/* vi: set sw=4 ts=4: */ /* * This file contains the helper routines to load an ELF shared * library into memory and add the symbol table info to the chain. * * Copyright (C) 2000-2006 by Erik Andersen * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald, * David Engel, Hongjiu Lu and Mitch D'Souza * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. The name of the above contributors may not be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include "ldso.h" #ifdef __LDSO_CACHE_SUPPORT__ static caddr_t _dl_cache_addr = NULL; static size_t _dl_cache_size = 0; int _dl_map_cache(void) { int fd; struct stat st; header_t *header; libentry_t *libent; int i, strtabsize; if (_dl_cache_addr == (caddr_t) - 1) return -1; else if (_dl_cache_addr != NULL) return 0; if (_dl_stat(LDSO_CACHE, &st) || (fd = _dl_open(LDSO_CACHE, O_RDONLY, 0)) < 0) { _dl_cache_addr = (caddr_t) - 1; /* so we won't try again */ return -1; } _dl_cache_size = st.st_size; _dl_cache_addr = _dl_mmap(0, _dl_cache_size, PROT_READ, LDSO_CACHE_MMAP_FLAGS, fd, 0); _dl_close(fd); if (_dl_mmap_check_error(_dl_cache_addr)) { _dl_dprintf(2, "%s:%i: can't map '%s'\n", _dl_progname, __LINE__, LDSO_CACHE); return -1; } header = (header_t *) _dl_cache_addr; if (_dl_cache_size < sizeof(header_t) || _dl_memcmp(header->magic, LDSO_CACHE_MAGIC, LDSO_CACHE_MAGIC_LEN) || _dl_memcmp(header->version, LDSO_CACHE_VER, LDSO_CACHE_VER_LEN) || _dl_cache_size < (sizeof(header_t) + header->nlibs * sizeof(libentry_t)) || _dl_cache_addr[_dl_cache_size - 1] != '\0') { _dl_dprintf(2, "%s: cache '%s' is corrupt\n", _dl_progname, LDSO_CACHE); goto fail; } strtabsize = _dl_cache_size - sizeof(header_t) - header->nlibs * sizeof(libentry_t); libent = (libentry_t *) & header[1]; for (i = 0; i < header->nlibs; i++) { if (libent[i].sooffset >= strtabsize || libent[i].liboffset >= strtabsize) { _dl_dprintf(2, "%s: cache '%s' is corrupt\n", _dl_progname, LDSO_CACHE); goto fail; } } return 0; fail: _dl_munmap(_dl_cache_addr, _dl_cache_size); _dl_cache_addr = (caddr_t) - 1; return -1; } int _dl_unmap_cache(void) { if (_dl_cache_addr == NULL || _dl_cache_addr == (caddr_t) - 1) return -1; #if 1 _dl_munmap(_dl_cache_addr, _dl_cache_size); _dl_cache_addr = NULL; #endif return 0; } #endif void _dl_protect_relro (struct elf_resolve *l) { ElfW(Addr) base = (ElfW(Addr)) DL_RELOC_ADDR(l->loadaddr, l->relro_addr); ElfW(Addr) start = (base & ~(_dl_pagesize - 1)); ElfW(Addr) end = ((base + l->relro_size) & ~(_dl_pagesize - 1)); _dl_if_debug_dprint("RELRO protecting %s: start:%x, end:%x\n", l->libname, start, end); if (start != end && _dl_mprotect ((void *) start, end - start, PROT_READ) < 0) { _dl_dprintf(2, "%s: cannot apply additional memory protection after relocation", l->libname); _dl_exit(0); } } /* This function's behavior must exactly match that * in uClibc/ldso/util/ldd.c */ static struct elf_resolve * search_for_named_library(const char *name, int secure, const char *path_list, struct dyn_elf **rpnt) { char *path, *path_n, *mylibname; struct elf_resolve *tpnt; int done; if (path_list==NULL) return NULL; /* We need a writable copy of this string, but we don't * need this allocated permanently since we don't want * to leak memory, so use alloca to put path on the stack */ done = _dl_strlen(path_list); path = alloca(done + 1); /* another bit of local storage */ mylibname = alloca(2050); /* gcc inlines alloca using a single instruction adjusting * the stack pointer and no stack overflow check and thus * no NULL error return. No point leaving in dead code... */ #if 0 if (!path || !mylibname) { _dl_dprintf(2, "Out of memory!