auto import from //depot/cupcake/@135843
diff --git a/linker/linker.c b/linker/linker.c
new file mode 100644
index 0000000..91435de
--- /dev/null
+++ b/linker/linker.c
@@ -0,0 +1,1761 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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
+ * COPYRIGHT OWNER OR 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 <linux/auxvec.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <dlfcn.h>
+#include <sys/stat.h>
+
+//#include <pthread.h>
+
+#include <sys/mman.h>
+
+#include <sys/atomics.h>
+
+/* special private C library header - see Android.mk */
+#include <bionic_tls.h>
+
+#include "linker.h"
+#include "linker_debug.h"
+
+#include "ba.h"
+
+#define SO_MAX 64
+
+/* >>> IMPORTANT NOTE - READ ME BEFORE MODIFYING <<<
+ *
+ * Do NOT use malloc() and friends or pthread_*() code here.
+ * Don't use printf() either; it's caused mysterious memory
+ * corruption in the past.
+ * The linker runs before we bring up libc and it's easiest
+ * to make sure it does not depend on any complex libc features
+ *
+ * open issues / todo:
+ *
+ * - should we do anything special for STB_WEAK symbols?
+ * - are we doing everything we should for ARM_COPY relocations?
+ * - cleaner error reporting
+ * - configuration for paths (LD_LIBRARY_PATH?)
+ * - after linking, set as much stuff as possible to READONLY
+ * and NOEXEC
+ * - linker hardcodes PAGE_SIZE and PAGE_MASK because the kernel
+ * headers provide versions that are negative...
+ * - allocate space for soinfo structs dynamically instead of
+ * having a hard limit (64)
+ *
+ * features to add someday:
+ *
+ * - dlopen() and friends
+ *
+*/
+
+
+static int link_image(soinfo *si, unsigned wr_offset);
+
+static int socount = 0;
+static soinfo sopool[SO_MAX];
+static soinfo *freelist = NULL;
+static soinfo *solist = &libdl_info;
+static soinfo *sonext = &libdl_info;
+
+int debug_verbosity;
+static int pid;
+
+#if STATS
+struct _link_stats linker_stats;
+#endif
+
+#if COUNT_PAGES
+unsigned bitmask[4096];
+#endif
+
+#ifndef PT_ARM_EXIDX
+#define PT_ARM_EXIDX 0x70000001 /* .ARM.exidx segment */
+#endif
+
+/*
+ * This function is an empty stub where GDB locates a breakpoint to get notified
+ * about linker activity.
+ */
+extern void __attribute__((noinline)) rtld_db_dlactivity(void);
+
+extern void sched_yield(void);
+
+static struct r_debug _r_debug = {1, NULL, &rtld_db_dlactivity,
+ RT_CONSISTENT, 0};
+static struct link_map *r_debug_tail = 0;
+
+//static pthread_mutex_t _r_debug_lock = PTHREAD_MUTEX_INITIALIZER;
+
+static volatile int loader_lock = 0;
+
+static void insert_soinfo_into_debug_map(soinfo * info)
+{
+ struct link_map * map;
+
+ /* Copy the necessary fields into the debug structure.
+ */
+ map = &(info->linkmap);
+ map->l_addr = info->base;
+ map->l_name = (char*) info->name;
+
+ /* Stick the new library at the end of the list.
+ * gdb tends to care more about libc than it does
+ * about leaf libraries, and ordering it this way
+ * reduces the back-and-forth over the wire.
+ */
+ if (r_debug_tail) {
+ r_debug_tail->l_next = map;
+ map->l_prev = r_debug_tail;
+ map->l_next = 0;
+ } else {
+ _r_debug.r_map = map;
+ map->l_prev = 0;
+ map->l_next = 0;
+ }
+ r_debug_tail = map;
+}
+
+void notify_gdb_of_load(soinfo * info)
+{
+ if (info->flags & FLAG_EXE) {
+ // GDB already knows about the main executable
+ return;
+ }
+
+ /* yes, this is a little gross, but it does avoid
+ ** pulling in pthread_*() and at the moment we don't
+ ** dlopen() anything anyway
+ */
+ while(__atomic_swap(1, &loader_lock) != 0) {
+ sched_yield();
+ usleep(5000);
+ }
+
+ _r_debug.r_state = RT_ADD;
+ rtld_db_dlactivity();
+
+ insert_soinfo_into_debug_map(info);
+
+ _r_debug.r_state = RT_CONSISTENT;
+ rtld_db_dlactivity();
+
+ __atomic_swap(0, &loader_lock);
+}
+
+void notify_gdb_of_libraries()
+{
+ _r_debug.r_state = RT_ADD;
+ rtld_db_dlactivity();
+ _r_debug.r_state = RT_CONSISTENT;
+ rtld_db_dlactivity();
+}
+
+static soinfo *alloc_info(const char *name)
+{
+ soinfo *si;
+
+ if(strlen(name) >= SOINFO_NAME_LEN) {
+ ERROR("%5d library name %s too long\n", pid, name);
+ return 0;
+ }
+
+ /* The freelist is populated when we call free_info(), which in turn is
+ done only by dlclose(), which is not likely to be used.
+ */
+ if (!freelist) {
+ if(socount == SO_MAX) {
+ ERROR("%5d too many libraries when loading %s\n", pid, name);
+ return NULL;
+ }
+ freelist = sopool + socount++;
+ freelist->next = NULL;
+ }
+
+ si = freelist;
+ freelist = freelist->next;
+
+ /* Make sure we get a clean block of soinfo */
+ memset(si, 0, sizeof(soinfo));
+ strcpy((char*) si->name, name);
+ sonext->next = si;
+ si->ba_index = -1; /* by default, prelinked */
+ si->next = NULL;
+ si->refcount = 0;
+ sonext = si;
+
+ TRACE("%5d name %s: allocated soinfo @ %p\n", pid, name, si);
+ return si;
+}
+
+static void free_info(soinfo *si)
+{
+ soinfo *prev = NULL, *trav;
+
+ TRACE("%5d name %s: freeing soinfo @ %p\n", pid, si->name, si);
+
+ for(trav = solist; trav != NULL; trav = trav->next){
+ if (trav == si)
+ break;
+ prev = trav;
+ }
+ if (trav == NULL) {
+ /* si was not ni solist */
+ ERROR("%5d name %s is not in solist!\n", pid, si->name);
+ return;
+ }
+
+ /* prev will never be NULL, because the first entry in solist is
+ always the static libdl_info.
