM].a_un.a_val; i++, ppnt++) - if (ppnt->p_type == PT_DYNAMIC) { - dpnt = (Elf32_Dyn *) ppnt->p_vaddr; - while (dpnt->d_tag) { - if (dpnt->d_tag > DT_JMPREL) { - dpnt++; - continue; - } - app_tpnt->dynamic_info[dpnt->d_tag] = dpnt->d_un.d_val; - if (dpnt->d_tag == DT_DEBUG) - dpnt->d_un.d_val = (unsigned long) debug_addr; - if (dpnt->d_tag == DT_TEXTREL || SVR4_BUGCOMPAT) - app_tpnt->dynamic_info[DT_TEXTREL] = 1; - dpnt++; - } - } - } - - /* Get some more of the information that we will need to dynamicly link - this module to itself */ - - hash_addr = (unsigned long *) (tpnt->dynamic_info[DT_HASH] + load_addr); - tpnt->nbucket = *hash_addr++; - tpnt->nchain = *hash_addr++; - tpnt->elf_buckets = hash_addr; - hash_addr += tpnt->nbucket; - chains = hash_addr; - - /* Ugly, ugly. We need to call mprotect to change the protection of - the text pages so that we can do the dynamic linking. We can set the - protection back again once we are done */ - - { - elf_phdr *ppnt; - int i; - - /* First cover the shared library/dynamic linker. */ - if (tpnt->dynamic_info[DT_TEXTREL]) { - header = (elfhdr *) auxv_t[AT_BASE].a_un.a_ptr; - ppnt = (elf_phdr *) (auxv_t[AT_BASE].a_un.a_ptr + header->e_phoff); - for (i = 0; i < header->e_phnum; i++, ppnt++) { - if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W)) - _dl_mprotect((void *) (load_addr + (ppnt->p_vaddr & 0xfffff000)), - (ppnt->p_vaddr & 0xfff) + (unsigned long) ppnt->p_filesz, - PROT_READ | PROT_WRITE | PROT_EXEC); - } - } - - /* Now cover the application program. */ - if (app_tpnt->dynamic_info[DT_TEXTREL]) { - ppnt = (elf_phdr *) auxv_t[AT_PHDR].a_un.a_ptr; - for (i = 0; i < auxv_t[AT_PHNUM].a_un.a_val; i++, ppnt++) { - if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W)) - _dl_mprotect((void *) (ppnt->p_vaddr & 0xfffff000), - (ppnt->p_vaddr & 0xfff) + - (unsigned long) ppnt->p_filesz, - PROT_READ | PROT_WRITE | PROT_EXEC); - } - } - } - - /* OK, now do the relocations. We do not do a lazy binding here, so - that once we are done, we have considerably more flexibility. */ - - goof = 0; - for (indx = 0; indx < 2; indx++) { - int i; - ELF_RELOC *rpnt; - unsigned long *reloc_addr; - unsigned long symbol_addr; - int symtab_index; - unsigned long rel_addr, rel_size; - - -#ifdef ELF_USES_RELOCA - rel_addr = - (indx ? tpnt->dynamic_info[DT_JMPREL] : tpnt-> - dynamic_info[DT_RELA]); - rel_size = - (indx ? tpnt->dynamic_info[DT_PLTRELSZ] : tpnt-> - dynamic_info[DT_RELASZ]); -#else - rel_addr = - (indx ? tpnt->dynamic_info[DT_JMPREL] : tpnt-> - dynamic_info[DT_REL]); - rel_size = - (indx ? tpnt->dynamic_info[DT_PLTRELSZ] : tpnt-> - dynamic_info[DT_RELSZ]); -#endif - - - if (!rel_addr) - continue; - - /* Now parse the relocation information */ - rpnt = (ELF_RELOC *) (rel_addr + load_addr); - for (i = 0; i < rel_size; i += sizeof(ELF_RELOC), rpnt++) { - reloc_addr = (unsigned long *) (load_addr + (unsigned long) rpnt->r_offset); - symtab_index = ELF32_R_SYM(rpnt->r_info); - symbol_addr = 0; - if (symtab_index) { - char *strtab; - Elf32_Sym *symtab; - - symtab = (Elf32_Sym *) (tpnt->dynamic_info[DT_SYMTAB] + load_addr); - strtab = (char *) (tpnt->dynamic_info[DT_STRTAB] + load_addr); - - /* We only do a partial dynamic linking right now. The user - is not supposed to redefine any symbols that start with - a '_', so we can do this with confidence. */ - - if (!