\n"); _dl_exit(0); } #endif _dl_memcpy(path, path_list, done+1); /* Unlike ldd.c, don't bother to eliminate double //s */ /* Replace colons with zeros in path_list */ /* : at the beginning or end of path maps to CWD */ /* :: anywhere maps CWD */ /* "" maps to CWD */ done = 0; path_n = path; do { if (*path == 0) { *path = ':'; done = 1; } if (*path == ':') { *path = 0; if (*path_n) _dl_strcpy(mylibname, path_n); else _dl_strcpy(mylibname, "."); /* Assume current dir if empty path */ _dl_strcat(mylibname, "/"); _dl_strcat(mylibname, name); if ((tpnt = _dl_load_elf_shared_library(secure, rpnt, mylibname)) != NULL) return tpnt; path_n = path+1; } path++; } while (!done); return NULL; } /* Used to return error codes back to dlopen et. al. */ unsigned long _dl_error_number; unsigned long _dl_internal_error_number; struct elf_resolve *_dl_load_shared_library(int secure, struct dyn_elf **rpnt, struct elf_resolve *tpnt, char *full_libname, int __attribute__((unused)) trace_loaded_objects) { char *pnt; struct elf_resolve *tpnt1; char *libname; _dl_internal_error_number = 0; libname = full_libname; /* quick hack to ensure mylibname buffer doesn't overflow. don't allow full_libname or any directory to be longer than 1024. */ if (_dl_strlen(full_libname) > 1024) goto goof; /* Skip over any initial initial './' and '/' stuff to * get the short form libname with no path garbage */ pnt = _dl_strrchr(libname, '/'); if (pnt) { libname = pnt + 1; } _dl_if_debug_dprint("\tfind library='%s'; searching\n", libname); /* If the filename has any '/', try it straight and leave it at that. For IBCS2 compatibility under linux, we substitute the string /usr/i486-sysv4/lib for /usr/lib in library names. */ if (libname != full_libname) { _dl_if_debug_dprint("\ttrying file='%s'\n", full_libname); tpnt1 = _dl_load_elf_shared_library(secure, rpnt, full_libname); if (tpnt1) { return tpnt1; } } /* * The ABI specifies that RPATH is searched before LD_LIBRARY_PATH or * the default path of /usr/lib. Check in rpath directories. */ #ifdef __LDSO_RUNPATH__ pnt = (tpnt ? (char *) tpnt->dynamic_info[DT_RPATH] : NULL); if (pnt) { pnt += (unsigned long) tpnt->dynamic_info[DT_STRTAB]; _dl_if_debug_dprint("\tsearching RPATH='%s'\n", pnt); if ((tpnt1 = search_for_named_library(libname, secure, pnt, rpnt)) != NULL) return tpnt1; } #endif /* Check in LD_{ELF_}LIBRARY_PATH, if specified and allowed */ if (_dl_library_path) { _dl_if_debug_dprint("\tsearching LD_LIBRARY_PATH='%s'\n", _dl_library_path); if ((tpnt1 = search_for_named_library(libname, secure, _dl_library_path, rpnt)) != NULL) { return tpnt1; } } /* * The ABI specifies that RUNPATH is searched after LD_LIBRARY_PATH. */ #ifdef __LDSO_RUNPATH__ pnt = (tpnt ? (char *)tpnt->dynamic_info[DT_RUNPATH] : NULL); if (pnt) { pnt += (unsigned long) tpnt->dynamic_info[DT_STRTAB]; _dl_if_debug_dprint("\tsearching RUNPATH='%s'\n", pnt); if ((tpnt1 = search_for_named_library(libname, secure, pnt, rpnt)) != NULL) return tpnt1; } #endif /* * Where should the cache be searched? There is no such concept in the * ABI, so we have some flexibility here. For now, search it before * the hard coded paths