+ */
+ prev->next = si->next;
+ if (si == sonext) sonext = prev;
+ si->next = freelist;
+ freelist = si;
+}
+
+#ifndef LINKER_TEXT_BASE
+#error "linker's makefile must define LINKER_TEXT_BASE"
+#endif
+#ifndef LINKER_AREA_SIZE
+#error "linker's makefile must define LINKER_AREA_SIZE"
+#endif
+#define LINKER_BASE ((LINKER_TEXT_BASE) & 0xfff00000)
+#define LINKER_TOP (LINKER_BASE + (LINKER_AREA_SIZE))
+
+const char *addr_to_name(unsigned addr)
+{
+ soinfo *si;
+
+ for(si = solist; si != 0; si = si->next){
+ if((addr >= si->base) && (addr < (si->base + si->size))) {
+ return si->name;
+ }
+ }
+
+ if((addr >= LINKER_BASE) && (addr < LINKER_TOP)){
+ return "linker";
+ }
+
+ return "";
+}
+
+/* For a given PC, find the .so that it belongs to.
+ * Returns the base address of the .ARM.exidx section
+ * for that .so, and the number of 8-byte entries
+ * in that section (via *pcount).
+ *
+ * Intended to be called by libc's __gnu_Unwind_Find_exidx().
+ *
+ * This function is exposed via dlfcn.c and libdl.so.
+ */
+#ifdef ANDROID_ARM_LINKER
+_Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc, int *pcount)
+{
+ soinfo *si;
+ unsigned addr = (unsigned)pc;
+
+ if ((addr < LINKER_BASE) || (addr >= LINKER_TOP)) {
+ for (si = solist; si != 0; si = si->next){
+ if ((addr >= si->base) && (addr < (si->base + si->size))) {
+ *pcount = si->ARM_exidx_count;
+ return (_Unwind_Ptr)(si->base + (unsigned long)si->ARM_exidx);
+ }
+ }
+ }
+ *pcount = 0;
+ return NULL;
+}
+#elif defined(ANDROID_X86_LINKER)
+/* Here, we only have to provide a callback to iterate across all the
+ * loaded libraries. gcc_eh does the rest. */
+int
+dl_iterate_phdr(int (*cb)(struct dl_phdr_info *info, size_t size, void *data),
+ void *data)
+{
+ soinfo *si;
+ struct dl_phdr_info dl_info;
+ int rv = 0;
+
+ for (si = solist; si != NULL; si = si->next) {
+ dl_info.dlpi_addr = si->linkmap.l_addr;
+ dl_info.dlpi_name = si->linkmap.l_name;
+ dl_info.dlpi_phdr = si->phdr;
+ dl_info.dlpi_phnum = si->phnum;
+ rv = cb(&dl_info, sizeof (struct dl_phdr_info), data);
+ if (rv != 0)
+ break;
+ }
+ return rv;
+}
+#endif
+
+static Elf32_Sym *_elf_lookup(soinfo *si, unsigned hash, const char *name)
+{
+ Elf32_Sym *s;
+ Elf32_Sym *symtab = si->symtab;
+ const char *strtab = si->strtab;
+ unsigned n;
+
+ TRACE_TYPE(LOOKUP, "%5d SEARCH %s in %s@0x%08x %08x %d\n", pid,
+ name, si->name, si->base, hash, hash % si->nbucket);
+ n = hash % si->nbucket;
+
+ for(n = si->bucket[hash % si->nbucket]; n != 0; n = si->chain[n]){
+ s = symtab + n;
+ if(strcmp(strtab + s->st_name, name)) continue;
+
+ /* only concern ourselves with global symbols */
+ switch(ELF32_ST_BIND(s->st_info)){
+ case STB_GLOBAL:
+ /* no section == undefined */
+ if(s->st_shndx == 0) continue;
+
+ case STB_WEAK:
+ TRACE_TYPE(LOOKUP, "%5d FOUND %s in %s (%08x) %d\n", pid,
+ name, si->name, s->st_value, s->st_size);
+ return s;
+ }
+ }
+
+ return 0;
+}
+
+static unsigned elfhash(const char *_name)
+{
+ const unsigned char *name = (const unsigned char *) _name;
+ unsigned h = 0, g;
+
+ while(*name) {
+ h = (h << 4) + *name++;
+ g = h & 0xf0000000;
+ h ^= g;
+ h ^= g >> 24;
+ }
+ return h;
+}
+
+static Elf32_Sym *
+_do_lookup_in_so(soinfo *si, const char *name, unsigned *elf_hash)
+{
+ if (*elf_hash == 0)
+ *elf_hash = elfhash(name);
+ return _elf_lookup (si, *elf_hash, name);
+}
+
+/* This is used by dl_sym() */
+Elf32_Sym *lookup_in_library(soinfo *si, const char *name)
+{
+ unsigned unused = 0;
+ return _do_lookup_in_so(si, name, &unused);
+}
+
+static Elf32_Sym *
+_do_lookup(soinfo *user_si, const char *name, unsigned *base)
+{
+ unsigned elf_hash = 0;
+ Elf32_Sym *s = NULL;
+ soinfo *si;
+
+ /* Look for symbols in the local scope first (the object who is
+ * searching). This happens with C++ templates on i386 for some
+ * reason. */
+ if (user_si) {
+ s = _do_lookup_in_so(user_si, name, &elf_hash);
+ if (s != NULL)
+ *base = user_si->base;
+ }
+
+ for(si = solist; (s == NULL) && (si != NULL); si = si->next)
+ {
+ if((si->flags & FLAG_ERROR) || (si == user_si))
+ continue;
+ s = _do_lookup_in_so(si, name, &elf_hash);
+ if (s != NULL) {
+ *base = si->base;
+ break;
+ }
+ }
+
+ if (s != NULL) {
+ TRACE_TYPE(LOOKUP, "%5d %s s->st_value = 0x%08x, "
+ "si->base = 0x%08x\n", pid, name, s->st_value, si->base);
+ return s;
+ }
+
+ return 0;
+}
+
+/* This is used by dl_sym() */
+Elf32_Sym *lookup(const char *name, unsigned *base)
+{
+ return _do_lookup(NULL, name, base);
+}
+
+#if 0
+static void dump(soinfo *si)
+{
+ Elf32_Sym *s = si->symtab;
+ unsigned n;
+
+ for(n = 0; n < si->nchain; n++) {
+ TRACE("%5d %04d> %08x: %02x %04x %08x %08x %s\n", pid, n, s,
+ s->st_info, s->st_shndx, s->st_value, s->st_size,
+ si->strtab + s->st_name);
+ s++;
+ }
+}
+#endif
+
+static const char *sopaths[] = {
+ "/system/lib",
+ "/lib",
+ 0
+};
+
+static int _open_lib(const char *name)
+{
+ int fd;
+ struct stat filestat;
+
+ if ((stat(name, &filestat) >= 0) && S_ISREG(filestat.st_mode)) {