_dl_symbol(strtab + symtab[symtab_index].st_name)) - continue; - - symbol_addr = load_addr + symtab[symtab_index].st_value; - - if (!symbol_addr) { - /* - * This will segfault - you cannot call a function until - * we have finished the relocations. - */ - SEND_STDERR("ELF dynamic loader - unable to " - "self-bootstrap - symbol "); - SEND_STDERR(strtab + symtab[symtab_index].st_name); - SEND_STDERR(" undefined.\n"); - goof++; - } - } - /* - * Use this machine-specific macro to perform the actual relocation. - */ - PERFORM_BOOTSTRAP_RELOC(rpnt, reloc_addr, symbol_addr, load_addr); - } - } - - if (goof) { - _dl_exit(14); - } - - /* OK, at this point we have a crude malloc capability. Start to build - the tables of the modules that are required for this beast to run. - We start with the basic executable, and then go from there. Eventually - we will run across ourself, and we will need to properly deal with that - as well. */ - _dl_malloc_addr = malloc_buffer; - _dl_mmap_zero = mmap_zero; - - /* Now we have done the mandatory linking of some things. We are now - free to start using global variables, since these things have all been - fixed up by now. Still no function calls outside of this library , - since the dynamic resolver is not yet ready. */ - lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT] + load_addr); - INIT_GOT(lpnt, tpnt); - - /* OK, this was a big step, now we need to scan all of the user images - and load them properly. */ - - tpnt->next = 0; - tpnt->libname = 0; - tpnt->libtype = program_interpreter; - - { - elfhdr *epnt; - elf_phdr *ppnt; - int i; - - epnt = (elfhdr *) auxv_t[AT_BASE].a_un.a_ptr; - tpnt->n_phent = epnt->e_phnum; - tpnt->ppnt = ppnt = (elf_phdr *) (load_addr + epnt->e_phoff); - for (i = 0; i < epnt->e_phnum; i++, ppnt++) { - if (ppnt->p_type == PT_DYNAMIC) { - tpnt->dynamic_addr = ppnt->p_vaddr + load_addr; - tpnt->dynamic_size = ppnt->p_filesz; - } - } - } - - tpnt->chains = chains; - tpnt->loadaddr = (char *) load_addr; - - brk_addr = 0; - rpnt = NULL; - - /* At this point we are now free to examine the user application, - and figure out which libraries are supposed to be called. Until - we have this list, we will not be completely ready for dynamic linking */ - - { - elf_phdr *ppnt; - int i; - - ppnt = (elf_phdr *) auxv_t[AT_PHDR].a_un.a_ptr; - for (i = 0; i < auxv_t[AT_PHNUM].a_un.a_val; i++, ppnt++) { - if (ppnt->p_type == PT_LOAD) { - if (ppnt->p_vaddr + ppnt->p_memsz > brk_addr) - brk_addr = ppnt->p_vaddr + ppnt->p_memsz; - } - if (ppnt->p_type == PT_DYNAMIC) { -#ifndef ALLOW_ZERO_PLTGOT - /* make sure it's really there. */ - if (app_tpnt->dynamic_info[DT_PLTGOT] == 0) - continue; -#endif - /* OK, we have what we need - slip this one into the list. */ - app_tpnt = _dl_add_elf_hash_table("", 0, - app_tpnt->dynamic_info, ppnt->p_vaddr, ppnt->p_filesz); - _dl_loaded_modules->libtype = elf_executable; - _dl_loaded_modules->ppnt = (elf_phdr *) auxv_t[AT_PHDR].a_un.a_ptr; - _dl_loaded_modules->n_phent = auxv_t[AT_PHNUM].a_un.a_val; - _dl_symbol_tables = rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf)); - _dl_memset(rpnt, 0, sizeof(*rpnt)); - rpnt->dyn = _dl_loaded_modules; - app_tpnt->usage_count++; - app_tpnt->symbol_scope = _dl_symbol_tables; - lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]); -#ifdef