that follow (i.e before /lib and /usr/lib). */ #ifdef __LDSO_CACHE_SUPPORT__ if (_dl_cache_addr != NULL && _dl_cache_addr != (caddr_t) - 1) { int i; header_t *header = (header_t *) _dl_cache_addr; libentry_t *libent = (libentry_t *) & header[1]; char *strs = (char *) &libent[header->nlibs]; _dl_if_debug_dprint("\tsearching cache='%s'\n", LDSO_CACHE); for (i = 0; i < header->nlibs; i++) { if ((libent[i].flags == LIB_ELF || libent[i].flags == LIB_ELF_LIBC0 || libent[i].flags == LIB_ELF_LIBC5) && _dl_strcmp(libname, strs + libent[i].sooffset) == 0 && (tpnt1 = _dl_load_elf_shared_library(secure, rpnt, strs + libent[i].liboffset))) return tpnt1; } } #endif /* Look for libraries wherever the shared library loader * was installed */ _dl_if_debug_dprint("\tsearching ldso dir='%s'\n", _dl_ldsopath); if ((tpnt1 = search_for_named_library(libname, secure, _dl_ldsopath, rpnt)) != NULL) { return tpnt1; } /* Lastly, search the standard list of paths for the library. This list must exactly match the list in uClibc/ldso/util/ldd.c */ _dl_if_debug_dprint("\tsearching full lib path list\n"); if ((tpnt1 = search_for_named_library(libname, secure, UCLIBC_RUNTIME_PREFIX "lib:" UCLIBC_RUNTIME_PREFIX "usr/lib" #ifndef __LDSO_CACHE_SUPPORT__ ":" UCLIBC_RUNTIME_PREFIX "usr/X11R6/lib" #endif , rpnt) ) != NULL) { return tpnt1; } goof: /* Well, we shot our wad on that one. All we can do now is punt */ if (_dl_internal_error_number) _dl_error_number = _dl_internal_error_number; else _dl_error_number = LD_ERROR_NOFILE; _dl_if_debug_dprint("Bummer: could not find '%s'!\n", libname); return NULL; } /* * Read one ELF library into memory, mmap it into the correct locations and * add the symbol info to the symbol chain. Perform any relocations that * are required. */ struct elf_resolve *_dl_load_elf_shared_library(int secure, struct dyn_elf **rpnt, char *libname) { ElfW(Ehdr) *epnt; unsigned long dynamic_addr = 0; ElfW(Dyn) *dpnt; struct elf_resolve *tpnt; ElfW(Phdr) *ppnt; char *status, *header; unsigned long dynamic_info[DYNAMIC_SIZE]; unsigned long *lpnt; unsigned long libaddr; unsigned long minvma = 0xffffffff, maxvma = 0; int i, flags, piclib, infile; ElfW(Addr) relro_addr = 0; size_t relro_size = 0; struct stat st; DL_LOADADDR_TYPE lib_loadaddr; DL_INIT_LOADADDR_EXTRA_DECLS libaddr = 0; infile = _dl_open(libname, O_RDONLY, 0); if (infile < 0) { _dl_internal_error_number = LD_ERROR_NOFILE; return NULL; } if (_dl_fstat(infile, &st) < 0) { _dl_internal_error_number = LD_ERROR_NOFILE; _dl_close(infile); return NULL; } /* If we are in secure mode (i.e. a setu/gid binary using LD_PRELOAD), we don't load the library if it isn't setuid. */ if (secure) if (!(st.st_mode & S_ISUID)) { _dl_close(infile); return NULL; } /* Check if file is already loaded */ for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) { if (tpnt->st_dev == st.st_dev && tpnt->st_ino == st.st_ino) { /* Already loaded */ tpnt->usage_count++; _dl_close(infile); return tpnt; } } header = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (_dl_mmap_check_error(header)) { _dl_dprintf(2, "%s:%i: can't map '%s'\n", _dl_progname, __LINE__, libname); _dl_internal_error_number = LD_ERROR_MMAP_FAILED; _dl_close(infile); return NULL; } _dl_read(infile, header, _dl_pagesize); epnt = (ElfW(Ehdr) *) (intptr_t) header; if (epnt->e_ident[0] != 0x7f || epnt->e_ident[1] != 'E' || epnt->e_ident[2] != 