+ if ((fd = open(name, O_RDONLY)) >= 0)
+ return fd;
+ }
+
+ return -1;
+}
+
+/* TODO: Need to add support for initializing the so search path with
+ * LD_LIBRARY_PATH env variable for non-setuid programs. */
+static int open_library(const char *name)
+{
+ int fd;
+ char buf[512];
+ const char **path;
+
+ TRACE("[ %5d opening %s ]\n", pid, name);
+
+ if(name == 0) return -1;
+ if(strlen(name) > 256) return -1;
+
+ if ((name[0] == '/') && ((fd = _open_lib(name)) >= 0))
+ return fd;
+
+ for (path = sopaths; *path; path++) {
+ snprintf(buf, sizeof(buf), "%s/%s", *path, name);
+ if ((fd = _open_lib(buf)) >= 0)
+ return fd;
+ }
+
+ return -1;
+}
+
+/* temporary space for holding the first page of the shared lib
+ * which contains the elf header (with the pht). */
+static unsigned char __header[PAGE_SIZE];
+
+typedef struct {
+ long mmap_addr;
+ char tag[4]; /* 'P', 'R', 'E', ' ' */
+} prelink_info_t;
+
+/* Returns the requested base address if the library is prelinked,
+ * and 0 otherwise. */
+static unsigned long
+is_prelinked(int fd, const char *name)
+{
+ off_t sz;
+ prelink_info_t info;
+
+ sz = lseek(fd, -sizeof(prelink_info_t), SEEK_END);
+ if (sz < 0) {
+ ERROR("lseek() failed!\n");
+ return 0;
+ }
+
+ if (read(fd, &info, sizeof(info)) != sizeof(info)) {
+ WARN("Could not read prelink_info_t structure for `%s`\n", name);
+ return 0;
+ }
+
+ if (strncmp(info.tag, "PRE ", 4)) {
+ WARN("`%s` is not a prelinked library\n", name);
+ return 0;
+ }
+
+ return (unsigned long)info.mmap_addr;
+}
+
+/* verify_elf_object
+ * Verifies if the object @ base is a valid ELF object
+ *
+ * Args:
+ *
+ * Returns:
+ * 0 on success
+ * -1 if no valid ELF object is found @ base.
+ */
+static int
+verify_elf_object(void *base, const char *name)
+{
+ Elf32_Ehdr *hdr = (Elf32_Ehdr *) base;
+
+ if (hdr->e_ident[EI_MAG0] != ELFMAG0) return -1;
+ if (hdr->e_ident[EI_MAG1] != ELFMAG1) return -1;
+ if (hdr->e_ident[EI_MAG2] != ELFMAG2) return -1;
+ if (hdr->e_ident[EI_MAG3] != ELFMAG3) return -1;
+
+ /* TODO: Should we verify anything else in the header? */
+
+ return 0;
+}
+
+
+/* get_lib_extents
+ * Retrieves the base (*base) address where the ELF object should be
+ * mapped and its overall memory size (*total_sz).
+ *
+ * Args:
+ * fd: Opened file descriptor for the library
+ * name: The name of the library
+ * _hdr: Pointer to the header page of the library
+ * total_sz: Total size of the memory that should be allocated for
+ * this library
+ *
+ * Returns:
+ * -1 if there was an error while trying to get the lib extents.
+ * The possible reasons are:
+ * - Could not determine if the library was prelinked.
+ * - The library provided is not a valid ELF object
+ * 0 if the library did not request a specific base offset (normal
+ * for non-prelinked libs)
+ * > 0 if the library requests a specific address to be mapped to.
+ * This indicates a pre-linked library.
+ */
+static unsigned
+get_lib_extents(int fd, const char *name, void *__hdr, unsigned *total_sz)
+{
+ unsigned req_base;
+ unsigned min_vaddr = 0xffffffff;
+ unsigned max_vaddr = 0;
+ unsigned char *_hdr = (unsigned char *)__hdr;
+ Elf32_Ehdr *ehdr = (Elf32_Ehdr *)_hdr;
+ Elf32_Phdr *phdr;
+ int cnt;
+
+ TRACE("[ %5d Computing extents for '%s'. ]\n", pid, name);
+ if (verify_elf_object(_hdr, name) < 0) {
+ ERROR("%5d - %s is not a valid ELF object\n", pid, name);
+ return (unsigned)-1;
+ }
+
+ req_base = (unsigned) is_prelinked(fd, name);
+ if (req_base == (unsigned)-1)
+ return -1;
+ else if (req_base != 0) {
+ TRACE("[ %5d - Prelinked library '%s' requesting base @ 0x%08x ]\n",
+ pid, name, req_base);
+ } else {
+ TRACE("[ %5d - Non-prelinked library '%s' found. ]\n", pid, name);
+ }
+
+ phdr = (Elf32_Phdr *)(_hdr + ehdr->e_phoff);
+
+ /* find the min/max p_vaddrs from all the PT_LOAD segments so we can
+ * get the range. */
+ for (cnt = 0; cnt < ehdr->e_phnum; ++cnt, ++phdr) {
+ if (phdr->p_type == PT_LOAD) {
+ if ((phdr->p_vaddr + phdr->p_memsz) > max_vaddr)
+ max_vaddr = phdr->p_vaddr + phdr->p_memsz;
+ if (phdr->p_vaddr < min_vaddr)
+ min_vaddr = phdr->p_vaddr;
+ }
+ }
+
+ if ((min_vaddr == 0xffffffff) && (max_vaddr == 0)) {
+ ERROR("%5d - No loadable segments found in %s.\n", pid, name);
+ return (unsigned)-1;
+ }
+
+ /* truncate min_vaddr down to page boundary */
+ min_vaddr &= ~PAGE_MASK;
+
+ /* round max_vaddr up to the next page */
+ max_vaddr = (max_vaddr + PAGE_SIZE - 1) & ~PAGE_MASK;
+
+ *total_sz = (max_vaddr - min_vaddr);
+ return (unsigned)req_base;
+}
+
+/* alloc_mem_region
+ *
+ * This function reserves a chunk of memory to be used for mapping in
+ * the shared library. We reserve the entire memory region here, and
+ * then the rest of the linker will relocate the individual loadable
+ * segments into the correct locations within this memory range.
+ *
+ * Args:
+ * si->base: The requested base of the allocation. If 0, a sane one will be
+ * chosen in the range LIBBASE <= base < LIBLAST.