ALLOW_ZERO_PLTGOT - if (lpnt) -#endif - INIT_GOT(lpnt, _dl_loaded_modules); - } - if (ppnt->p_type == PT_INTERP) { /* OK, fill this in - we did not - have this before */ - tpnt->libname = _dl_strdup((char *) ppnt->p_offset + - (auxv_t[AT_PHDR].a_un.a_val & 0xfffff000)); - } - } - } - - if (argv[0]) { - _dl_progname = argv[0]; - } - - /* Now we need to figure out what kind of options are selected. - Note that for SUID programs we ignore the settings in LD_LIBRARY_PATH */ - { - _dl_not_lazy = _dl_getenv("LD_BIND_NOW", envp); - - if ((auxv_t[AT_UID].a_un.a_val == -1 && _dl_suid_ok()) || - (auxv_t[AT_UID].a_un.a_val != -1 && - auxv_t[AT_UID].a_un.a_val == auxv_t[AT_EUID].a_un.a_val - && auxv_t[AT_GID].a_un.a_val== auxv_t[AT_EGID].a_un.a_val)) { - _dl_secure = 0; - _dl_preload = _dl_getenv("LD_PRELOAD", envp); - _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp); - } else { - _dl_secure = 1; - _dl_preload = _dl_getenv("LD_PRELOAD", envp); - _dl_unsetenv("LD_AOUT_PRELOAD", envp); - _dl_unsetenv("LD_LIBRARY_PATH", envp); - _dl_unsetenv("LD_AOUT_LIBRARY_PATH", envp); - _dl_library_path = NULL; - } - } - -#ifdef DL_TRACE - _dl_trace_loaded_objects = _dl_getenv("LD_TRACE_LOADED_OBJECTS", envp); -#endif - /* OK, we now have the application in the list, and we have some - basic stuff in place. Now search through the list for other shared - libraries that should be loaded, and insert them on the list in the - correct order. */ - -#ifdef USE_CACHE - _dl_map_cache(); -#endif - - { - struct elf_resolve *tcurr; - struct elf_resolve *tpnt1; - char *lpnt; - - if (_dl_preload) - { - char c, *str, *str2; - - str = _dl_preload; - while (*str == ':' || *str == ' ' || *str == '\t') - str++; - while (*str) - { - str2 = str; - while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t') - str2++; - c = *str2; - *str2 = '\0'; - if (!_dl_secure || _dl_strchr(str, '/') == NULL) - { - tpnt1 = _dl_load_shared_library(_dl_secure, NULL, str); - if (!tpnt1) { -#ifdef DL_TRACE - if (_dl_trace_loaded_objects) - _dl_dprintf(1, "\t%s => not found\n", str); - else { -#endif - _dl_dprintf(2, "%s: can't load " - "library '%s'\n", _dl_progname, str); - _dl_exit(15); -#ifdef DL_TRACE - } -#endif - } else { -#ifdef DL_TRACE - if (_dl_trace_loaded_objects - && !tpnt1->usage_count) { - /* this is a real hack to make ldd not print - * the library itself when run on a library. */ - if (_dl_strcmp(_dl_progname, str) != 0) - _dl_dprintf(1, "\t%s => %s (0x%x)\n", str, tpnt1->libname, - (unsigned) tpnt1->loadaddr); - } -#endif - rpnt->next = (struct dyn_elf *) - _dl_malloc(sizeof(struct dyn_elf)); - _dl_memset(rpnt->next, 0, sizeof(*(rpnt->next))); - rpnt = rpnt->next; - tpnt1->usage_count++; - tpnt1->symbol_scope = _dl_symbol_tables; - tpnt1->libtype = elf_lib; - rpnt->dyn = tpnt1; - } - } - *str2 = c; - str = str2; - while (*str == ':' || *str == ' ' || *str == '\t') - str++; - } - } - - { - int fd; - struct stat st; - char *preload; - - if (!