'L' || epnt->e_ident[3] != 'F') { _dl_dprintf(2, "%s: '%s' is not an ELF file\n", _dl_progname, libname); _dl_internal_error_number = LD_ERROR_NOTELF; _dl_close(infile); _dl_munmap(header, _dl_pagesize); return NULL; } if ((epnt->e_type != ET_DYN) || (epnt->e_machine != MAGIC1 #ifdef MAGIC2 && epnt->e_machine != MAGIC2 #endif )) { _dl_internal_error_number = (epnt->e_type != ET_DYN ? LD_ERROR_NOTDYN : LD_ERROR_NOTMAGIC); _dl_dprintf(2, "%s: '%s' is not an ELF executable for " ELF_TARGET "\n", _dl_progname, libname); _dl_close(infile); _dl_munmap(header, _dl_pagesize); return NULL; } ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff]; piclib = 1; for (i = 0; i < epnt->e_phnum; i++) { if (ppnt->p_type == PT_DYNAMIC) { if (dynamic_addr) _dl_dprintf(2, "%s: '%s' has more than one dynamic section\n", _dl_progname, libname); dynamic_addr = ppnt->p_vaddr; } if (ppnt->p_type == PT_LOAD) { /* See if this is a PIC library. */ if (i == 0 && ppnt->p_vaddr > 0x1000000) { piclib = 0; minvma = ppnt->p_vaddr; } if (piclib && ppnt->p_vaddr < minvma) { minvma = ppnt->p_vaddr; } if (((unsigned long) ppnt->p_vaddr + ppnt->p_memsz) > maxvma) { maxvma = ppnt->p_vaddr + ppnt->p_memsz; } } ppnt++; } DL_CHECK_LIB_TYPE (epnt, piclib, _dl_progname, libname); maxvma = (maxvma + ADDR_ALIGN) & ~ADDR_ALIGN; minvma = minvma & ~0xffffU; flags = MAP_PRIVATE /*| MAP_DENYWRITE */ ; if (!piclib) flags |= MAP_FIXED; if (piclib == 0 || piclib == 1) { status = (char *) _dl_mmap((char *) (piclib ? 0 : minvma), maxvma - minvma, PROT_NONE, flags | MAP_ANONYMOUS, -1, 0); if (_dl_mmap_check_error(status)) { _dl_dprintf(2, "%s:%i: can't map '%s'\n", _dl_progname, __LINE__, libname); _dl_internal_error_number = LD_ERROR_MMAP_FAILED; _dl_close(infile); _dl_munmap(header, _dl_pagesize); return NULL; } libaddr = (unsigned long) status; flags |= MAP_FIXED; } /* Get the memory to store the library */ ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff]; DL_INIT_LOADADDR(lib_loadaddr, libaddr, ppnt, epnt->e_phnum); for (i = 0; i < epnt->e_phnum; i++) { if (DL_IS_SPECIAL_SEGMENT (epnt, ppnt)) { char *addr; addr = DL_MAP_SEGMENT (epnt, ppnt, infile, flags); if (addr == NULL) goto cant_map; DL_INIT_LOADADDR_HDR (lib_loadaddr, addr, ppnt); ppnt++; continue; } if (ppnt->p_type == PT_GNU_RELRO) { relro_addr = ppnt->p_vaddr; relro_size = ppnt->p_memsz; } if (ppnt->p_type == PT_LOAD) { char *tryaddr; ssize_t size; /* See if this is a PIC library. */ if (i == 0 && ppnt->p_vaddr > 0x1000000) { piclib = 0; /* flags |= MAP_FIXED; */ } if (ppnt->p_flags & PF_W) { unsigned long map_size; char *cpnt; char *piclib2map = 0; if (piclib == 2 && /* We might be able to avoid this call if memsz doesn't require an additional page, but this would require mmap to always return page-aligned addresses and a whole number of pages allocated. Unfortunately on uClinux may return misaligned addresses and may allocate partial pages, so we may end up doing unnecessary mmap calls. This is what we could do if we knew mmap would always return aligned pages: ((ppnt->p_vaddr + ppnt->p_filesz + ADDR_ALIGN) & PAGE_ALIGN) < ppnt->p_vaddr + ppnt->p_memsz) Instead, we have to do this: */ ppnt->p_filesz < ppnt->p_memsz) { piclib2map = (char *) _dl_mmap(0, (ppnt->p_vaddr & ADDR_ALIGN) + ppnt->p_memsz, LXFLAGS(ppnt->p_flags), flags | MAP_ANONYMOUS, -1, 0); if (_dl_mmap_check_error(piclib2map)) goto