+ * si->size: The size of the allocation.
+ *
+ * Returns:
+ * -1 on failure, and 0 on success. On success, si->base will contain
+ * the virtual address at which the library will be mapped.
+ */
+
+static int reserve_mem_region(soinfo *si)
+{
+ void *base = mmap((void *)si->base, si->size, PROT_READ | PROT_EXEC,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ if (base == MAP_FAILED) {
+ ERROR("%5d can NOT map (%sprelinked) library '%s' at 0x%08x "
+ "as requested, will try general pool: %d (%s)\n",
+ pid, (si->base ? "" : "non-"), si->name, si->base,
+ errno, strerror(errno));
+ return -1;
+ } else if (base != (void *)si->base) {
+ ERROR("OOPS: %5d %sprelinked library '%s' mapped at 0x%08x, "
+ "not at 0x%08x\n", pid, (si->base ? "" : "non-"),
+ si->name, (unsigned)base, si->base);
+ munmap(base, si->size);
+ return -1;
+ }
+ return 0;
+}
+
+static int
+alloc_mem_region(soinfo *si)
+{
+ if (si->base) {
+ /* Attempt to mmap a prelinked library. */
+ si->ba_index = -1;
+ return reserve_mem_region(si);
+ }
+
+ /* This is not a prelinked library, so we attempt to allocate space
+ for it from the buddy allocator, which manages the area between
+ LIBBASE and LIBLAST.
+ */
+ si->ba_index = ba_allocate(si->size);
+ if(si->ba_index >= 0) {
+ si->base = ba_start_addr(si->ba_index);
+ PRINT("%5d mapping library '%s' at %08x (index %d) " \
+ "through buddy allocator.\n",
+ pid, si->name, si->base, si->ba_index);
+ if (reserve_mem_region(si) < 0) {
+ ba_free(si->ba_index);
+ si->ba_index = -1;
+ si->base = 0;
+ goto err;
+ }
+ return 0;
+ }
+
+err:
+ ERROR("OOPS: %5d cannot map library '%s'. no vspace available.\n",
+ pid, si->name);
+ return -1;
+}
+
+#define MAYBE_MAP_FLAG(x,from,to) (((x) & (from)) ? (to) : 0)
+#define PFLAGS_TO_PROT(x) (MAYBE_MAP_FLAG((x), PF_X, PROT_EXEC) | \
+ MAYBE_MAP_FLAG((x), PF_R, PROT_READ) | \
+ MAYBE_MAP_FLAG((x), PF_W, PROT_WRITE))
+/* load_segments
+ *
+ * This function loads all the loadable (PT_LOAD) segments into memory
+ * at their appropriate memory offsets off the base address.
+ *
+ * Args:
+ * fd: Open file descriptor to the library to load.
+ * header: Pointer to a header page that contains the ELF header.
+ * This is needed since we haven't mapped in the real file yet.
+ * si: ptr to soinfo struct describing the shared object.
+ *
+ * Returns:
+ * 0 on success, -1 on failure.
+ */
+static int
+load_segments(int fd, void *header, soinfo *si)
+{
+ Elf32_Ehdr *ehdr = (Elf32_Ehdr *)header;
+ Elf32_Phdr *phdr = (Elf32_Phdr *)((unsigned char *)header + ehdr->e_phoff);
+ unsigned char *base = (unsigned char *)si->base;
+ int cnt;
+ unsigned len;
+ unsigned char *tmp;
+ unsigned char *pbase;
+ unsigned char *extra_base;
+ unsigned extra_len;
+ unsigned total_sz = 0;
+
+ si->wrprotect_start = 0xffffffff;
+ si->wrprotect_end = 0;
+
+ TRACE("[ %5d - Begin loading segments for '%s' @ 0x%08x ]\n",
+ pid, si->name, (unsigned)si->base);
+ /* Now go through all the PT_LOAD segments and map them into memory
+ * at the appropriate locations. */
+ for (cnt = 0; cnt < ehdr->e_phnum; ++cnt, ++phdr) {
+ if (phdr->p_type == PT_LOAD) {
+ DEBUG_DUMP_PHDR(phdr, "PT_LOAD", pid);
+ /* we want to map in the segment on a page boundary */
+ tmp = base + (phdr->p_vaddr & (~PAGE_MASK));
+ /* add the # of bytes we masked off above to the total length. */
+ len = phdr->p_filesz + (phdr->p_vaddr & PAGE_MASK);
+
+ TRACE("[ %d - Trying to load segment from '%s' @ 0x%08x "
+ "(0x%08x). p_vaddr=0x%08x p_offset=0x%08x ]\n", pid, si->name,
+ (unsigned)tmp, len, phdr->p_vaddr, phdr->p_offset);
+ pbase = mmap(tmp, len, PFLAGS_TO_PROT(phdr->p_flags),
+ MAP_PRIVATE | MAP_FIXED, fd,
+ phdr->p_offset & (~PAGE_MASK));
+ if (pbase == MAP_FAILED) {
+ ERROR("%d failed to map segment from '%s' @ 0x%08x (0x%08x). "
+ "p_vaddr=0x%08x p_offset=0x%08x\n", pid, si->name,
+ (unsigned)tmp, len, phdr->p_vaddr, phdr->p_offset);
+ goto fail;
+ }
+
+ /* If 'len' didn't end on page boundary, and it's a writable
+ * segment, zero-fill the rest. */
+ if ((len & PAGE_MASK) && (phdr->p_flags & PF_W))
+ memset((void *)(pbase + len), 0, PAGE_SIZE - (len & PAGE_MASK));
+
+ /* Check to see if we need to extend the map for this segment to
+ * cover the diff between filesz and memsz (i.e. for bss).
+ *
+ * base _+---------------------+ page boundary
+ * . .
+ * | |
+ * . .
+ * pbase _+---------------------+ page boundary
+ * | |
+ * . .
+ * base + p_vaddr _| |
+ * . \ \ .
+ * . | filesz | .
+ * pbase + len _| / | |
+ * <0 pad> . . .
+ * extra_base _+------------|--------+ page boundary
+ * / . . .
+ * | . . .
+ * | +------------|--------+ page boundary
+ * extra_len-> | | | |
+ * | . | memsz .
+ * | . | .
+ * \ _| / |
+ * . .
+ * | |
+ * _+---------------------+ page boundary
+ */
+ tmp = (unsigned char *)(((unsigned)pbase + len + PAGE_SIZE - 1) &
+ (~PAGE_MASK));
+ if (tmp < (base + phdr->p_vaddr + phdr->p_memsz)) {
+ extra_len = base + phdr->p_vaddr + phdr->p_memsz - tmp;
+ TRACE("[ %5d - Need to extend segment from '%s' @ 0x%08x "
+ "(0x%08x) ]\n", pid, si->name, (unsigned)tmp, extra_len);
+ /* map in the extra page(s) as anonymous into the range.