_dl_stat(LDSO_PRELOAD, &st) && st.st_size > 0) { - if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY)) < 0) { - _dl_dprintf(2, "%s: can't open file '%s'\n", - _dl_progname, LDSO_PRELOAD); - } else { - preload = (caddr_t) _dl_mmap(0, st.st_size + 1, - PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); - _dl_close(fd); - if (preload == (caddr_t) - 1) { - _dl_dprintf(2, "%s: can't map file '%s'\n", - _dl_progname, LDSO_PRELOAD); - } else { - char c, *cp, *cp2; - - /* convert all separators and comments to spaces */ - for (cp = preload; *cp; /*nada */ ) { - if (*cp == ':' || *cp == '\t' || *cp == '\n') { - *cp++ = ' '; - } else if (*cp == '#') { - do - *cp++ = ' '; - while (*cp != '\n' && *cp != '\0'); - } else { - cp++; - } - } - - /* find start of first library */ - for (cp = preload; *cp && *cp == ' '; cp++) - /*nada */ ; - - while (*cp) { - /* find end of library */ - for (cp2 = cp; *cp && *cp != ' '; cp++) - /*nada */ ; - c = *cp; - *cp = '\0'; - - tpnt1 = _dl_load_shared_library(0, NULL, cp2); - if (!tpnt1) { -#ifdef DL_TRACE - if (_dl_trace_loaded_objects) - _dl_dprintf(1, "\t%s => not found\n", cp2); - else { -#endif - _dl_dprintf(2, "%s: can't load library '%s'\n", - _dl_progname, cp2); - _dl_exit(15); -#ifdef DL_TRACE - } -#endif - } else { -#ifdef DL_TRACE - if (_dl_trace_loaded_objects - && !tpnt1->usage_count) { - _dl_dprintf(1, "\t%s => %s (0x%x)\n", cp2, - tpnt1->libname, (unsigned) tpnt1->loadaddr); - } -#endif - rpnt->next = (struct dyn_elf *) - _dl_malloc(sizeof(struct dyn_elf)); - _dl_memset(rpnt->next, 0, - sizeof(*(rpnt->next))); - rpnt = rpnt->next; - tpnt1->usage_count++; - tpnt1->symbol_scope = _dl_symbol_tables; - tpnt1->libtype = elf_lib; - rpnt->dyn = tpnt1; - } - - /* find start of next library */ - *cp = c; - for ( /*nada */ ; *cp && *cp == ' '; cp++) - /*nada */ ; - } - - _dl_munmap(preload, st.st_size + 1); - } - } - } - } - - for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) { - for (dpnt = (Elf32_Dyn *) tcurr->dynamic_addr; dpnt->d_tag; - dpnt++) { - if (dpnt->d_tag == DT_NEEDED) { - lpnt = tcurr->loadaddr + tcurr->dynamic_info[DT_STRTAB] + - dpnt->d_un.d_val; - if (tpnt && _dl_strcmp(lpnt, - _dl_get_last_path_component(tpnt->libname)) == 0) { - struct elf_resolve *ttmp; - -#ifdef DL_TRACE - if (_dl_trace_loaded_objects && !tpnt->usage_count) { - _dl_dprintf(1, "\t%s => %s (0x%x)\n", - lpnt, tpnt->libname, (unsigned) tpnt->loadaddr); - } -#endif - ttmp = _dl_loaded_modules; - while (ttmp->next) - ttmp = ttmp->next; - ttmp->next = tpnt; - tpnt->prev = ttmp; - tpnt->next = NULL; - rpnt->next = (struct dyn_elf *) - _dl_malloc(sizeof(struct dyn_elf)); - _dl_memset(rpnt->next, 0, sizeof(*(rpnt->next))); - rpnt = rpnt->next; - rpnt->dyn = tpnt; - tpnt->usage_count++; - tpnt->symbol_scope = _dl_symbol_tables; - tpnt = NULL; - continue; - } - if (!(tpnt1 = _dl_load_shared_library(0, tcurr, lpnt))) { -#ifdef DL_TRACE - if (_dl_trace_loaded_objects) - _dl_dprintf(1, "\t%s => not found\n", lpnt); - else { -#endif - _dl_dprintf(2, "%s: can't load library '%s'\n", - _dl_progname, lpnt); - _dl_exit(16); -#ifdef DL_TRACE - } -#endif - } else { -#ifdef DL_TRACE - if (_dl_trace_loaded_objects && !tpnt1->usage_count) - _dl_dprintf(1, "\t%s => %s (0x%x)\n", lpnt, tpnt1->libname, - (unsigned) tpnt1->loadaddr); -#endif - rpnt->next = (struct dyn_elf *) - _dl_malloc(sizeof(struct dyn_elf)); - _dl_memset(rpnt->next, 0, sizeof(*(rpnt->next))); - rpnt = rpnt->next; - tpnt1->usage_count++; - tpnt1->symbol_scope = _dl_symbol_tables; - tpnt1->libtype = elf_lib; - rpnt->dyn = tpnt1; - } - } - } - } - } - -#ifdef USE_CACHE - _dl_unmap_cache(); -#endif - /* ldd uses uses this. I am not sure how you pick up the other flags */ -#ifdef DL_TRACE - if (_dl_trace_loaded_objects) { - char *_dl_warn = 0; - _dl_warn = _dl_getenv("LD_WARN", envp); - if (!