cant_map; DL_INIT_LOADADDR_HDR (lib_loadaddr, piclib2map + (ppnt->p_vaddr & ADDR_ALIGN), ppnt); } tryaddr = piclib == 2 ? piclib2map : ((char*) (piclib ? libaddr : 0) + (ppnt->p_vaddr & PAGE_ALIGN)); size = (ppnt->p_vaddr & ADDR_ALIGN) + ppnt->p_filesz; /* For !MMU, mmap to fixed address will fail. So instead of desperately call mmap and fail, we set status to MAP_FAILED to save a call to mmap (). */ #ifndef __ARCH_USE_MMU__ if (piclib2map == 0) #endif status = (char *) _dl_mmap (tryaddr, size, LXFLAGS(ppnt->p_flags), flags | (piclib2map ? MAP_FIXED : 0), infile, ppnt->p_offset & OFFS_ALIGN); #ifndef __ARCH_USE_MMU__ else status = MAP_FAILED; #endif #ifdef _DL_PREAD if (_dl_mmap_check_error(status) && piclib2map && (_DL_PREAD (infile, tryaddr, size, ppnt->p_offset & OFFS_ALIGN) == size)) status = tryaddr; #endif if (_dl_mmap_check_error(status) || (tryaddr && tryaddr != status)) { cant_map: _dl_dprintf(2, "%s:%i: can't map '%s'\n", _dl_progname, __LINE__, libname); _dl_internal_error_number = LD_ERROR_MMAP_FAILED; DL_LOADADDR_UNMAP (lib_loadaddr, maxvma - minvma); _dl_close(infile); _dl_munmap(header, _dl_pagesize); return NULL; } if (! piclib2map) { DL_INIT_LOADADDR_HDR (lib_loadaddr, status + (ppnt->p_vaddr & ADDR_ALIGN), ppnt); } /* Now we want to allocate and zero-out any data from the end of the region we mapped in from the file (filesz) to the end of the loadable segment (memsz). We may need additional pages for memsz, that we map in below, and we can count on the kernel to zero them out, but we have to zero out stuff in the last page that we mapped in from the file. However, we can't assume to have actually obtained full pages from the kernel, since we didn't ask for them, and uClibc may not give us full pages for small allocations. So only zero out up to memsz or the end of the page, whichever comes first. */ /* CPNT is the beginning of the memsz portion not backed by filesz. */ cpnt = (char *) (status + size); /* MAP_SIZE is the address of the beginning of the next page. */ map_size = (ppnt->p_vaddr + ppnt->p_filesz + ADDR_ALIGN) & PAGE_ALIGN; #ifndef MIN # define MIN(a,b) ((a) < (b) ? (a) : (b)) #endif _dl_memset (cpnt, 0, MIN (map_size - (ppnt->p_vaddr + ppnt->p_filesz), ppnt->p_memsz - ppnt->p_filesz)); if (map_size < ppnt->p_vaddr + ppnt->p_memsz && !piclib2map) { tryaddr = map_size + (char*)(piclib ? libaddr : 0); status = (char *) _dl_mmap(tryaddr, ppnt->p_vaddr + ppnt->p_memsz - map_size, LXFLAGS(ppnt->p_flags), flags | MAP_ANONYMOUS | MAP_FIXED, -1, 0); if (_dl_mmap_check_error(status) || tryaddr != status) goto cant_map; } } else { tryaddr = (piclib == 2 ? 0 : (char *) (ppnt->p_vaddr & PAGE_ALIGN) + (piclib ? libaddr : 0)); size = (ppnt->p_vaddr & ADDR_ALIGN) + ppnt->p_filesz; status = (char *) _dl_mmap (tryaddr, size, LXFLAGS(ppnt->p_flags), flags | (piclib == 2 ? MAP_EXECUTABLE | MAP_DENYWRITE : 0), infile, ppnt->p_offset & OFFS_ALIGN); if (_dl_mmap_check_error(status) || (tryaddr && tryaddr != status)) goto cant_map; DL_INIT_LOADADDR_HDR (lib_loadaddr, status + (ppnt->p_vaddr & ADDR_ALIGN), ppnt); } /* if (libaddr == 0 && piclib) { libaddr = (unsigned long) status; flags |= MAP_FIXED; } */ } ppnt++; } _dl_close(infile); /* For a non-PIC library, the addresses are all absolute */ if (piclib) { dynamic_addr = (unsigned long) DL_RELOC_ADDR(lib_loadaddr, dynamic_addr); } /* * OK, the ELF library is