+ * This is probably not necessary as we already mapped in
+ * the entire region previously, but we just want to be
+ * sure. This will also set the right flags on the region
+ * (though we can probably accomplish the same thing with
+ * mprotect).
+ */
+ extra_base = mmap((void *)tmp, extra_len,
+ PFLAGS_TO_PROT(phdr->p_flags),
+ MAP_PRIVATE | MAP_FIXED | MAP_ANONYMOUS,
+ -1, 0);
+ if (extra_base == MAP_FAILED) {
+ ERROR("[ %5d - failed to extend segment from '%s' @ 0x%08x "
+ "(0x%08x) ]\n", pid, si->name, (unsigned)tmp,
+ extra_len);
+ goto fail;
+ }
+ /* TODO: Check if we need to memset-0 this region.
+ * Anonymous mappings are zero-filled copy-on-writes, so we
+ * shouldn't need to. */
+ TRACE("[ %5d - Segment from '%s' extended @ 0x%08x "
+ "(0x%08x)\n", pid, si->name, (unsigned)extra_base,
+ extra_len);
+ }
+ /* set the len here to show the full extent of the segment we
+ * just loaded, mostly for debugging */
+ len = (((unsigned)base + phdr->p_vaddr + phdr->p_memsz +
+ PAGE_SIZE - 1) & (~PAGE_MASK)) - (unsigned)pbase;
+ TRACE("[ %5d - Successfully loaded segment from '%s' @ 0x%08x "
+ "(0x%08x). p_vaddr=0x%08x p_offset=0x%08x\n", pid, si->name,
+ (unsigned)pbase, len, phdr->p_vaddr, phdr->p_offset);
+ total_sz += len;
+ /* Make the section writable just in case we'll have to write to
+ * it during relocation (i.e. text segment). However, we will
+ * remember what range of addresses should be write protected.
+ *
+ */
+ if (!(phdr->p_flags & PF_W)) {
+ if ((unsigned)pbase < si->wrprotect_start)
+ si->wrprotect_start = (unsigned)pbase;
+ if (((unsigned)pbase + len) > si->wrprotect_end)
+ si->wrprotect_end = (unsigned)pbase + len;
+ mprotect(pbase, len,
+ PFLAGS_TO_PROT(phdr->p_flags) | PROT_WRITE);
+ }
+ } else if (phdr->p_type == PT_DYNAMIC) {
+ DEBUG_DUMP_PHDR(phdr, "PT_DYNAMIC", pid);
+ /* this segment contains the dynamic linking information */
+ si->dynamic = (unsigned *)(base + phdr->p_vaddr);
+ } else {
+#ifdef ANDROID_ARM_LINKER
+ if (phdr->p_type == PT_ARM_EXIDX) {
+ DEBUG_DUMP_PHDR(phdr, "PT_ARM_EXIDX", pid);
+ /* exidx entries (used for stack unwinding) are 8 bytes each.
+ */
+ si->ARM_exidx = (unsigned *)phdr->p_vaddr;
+ si->ARM_exidx_count = phdr->p_memsz / 8;
+ }
+#endif
+ }
+
+ }
+
+ /* Sanity check */
+ if (total_sz > si->size) {
+ ERROR("%5d - Total length (0x%08x) of mapped segments from '%s' is "
+ "greater than what was allocated (0x%08x). THIS IS BAD!\n",
+ pid, total_sz, si->name, si->size);
+ goto fail;
+ }
+
+ TRACE("[ %5d - Finish loading segments for '%s' @ 0x%08x. "
+ "Total memory footprint: 0x%08x bytes ]\n", pid, si->name,
+ (unsigned)si->base, si->size);
+ return 0;
+
+fail:
+ /* We can just blindly unmap the entire region even though some things
+ * were mapped in originally with anonymous and others could have been
+ * been mapped in from the file before we failed. The kernel will unmap
+ * all the pages in the range, irrespective of how they got there.
+ */
+ munmap((void *)si->base, si->size);
+ si->flags |= FLAG_ERROR;
+ return -1;
+}
+
+/* TODO: Implement this to take care of the fact that Android ARM
+ * ELF objects shove everything into a single loadable segment that has the
+ * write bit set. wr_offset is then used to set non-(data|bss) pages to be
+ * non-writable.
+ */
+#if 0
+static unsigned
+get_wr_offset(int fd, const char *name, Elf32_Ehdr *ehdr)
+{
+ Elf32_Shdr *shdr_start;
+ Elf32_Shdr *shdr;
+ int shdr_sz = ehdr->e_shnum * sizeof(Elf32_Shdr);
+ int cnt;
+ unsigned wr_offset = 0xffffffff;
+
+ shdr_start = mmap(0, shdr_sz, PROT_READ, MAP_PRIVATE, fd,
+ ehdr->e_shoff & (~PAGE_MASK));
+ if (shdr_start == MAP_FAILED) {
+ WARN("%5d - Could not read section header info from '%s'. Will not "
+ "not be able to determine write-protect offset.\n", pid, name);
+ return (unsigned)-1;
+ }
+
+ for(cnt = 0, shdr = shdr_start; cnt < ehdr->e_shnum; ++cnt, ++shdr) {
+ if ((shdr->sh_type != SHT_NULL) && (shdr->sh_flags & SHF_WRITE) &&
+ (shdr->sh_addr < wr_offset)) {
+ wr_offset = shdr->sh_addr;
+ }
+ }
+
+ munmap(shdr_start, shdr_sz);
+ return wr_offset;
+}
+#endif
+
+static soinfo *
+load_library(const char *name)
+{
+ int fd = open_library(name);
+ int cnt;
+ unsigned ext_sz;
+ unsigned req_base;
+ soinfo *si = NULL;
+ Elf32_Ehdr *hdr;
+
+ if(fd == -1)
+ return NULL;
+
+ /* We have to read the ELF header to figure out what to do with this image
+ */
+ if (lseek(fd, 0, SEEK_SET) < 0) {
+ ERROR("lseek() failed!\n");
+ goto fail;
+ }
+
+ if ((cnt = read(fd, &__header[0], PAGE_SIZE)) < 0) {
+ ERROR("read() failed!\n");
+ goto fail;
+ }
+
+ /* Parse the ELF header and get the size of the memory footprint for
+ * the library */
+ req_base = get_lib_extents(fd, name, &__header[0], &ext_sz);
+ if (req_base == (unsigned)-1)
+ goto fail;
+ TRACE("[ %5d - '%s' (%s) wants base=0x%08x sz=0x%08x ]\n", pid, name,
+ (req_base ? "prelinked" : "not pre-linked"), req_base, ext_sz);
+
+ /* Now configure the soinfo struct where we'll store all of our data
+ * for the ELF object. If the loading fails, we waste the entry, but
+ * same thing would happen if we failed during linking. Configuring the
+ * soinfo struct here is a lot more convenient.