_dl_warn) - _dl_exit(0); - } -#endif - - /* - * If the program interpreter is not in the module chain, add it. This will - * be required for dlopen to be able to access the internal functions in the - * dynamic linker. - */ - if (tpnt) { - struct elf_resolve *tcurr; - - tcurr = _dl_loaded_modules; - if (tcurr) - while (tcurr->next) - tcurr = tcurr->next; - tpnt->next = NULL; - tpnt->usage_count++; - - if (tcurr) { - tcurr->next = tpnt; - tpnt->prev = tcurr; - } else { - _dl_loaded_modules = tpnt; - tpnt->prev = NULL; - } - if (rpnt) { - rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf)); - _dl_memset(rpnt->next, 0, sizeof(*(rpnt->next))); - rpnt = rpnt->next; - } else { - rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf)); - _dl_memset(rpnt, 0, sizeof(*(rpnt->next))); - } - rpnt->dyn = tpnt; - tpnt = NULL; - } - - /* - * OK, now all of the kids are tucked into bed in their proper addresses. - * Now we go through and look for REL and RELA records that indicate fixups - * to the GOT tables. We need to do this in reverse order so that COPY - * directives work correctly */ - goof = _dl_loaded_modules ? _dl_fixup(_dl_loaded_modules) : 0; - - - /* Some flavors of SVr4 do not generate the R_*_COPY directive, - and we have to manually search for entries that require fixups. - Solaris gets this one right, from what I understand. */ - - if (_dl_symbol_tables) - goof += _dl_copy_fixups(_dl_symbol_tables); -#ifdef DL_TRACE - if (goof || _dl_trace_loaded_objects) - _dl_exit(0); -#endif - - /* OK, at this point things are pretty much ready to run. Now we - need to touch up a few items that are required, and then - we can let the user application have at it. Note that - the dynamic linker itself is not guaranteed to be fully - dynamicly linked if we are using ld.so.1, so we have to look - up each symbol individually. */ - - - _dl_brkp = (unsigned long *) _dl_find_hash("___brk_addr", NULL, 1, NULL, 0); - if (_dl_brkp) - *_dl_brkp = brk_addr; - _dl_envp = - (unsigned long *) _dl_find_hash("__environ", NULL, 1, NULL, 0); - - if (_dl_envp) - *_dl_envp = (unsigned long) envp; - { - int i; - elf_phdr *ppnt; - - /* We had to set the protections of all pages to R/W for dynamic linking. - Set text pages back to R/O */ - for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) - for (ppnt = tpnt->ppnt, i = 0; i < tpnt->n_phent; i++, ppnt++) - if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W) && - tpnt->dynamic_info[DT_TEXTREL]) - _dl_mprotect((void *) (tpnt->loadaddr + (ppnt->p_vaddr & 0xfffff000)), - (ppnt->p_vaddr & 0xfff) + (unsigned long) ppnt->p_filesz, - LXFLAGS(ppnt->p_flags)); - - } - - _dl_atexit = (int (*)(void *)) _dl_find_hash("atexit", NULL, 1, NULL, 0); - - /* - * OK, fix one more thing - set up the debug_addr structure to point - * to our chain. Later we may need to fill in more fields, but this - * should be enough for now. - */ - debug_addr->r_map = (struct link_map *) _dl_loaded_modules; - debug_addr->r_version = 1; - debug_addr->r_ldbase = load_addr; - debug_addr->r_brk = (unsigned long) &_dl_debug_state; - _dl_debug_addr = debug_addr; - debug_addr->r_state = RT_CONSISTENT; - /* This is written in this funny way to keep gcc