now loaded into VM in the correct locations * The next step is to go through and do the dynamic linking (if needed). */ /* Start by scanning the dynamic section to get all of the pointers */ if (!dynamic_addr) { _dl_internal_error_number = LD_ERROR_NODYNAMIC; _dl_dprintf(2, "%s: '%s' is missing a dynamic section\n", _dl_progname, libname); _dl_munmap(header, _dl_pagesize); return NULL; } dpnt = (ElfW(Dyn) *) dynamic_addr; _dl_memset(dynamic_info, 0, sizeof(dynamic_info)); _dl_parse_dynamic_info(dpnt, dynamic_info, NULL, lib_loadaddr); /* If the TEXTREL is set, this means that we need to make the pages writable before we perform relocations. Do this now. They get set back again later. */ if (dynamic_info[DT_TEXTREL]) { #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__ ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff]; for (i = 0; i < epnt->e_phnum; i++, ppnt++) { if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W)) _dl_mprotect((void *) ((piclib ? libaddr : 0) + (ppnt->p_vaddr & PAGE_ALIGN)), (ppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) ppnt->p_filesz, PROT_READ | PROT_WRITE | PROT_EXEC); } #else _dl_dprintf(_dl_debug_file, "Can't modify %s's text section. Use GCC option -fPIC for shared objects, please.\n",libname); _dl_exit(1); #endif } tpnt = _dl_add_elf_hash_table(libname, lib_loadaddr, dynamic_info, dynamic_addr, 0); tpnt->relro_addr = relro_addr; tpnt->relro_size = relro_size; tpnt->st_dev = st.st_dev; tpnt->st_ino = st.st_ino; tpnt->ppnt = (ElfW(Phdr) *) DL_RELOC_ADDR(tpnt->loadaddr, epnt->e_phoff); tpnt->n_phent = epnt->e_phnum; /* * Add this object into the symbol chain */ if (*rpnt) { (*rpnt)->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf)); _dl_memset((*rpnt)->next, 0, sizeof(struct dyn_elf)); (*rpnt)->next->prev = (*rpnt); *rpnt = (*rpnt)->next; } #ifndef SHARED /* When statically linked, the first time we dlopen a DSO * the *rpnt is NULL, so we need to allocate memory for it, * and initialize the _dl_symbol_table. */ else { *rpnt = _dl_symbol_tables = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf)); _dl_memset(*rpnt, 0, sizeof(struct dyn_elf)); } #endif (*rpnt)->dyn = tpnt; tpnt->symbol_scope = _dl_symbol_tables; tpnt->usage_count++; tpnt->libtype = elf_lib; /* * OK, the next thing we need to do is to insert the dynamic linker into * the proper entry in the GOT so that the PLT symbols can be properly * resolved. */ lpnt = (unsigned long *) dynamic_info[DT_PLTGOT]; if (lpnt) { lpnt = (unsigned long *) (dynamic_info[DT_PLTGOT]); INIT_GOT(lpnt, tpnt); } _dl_if_debug_dprint("\n\tfile='%s'; generating link map\n", libname); _dl_if_debug_dprint("\t\tdynamic: %x base: %x\n", dynamic_addr, DL_LOADADDR_BASE(lib_loadaddr)); _dl_if_debug_dprint("\t\t entry: %x phdr: %x phnum: %x\n\n", DL_RELOC_ADDR(lib_loadaddr, epnt->e_entry), tpnt->ppnt, tpnt->n_phent); _dl_munmap(header, _dl_pagesize); return tpnt; } /* now_flag must be RTLD_NOW or zero */ int _dl_fixup(struct dyn_elf *rpnt, int now_flag) { int goof = 0; struct elf_resolve *tpnt; ElfW(Word) reloc_size, relative_count; ElfW(Addr) reloc_addr; if (rpnt->next) goof = _dl_fixup(rpnt->next, now_flag); if (goof) return goof; tpnt = rpnt->dyn; if (!