+ */
+ si = alloc_info(name);
+ if (si == NULL)
+ goto fail;
+
+ /* Carve out a chunk of memory where we will map in the individual
+ * segments */
+ si->base = req_base;
+ si->size = ext_sz;
+ si->flags = 0;
+ si->entry = 0;
+ si->dynamic = (unsigned *)-1;
+ if (alloc_mem_region(si) < 0)
+ goto fail;
+
+ TRACE("[ %5d allocated memory for %s @ %p (0x%08x) ]\n",
+ pid, name, (void *)si->base, (unsigned) ext_sz);
+
+ /* Now actually load the library's segments into right places in memory */
+ if (load_segments(fd, &__header[0], si) < 0) {
+ if (si->ba_index >= 0) {
+ ba_free(si->ba_index);
+ si->ba_index = -1;
+ }
+ goto fail;
+ }
+
+ /* this might not be right. Technically, we don't even need this info
+ * once we go through 'load_segments'. */
+ hdr = (Elf32_Ehdr *)si->base;
+ si->phdr = (Elf32_Phdr *)((unsigned char *)si->base + hdr->e_phoff);
+ si->phnum = hdr->e_phnum;
+ /**/
+
+ close(fd);
+ return si;
+
+fail:
+ if (si) free_info(si);
+ close(fd);
+ return NULL;
+}
+
+static soinfo *
+init_library(soinfo *si)
+{
+ unsigned wr_offset = 0xffffffff;
+
+ /* At this point we know that whatever is loaded @ base is a valid ELF
+ * shared library whose segments are properly mapped in. */
+ TRACE("[ %5d init_library base=0x%08x sz=0x%08x name='%s') ]\n",
+ pid, si->base, si->size, si->name);
+
+ if (si->base < LIBBASE || si->base >= LIBLAST)
+ si->flags |= FLAG_PRELINKED;
+
+ if(link_image(si, wr_offset)) {
+ /* We failed to link. However, we can only restore libbase
+ ** if no additional libraries have moved it since we updated it.
+ */
+ munmap((void *)si->base, si->size);
+ return NULL;
+ }
+
+ return si;
+}
+
+soinfo *find_library(const char *name)
+{
+ soinfo *si;
+
+ for(si = solist; si != 0; si = si->next){
+ if(!strcmp(name, si->name)) {
+ if(si->flags & FLAG_ERROR) return 0;
+ if(si->flags & FLAG_LINKED) return si;
+ ERROR("OOPS: %5d recursive link to '%s'\n", pid, si->name);
+ return 0;
+ }
+ }
+
+ TRACE("[ %5d '%s' has not been loaded yet. Locating...]\n", pid, name);
+ si = load_library(name);
+ if(si == NULL)
+ return NULL;
+ return init_library(si);
+}
+
+/* TODO:
+ * notify gdb of unload
+ * for non-prelinked libraries, find a way to decrement libbase
+ */
+static void call_destructors(soinfo *si);
+unsigned unload_library(soinfo *si)
+{
+ unsigned *d;
+ if (si->refcount == 1) {
+ TRACE("%5d unloading '%s'\n", pid, si->name);
+ call_destructors(si);
+
+ for(d = si->dynamic; *d; d += 2) {
+ if(d[0] == DT_NEEDED){
+ TRACE("%5d %s needs to unload %s\n", pid,
+ si->name, si->strtab + d[1]);
+ soinfo *lsi = find_library(si->strtab + d[1]);
+ if(lsi)
+ unload_library(lsi);
+ else
+ ERROR("%5d could not unload '%s'\n",
+ pid, si->strtab + d[1]);
+ }
+ }
+
+ munmap((char *)si->base, si->size);
+ if (si->ba_index >= 0) {
+ PRINT("%5d releasing library '%s' address space at %08x "\
+ "through buddy allocator.\n",
+ pid, si->name, si->base);
+ ba_free(si->ba_index);
+ }
+ free_info(si);
+ si->refcount = 0;
+ }
+ else {
+ si->refcount--;
+ PRINT("%5d not unloading '%s', decrementing refcount to %d\n",
+ pid, si->name, si->refcount);
+ }
+ return si->refcount;
+}
+
+/* TODO: don't use unsigned for addrs below. It works, but is not
+ * ideal. They should probably be either uint32_t, Elf32_Addr, or unsigned
+ * long.
+ */
+static int reloc_library(soinfo *si, Elf32_Rel *rel, unsigned count)
+{
+ Elf32_Sym *symtab = si->symtab;
+ const char *strtab = si->strtab;
+ Elf32_Sym *s;
+ unsigned base;
+ Elf32_Rel *start = rel;
+ unsigned idx;
+
+ for (idx = 0; idx < count; ++idx) {
+ unsigned type = ELF32_R_TYPE(rel->r_info);
+ unsigned sym = ELF32_R_SYM(rel->r_info);
+ unsigned reloc = (unsigned)(rel->r_offset + si->base);
+ unsigned sym_addr = 0;
+ char *sym_name = NULL;
+
+ DEBUG("%5d Processing '%s' relocation at index %d\n", pid,
+ si->name, idx);
+ if(sym != 0) {
+ s = _do_lookup(si, strtab + symtab[sym].st_name, &base);
+ if(s == 0) {
+ ERROR("%5d cannot locate '%s'...\n", pid, sym_name);
+ return -1;
+ }
+#if 0
+ if((base == 0) && (si->base != 0)){
+ /* linking from libraries to main image is bad */
+ ERROR("%5d cannot locate '%s'...\n",
+ pid, strtab + symtab[sym].st_name);
+ return -1;
+ }
+#endif
+ if ((s->st_shndx == SHN_UNDEF) && (s->st_value != 0)) {
+ ERROR("%5d In '%s', shndx=%d && value=0x%08x. We do not "
+ "handle this yet\n", pid, si->name, s->st_shndx,
+ s->st_value);
+ return -1;
+ }
+ sym_addr = (unsigned)(s->st_value + base);
+ sym_name = (char *)(strtab + symtab[sym].st_name);
+ COUNT_RELOC(RELOC_SYMBOL);
+ } else {
+ s = 0;
+ }
+
+/* TODO: This is ugly. Split up the relocations by arch into
+ * different files.