from inlining the - function call. */ - ((void (*)(void)) debug_addr->r_brk) (); - - for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) { - /* Apparently crt1 for the application is responsible for handling this. - * We only need to run the init/fini for shared libraries - */ - if (tpnt->libtype == program_interpreter || - tpnt->libtype == elf_executable) - continue; - if (tpnt->init_flag & INIT_FUNCS_CALLED) - continue; - tpnt->init_flag |= INIT_FUNCS_CALLED; - - if (tpnt->dynamic_info[DT_INIT]) { - _dl_elf_init = (int (*)(void)) (tpnt->loadaddr + - tpnt->dynamic_info[DT_INIT]); - (*_dl_elf_init) (); - } - if (_dl_atexit && tpnt->dynamic_info[DT_FINI]) { - (*_dl_atexit) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]); - } -#undef DL_DEBUG -#ifdef DL_DEBUG - else { - _dl_dprintf(2, tpnt->libname); - _dl_dprintf(2, ": "); - if (!_dl_atexit) - _dl_dprintf(2, "The address is atexit () is 0x0."); - if (!tpnt->dynamic_info[DT_FINI]) - _dl_dprintf(2, "Invalid .fini section."); - _dl_dprintf(2, "\n"); - } -#endif -#undef DL_DEBUG - } - - /* OK we are done here. Turn out the lights, and lock up. */ - _dl_elf_main = (int (*)(int, char **, char **)) auxv_t[AT_ENTRY].a_un.a_fcn; - - - /* - * Transfer control to the application. - */ - status = 0; /* Used on x86, but not on other arches */ - START(); -} - -/* - * This stub function is used by some debuggers. The idea is that they - * can set an internal breakpoint on it, so that we are notified when the - * address mapping is changed in some way. - */ -void _dl_debug_state() -{ - return; -} - -int _dl_fixup(struct elf_resolve *tpnt) -{ - int goof = 0; - - if (tpnt->next) - goof += _dl_fixup(tpnt->next); - if (tpnt->dynamic_info[DT_REL]) { -#ifdef ELF_USES_RELOCA - _dl_dprintf(2, "%s: can't handle REL relocation records\n", - _dl_progname); - _dl_exit(17); -#else - if (tpnt->init_flag & RELOCS_DONE) - return goof; - tpnt->init_flag |= RELOCS_DONE; - goof += _dl_parse_relocation_information(tpnt, - tpnt->dynamic_info[DT_REL], tpnt->dynamic_info[DT_RELSZ], 0); -#endif - } - if (tpnt->dynamic_info[DT_RELA]) { -#ifdef ELF_USES_RELOCA - if (tpnt->init_flag & RELOCS_DONE) - return goof; - tpnt->init_flag |= RELOCS_DONE; - goof += _dl_parse_relocation_information(tpnt, - tpnt->dynamic_info[DT_RELA], tpnt->dynamic_info[DT_RELASZ], 0); -#else - _dl_dprintf(2, "%s: can't handle RELA relocation records\n", - _dl_progname); - _dl_exit(18); -#endif - } - if (tpnt->dynamic_info[DT_JMPREL]) { - if (tpnt->init_flag & JMP_RELOCS_DONE) - return goof; - tpnt->init_flag |= JMP_RELOCS_DONE; - if (!_dl_not_lazy || *_dl_not_lazy == 0) - _dl_parse_lazy_relocation_information(tpnt, - tpnt->dynamic_info[DT_JMPREL], tpnt->dynamic_info[DT_PLTRELSZ], 0); - else - goof += _dl_parse_relocation_information(tpnt, - tpnt->dynamic_info[DT_JMPREL], tpnt->dynamic_info[DT_PLTRELSZ], 0); - } - return goof; -} - -void *_dl_malloc(int size) -{ - void *retval; - -#ifdef DL_DEBUG - SEND_STDERR("malloc: request for "); - SEND_NUMBER_STDERR(size, 0); - SEND_STDERR(" bytes\n"); -#endif - - if (_dl_malloc_function) - return (*_dl_malloc_function) (size); - - if (_dl_malloc_addr - _dl_mmap_zero + size > 4096) { -#ifdef DL_DEBUG - SEND_STDERR("malloc: mmapping more memory\n"); -#endif - _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, size, - PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); - if (_dl_mmap_check_error(_dl_mmap_zero)) { - _dl_dprintf(2, "%s: mmap of a spare page failed!