(tpnt->init_flag & RELOCS_DONE)) _dl_if_debug_dprint("relocation processing: %s\n", tpnt->libname); if (unlikely(tpnt->dynamic_info[UNSUPPORTED_RELOC_TYPE])) { _dl_if_debug_dprint("%s: can't handle %s relocation records\n", _dl_progname, UNSUPPORTED_RELOC_STR); goof++; return goof; } reloc_size = tpnt->dynamic_info[DT_RELOC_TABLE_SIZE]; /* On some machines, notably SPARC & PPC, DT_REL* includes DT_JMPREL in its range. Note that according to the ELF spec, this is completely legal! */ #ifdef ELF_MACHINE_PLTREL_OVERLAP reloc_size -= tpnt->dynamic_info [DT_PLTRELSZ]; #endif if (tpnt->dynamic_info[DT_RELOC_TABLE_ADDR] && !(tpnt->init_flag & RELOCS_DONE)) { reloc_addr = tpnt->dynamic_info[DT_RELOC_TABLE_ADDR]; relative_count = tpnt->dynamic_info[DT_RELCONT_IDX]; if (relative_count) { /* Optimize the XX_RELATIVE relocations if possible */ reloc_size -= relative_count * sizeof(ELF_RELOC); elf_machine_relative(tpnt->loadaddr, reloc_addr, relative_count); reloc_addr += relative_count * sizeof(ELF_RELOC); } goof += _dl_parse_relocation_information(rpnt, reloc_addr, reloc_size); tpnt->init_flag |= RELOCS_DONE; } if (tpnt->dynamic_info[DT_BIND_NOW]) now_flag = RTLD_NOW; if (tpnt->dynamic_info[DT_JMPREL] && (!(tpnt->init_flag & JMP_RELOCS_DONE) || (now_flag && !(tpnt->rtld_flags & now_flag)))) { tpnt->rtld_flags |= now_flag; if (!(tpnt->rtld_flags & RTLD_NOW)) { _dl_parse_lazy_relocation_information(rpnt, tpnt->dynamic_info[DT_JMPREL], tpnt->dynamic_info [DT_PLTRELSZ]); } else { goof += _dl_parse_relocation_information(rpnt, tpnt->dynamic_info[DT_JMPREL], tpnt->dynamic_info[DT_PLTRELSZ]); } tpnt->init_flag |= JMP_RELOCS_DONE; } return goof; } /* Minimal printf which handles only %s, %d, and %x */ void _dl_dprintf(int fd, const char *fmt, ...) { #if __WORDSIZE > 32 long int num; #else int num; #endif va_list args; char *start, *ptr, *string; static char *buf; if (!fmt) return; buf = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (_dl_mmap_check_error(buf)) { _dl_write(fd, "mmap of a spare page failed!\n", 29); _dl_exit(20); } start = ptr = buf; if (_dl_strlen(fmt) >= (_dl_pagesize - 1)) { _dl_write(fd, "overflow\n", 11); _dl_exit(20); } _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[22]; #if __WORDSIZE > 32 num = va_arg(args, long int); #else num = va_arg(args, int); #endif string = _dl_simple_ltoa(tmp, num); _dl_write(fd, string, _dl_strlen(string)); break; } case 'x': case 'X': { char tmp[22]; #if __WORDSIZE > 32 num = va_arg(args, long int); #else num = va_arg(args, int); #endif 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; } } _dl_munmap(buf, _dl_pagesize); 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; } void _dl_parse_dynamic_info(ElfW(Dyn) *dpnt, unsigned long dynamic_info[], void *debug_addr, DL_LOADADDR_TYPE load_off) { __dl_parse_dynamic_info(dpnt, dynamic_info, debug_addr, load_off); } /* we want this in ldso.so and libdl.a but nowhere else */ #ifdef __USE_GNU #if defined IS_IN_rtld || (defined IS_IN_libdl && ! defined SHARED) extern __typeof(dl_iterate_phdr) __dl_iterate_phdr; int __dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info, size_t size, void *data), void *data) { struct elf_resolve *l; struct dl_phdr_info info; int ret = 0; for (l = _dl_loaded_modules; l != NULL; l = l->next) { info.dlpi_addr = l->loadaddr; info.dlpi_name = l->libname; info.dlpi_phdr = l->ppnt; info.dlpi_phnum = l->n_phent; ret = callback (&info, sizeof (struct dl_phdr_info), data); if (ret) break; } return ret; } strong_alias(__dl_iterate_phdr, dl_iterate_phdr) #endif #endif