+ */
+ switch(type){
+#if defined(ANDROID_ARM_LINKER)
+ case R_ARM_JUMP_SLOT:
+ COUNT_RELOC(RELOC_ABSOLUTE);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "%5d RELO JMP_SLOT %08x <- %08x %s\n", pid,
+ reloc, sym_addr, sym_name);
+ *((unsigned*)reloc) = sym_addr;
+ break;
+ case R_ARM_GLOB_DAT:
+ COUNT_RELOC(RELOC_ABSOLUTE);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "%5d RELO GLOB_DAT %08x <- %08x %s\n", pid,
+ reloc, sym_addr, sym_name);
+ *((unsigned*)reloc) = sym_addr;
+ break;
+ case R_ARM_ABS32:
+ COUNT_RELOC(RELOC_ABSOLUTE);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "%5d RELO ABS %08x <- %08x %s\n", pid,
+ reloc, sym_addr, sym_name);
+ *((unsigned*)reloc) += sym_addr;
+ break;
+#elif defined(ANDROID_X86_LINKER)
+ case R_386_JUMP_SLOT:
+ COUNT_RELOC(RELOC_ABSOLUTE);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "%5d RELO JMP_SLOT %08x <- %08x %s\n", pid,
+ reloc, sym_addr, sym_name);
+ *((unsigned*)reloc) = sym_addr;
+ break;
+ case R_386_GLOB_DAT:
+ COUNT_RELOC(RELOC_ABSOLUTE);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "%5d RELO GLOB_DAT %08x <- %08x %s\n", pid,
+ reloc, sym_addr, sym_name);
+ *((unsigned*)reloc) = sym_addr;
+ break;
+#endif /* ANDROID_*_LINKER */
+
+#if defined(ANDROID_ARM_LINKER)
+ case R_ARM_RELATIVE:
+#elif defined(ANDROID_X86_LINKER)
+ case R_386_RELATIVE:
+#endif /* ANDROID_*_LINKER */
+ COUNT_RELOC(RELOC_RELATIVE);
+ MARK(rel->r_offset);
+ if(sym){
+ ERROR("%5d odd RELATIVE form...\n", pid);
+ return -1;
+ }
+ TRACE_TYPE(RELO, "%5d RELO RELATIVE %08x <- +%08x\n", pid,
+ reloc, si->base);
+ *((unsigned*)reloc) += si->base;
+ break;
+
+#if defined(ANDROID_X86_LINKER)
+ case R_386_32:
+ COUNT_RELOC(RELOC_RELATIVE);
+ MARK(rel->r_offset);
+
+ TRACE_TYPE(RELO, "%5d RELO R_386_32 %08x <- +%08x %s\n", pid,
+ reloc, sym_addr, sym_name);
+ *((unsigned *)reloc) += (unsigned)sym_addr;
+ break;
+
+ case R_386_PC32:
+ COUNT_RELOC(RELOC_RELATIVE);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "%5d RELO R_386_PC32 %08x <- "
+ "+%08x (%08x - %08x) %s\n", pid, reloc,
+ (sym_addr - reloc), sym_addr, reloc, sym_name);
+ *((unsigned *)reloc) += (unsigned)(sym_addr - reloc);
+ break;
+#endif /* ANDROID_X86_LINKER */
+
+#ifdef ANDROID_ARM_LINKER
+ case R_ARM_COPY:
+ COUNT_RELOC(RELOC_COPY);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "%5d RELO %08x <- %d @ %08x %s\n", pid,
+ reloc, s->st_size, sym_addr, sym_name);
+ memcpy((void*)reloc, (void*)sym_addr, s->st_size);
+ break;
+#endif /* ANDROID_ARM_LINKER */
+
+ default:
+ ERROR("%5d unknown reloc type %d @ %p (%d)\n",
+ pid, type, rel, (int) (rel - start));
+ return -1;
+ }
+ rel++;
+ }
+ return 0;
+}
+
+static void call_array(unsigned *ctor, int count)
+{
+ int n;
+ for(n = count; n > 0; n--){
+ TRACE("[ %5d Looking at ctor *0x%08x == 0x%08x ]\n", pid,
+ (unsigned)ctor, (unsigned)*ctor);
+ void (*func)() = (void (*)()) *ctor++;
+ if(((int) func == 0) || ((int) func == -1)) continue;
+ TRACE("[ %5d Calling func @ 0x%08x ]\n", pid, (unsigned)func);
+ func();
+ }
+}
+
+static void call_constructors(soinfo *si)
+{
+ /* TODO: THE ORIGINAL CODE SEEMED TO CALL THE INIT FUNCS IN THE WRONG ORDER.
+ * Old order: init, init_array, preinit_array..
+ * Correct order: preinit_array, init, init_array.
+ * Verify WHY.
+ */
+
+ if (si->flags & FLAG_EXE) {
+ TRACE("[ %5d Calling preinit_array @ 0x%08x [%d] for '%s' ]\n",
+ pid, (unsigned)si->preinit_array, si->preinit_array_count,
+ si->name);
+ call_array(si->preinit_array, si->preinit_array_count);
+ TRACE("[ %5d Done calling preinit_array for '%s' ]\n", pid, si->name);
+ } else {
+ if (si->preinit_array) {
+ ERROR("%5d Shared library '%s' has a preinit_array table @ 0x%08x."
+ " This is INVALID.\n", pid, si->name,
+ (unsigned)si->preinit_array);
+ }
+ }
+
+ // If we have an init section, then we should call it now, to make sure
+ // that all the funcs in the .ctors section get run.
+ // Note: For ARM, we shouldn't have a .ctor section (should be empty)
+ // when we have an (pre)init_array section, but let's be compatible with
+ // old (non-eabi) binaries and try the _init (DT_INIT) anyway.
+ if (si->init_func) {
+ TRACE("[ %5d Calling init_func @ 0x%08x for '%s' ]\n", pid,
+ (unsigned)si->init_func, si->name);
+ si->init_func();
+ TRACE("[ %5d Done calling init_func for '%s' ]\n", pid, si->name);
+ }
+
+ if (si->init_array) {
+ TRACE("[ %5d Calling init_array @ 0x%08x [%d] for '%s' ]\n", pid,
+ (unsigned)si->init_array, si->init_array_count, si->name);
+ call_array(si->init_array, si->init_array_count);
+ TRACE("[ %5d Done calling init_array for '%s' ]\n", pid, si->name);
+ }
+}
+
+static void call_destructors(soinfo *si)
+{
+ if (si->fini_array) {
+ TRACE("[ %5d Calling fini_array @ 0x%08x [%d] for '%s' ]\n", pid,
+ (unsigned)si->fini_array, si->fini_array_count, si->name);
+ call_array(si->fini_array, si->fini_array_count);
+ TRACE("[ %5d Done calling fini_array for '%s' ]\n", pid, si->name);
+ }
+
+ // If we have an fini section, then we should call it now, to make sure
+ // that all the funcs in the .dtors section get run.