\n", _dl_progname); - _dl_exit(20); - } - } - retval = _dl_malloc_addr; - _dl_malloc_addr += size; - - /* - * Align memory to 4 byte boundary. Some platforms require this, others - * simply get better performance. - */ - _dl_malloc_addr = (char *) (((unsigned long) _dl_malloc_addr + 3) & ~(3)); - return retval; -} - -char *_dl_getenv(char *symbol, char **envp) -{ - char *pnt; - char *pnt1; - - while ((pnt = *envp++)) { - pnt1 = symbol; - while (*pnt && *pnt == *pnt1) - pnt1++, pnt++; - if (!*pnt || *pnt != '=' || *pnt1) - continue; - return pnt + 1; - } - return 0; -} - -void _dl_unsetenv(char *symbol, char **envp) -{ - char *pnt; - char *pnt1; - char **newenvp = envp; - - for (pnt = *envp; pnt; pnt = *++envp) { - pnt1 = symbol; - while (*pnt && *pnt == *pnt1) - pnt1++, pnt++; - if (!*pnt || *pnt != '=' || *pnt1) - *newenvp++ = *envp; - } - *newenvp++ = *envp; - return; -} - -char *_dl_strdup(const char *string) -{ - char *retval; - int len; - - len = _dl_strlen(string); - retval = _dl_malloc(len + 1); - _dl_strcpy(retval, string); - return retval; -} - -/* Minimum printf which handles only characters, %d's and %s's */ -void _dl_dprintf(int fd, const char *fmt, ...) -{ - int num; - va_list args; - char *start, *ptr, *string; - char buf[2048]; - - start = ptr = buf; - - if (!fmt) - return; - - if (_dl_strlen(fmt) >= (sizeof(buf)-1)) - _dl_write(fd, "(overflow)\n", 10); - - _dl_strcpy(buf, fmt); - va_start(args, fmt); - - while(start) - { - while(*ptr != '%' && *ptr) { - ptr++; - } - - if(*ptr == '%') - { - *ptr++ = '\0'; - _dl_write(fd, start, _dl_strlen(start)); - - switch(*ptr++) - { - case 's': - string = va_arg(args, char *); - if (!string) - _dl_write(fd, "(null)", 6); - else - _dl_write(fd, string, _dl_strlen(string)); - break; - - case 'i': - case 'd': - { - char tmp[13]; - num = va_arg(args, int); - string = _dl_simple_ltoa(tmp, num); - _dl_write(fd, string, _dl_strlen(string)); - break; - } - case 'x': - case 'X': - { - char tmp[13]; - num = va_arg(args, int); - string = _dl_simple_ltoahex(tmp, num); - _dl_write(fd, string, _dl_strlen(string)); - break; - } - default: - _dl_write(fd, "(null)", 6); - break; - } - - start = ptr; - } - else - { - _dl_write(fd, start, _dl_strlen(start)); - start = NULL; - } - } - return; -} - diff --git a/ldso/ldso/ldso.c b/ldso/ldso/ldso.c index e61276cce..0d9df3054 100644 --- a/ldso/ldso/ldso.c +++ b/ldso/ldso/ldso.c @@ -91,13 +91,11 @@ * can transfer control to the user's application. */ -#include <stdarg.h> -#include "sysdep.h" /* before elf.h to get ELF_USES_RELOCA right */ -#include <elf.h> #include "linuxelf.h" -#include "hash.h" -#include "syscall.h" -#include "string.h" +#include <stdarg.h> +#include "ld_hash.h" +#include "ld_syscall.h" +#include "ld_string.h" #include "../config.h" #define ALLOW_ZERO_PLTGOT @@ -117,7 +115,7 @@ static char *_dl_malloc_addr, *_dl_mmap_zero; char *_dl_library_path = 0; /* Where we look for libraries */ char *_dl_preload = 0; /* Things to be loaded before the libs. */ -#include "ld.so.h" /* Pull in the name of ld.so */ +#include "ld-uClibc.h" /* Pull in the name of ld.so */ const char *_dl_progname=_dl_static_progname; static char *_dl_not_lazy = 0; #ifdef DL_TRACE |