+ // Note: For ARM, we shouldn't have a .dtor section (should be empty)
+ // when we have an fini_array section, but let's be compatible with
+ // old (non-eabi) binaries and try the _fini (DT_FINI) anyway.
+ if (si->fini_func) {
+ TRACE("[ %5d Calling fini_func @ 0x%08x for '%s' ]\n", pid,
+ (unsigned)si->fini_func, si->name);
+ si->fini_func();
+ TRACE("[ %5d Done calling fini_func for '%s' ]\n", pid, si->name);
+ }
+}
+
+/* Force any of the closed stdin, stdout and stderr to be associated with
+ /dev/null. */
+static int nullify_closed_stdio (void)
+{
+ int dev_null, i, status;
+ int return_value = 0;
+
+ dev_null = open("/dev/null", O_RDWR);
+ if (dev_null < 0) {
+ ERROR("Cannot open /dev/null.\n");
+ return -1;
+ }
+ TRACE("[ %5d Opened /dev/null file-descriptor=%d]\n", pid, dev_null);
+
+ /* If any of the stdio file descriptors is valid and not associated
+ with /dev/null, dup /dev/null to it. */
+ for (i = 0; i < 3; i++) {
+ /* If it is /dev/null already, we are done. */
+ if (i == dev_null)
+ continue;
+
+ TRACE("[ %5d Nullifying stdio file descriptor %d]\n", pid, i);
+ /* The man page of fcntl does not say that fcntl(..,F_GETFL)
+ can be interrupted but we do this just to be safe. */
+ do {
+ status = fcntl(i, F_GETFL);
+ } while (status < 0 && errno == EINTR);
+
+ /* If file is openned, we are good. */
+ if (status >= 0)
+ continue;
+
+ /* The only error we allow is that the file descriptor does not
+ exist, in which case we dup /dev/null to it. */
+ if (errno != EBADF) {
+ ERROR("nullify_stdio: unhandled error %s\n", strerror(errno));
+ return_value = -1;
+ continue;
+ }
+
+ /* Try dupping /dev/null to this stdio file descriptor and
+ repeat if there is a signal. Note that any errors in closing
+ the stdio descriptor are lost. */
+ do {
+ status = dup2(dev_null, i);
+ } while (status < 0 && errno == EINTR);
+
+ if (status < 0) {
+ ERROR("nullify_stdio: dup2 error %s\n", strerror(errno));
+ return_value = -1;
+ continue;
+ }
+ }
+
+ /* If /dev/null is not one of the stdio file descriptors, close it. */
+ if (dev_null > 2) {
+ TRACE("[ %5d Closing /dev/null file-descriptor=%d]\n", pid, dev_null);
+ do {
+ status = close(dev_null);
+ } while (status < 0 && errno == EINTR);
+
+ if (status < 0) {
+ ERROR("nullify_stdio: close error %s\n", strerror(errno));
+ return_value = -1;
+ }
+ }
+
+ return return_value;
+}
+
+static int link_image(soinfo *si, unsigned wr_offset)
+{
+ unsigned *d;
+ Elf32_Phdr *phdr = si->phdr;
+ int phnum = si->phnum;
+
+ INFO("[ %5d linking %s ]\n", pid, si->name);
+ DEBUG("%5d si->base = 0x%08x si->flags = 0x%08x\n", pid,
+ si->base, si->flags);
+
+ if (si->flags & FLAG_EXE) {
+ /* Locate the needed program segments (DYNAMIC/ARM_EXIDX) for
+ * linkage info if this is the executable. If this was a
+ * dynamic lib, that would have been done at load time.
+ *
+ * TODO: It's unfortunate that small pieces of this are
+ * repeated from the load_library routine. Refactor this just
+ * slightly to reuse these bits.
+ */
+ si->size = 0;
+ for(; phnum > 0; --phnum, ++phdr) {
+#ifdef ANDROID_ARM_LINKER
+ if(phdr->p_type == PT_ARM_EXIDX) {
+ /* exidx entries (used for stack unwinding) are 8 bytes each.
+ */
+ si->ARM_exidx = (unsigned *)phdr->p_vaddr;
+ si->ARM_exidx_count = phdr->p_memsz / 8;
+ }
+#endif
+ if (phdr->p_type == PT_LOAD) {
+ /* For the executable, we use the si->size field only in
+ dl_unwind_find_exidx(), so the meaning of si->size
+ is not the size of the executable; it is the last
+ virtual address of the loadable part of the executable;
+ since si->base == 0 for an executable, we use the
+ range [0, si->size) to determine whether a PC value
+ falls within the executable section. Of course, if
+ a value is below phdr->p_vaddr, it's not in the
+ executable section, but a) we shouldn't be asking for
+ such a value anyway, and b) if we have to provide
+ an EXIDX for such a value, then the executable's
+ EXIDX is probably the better choice.
+ */
+ DEBUG_DUMP_PHDR(phdr, "PT_LOAD", pid);
+ if (phdr->p_vaddr + phdr->p_memsz > si->size)
+ si->size = phdr->p_vaddr + phdr->p_memsz;
+ /* try to remember what range of addresses should be write
+ * protected */
+ if (!(phdr->p_flags & PF_W)) {
+ unsigned _end;
+
+ if (phdr->p_vaddr < si->wrprotect_start)
+ si->wrprotect_start = phdr->p_vaddr;
+ _end = (((phdr->p_vaddr + phdr->p_memsz + PAGE_SIZE - 1) &
+ (~PAGE_MASK)));
+ if (_end > si->wrprotect_end)
+ si->wrprotect_end = _end;
+ }
+ } else if (phdr->p_type == PT_DYNAMIC) {
+ if (si->dynamic != (unsigned *)-1) {
+ ERROR("%5d multiple PT_DYNAMIC segments found in '%s'. "
+ "Segment at 0x%08x, previously one found at 0x%08x\n",
+ pid, si->name, si->base + phdr->p_vaddr,
+ (unsigned)si->dynamic);
+ goto fail;
+ }
+ DEBUG_DUMP_PHDR(phdr, "PT_DYNAMIC", pid);
+ si->dynamic = (unsigned *) (si->base + phdr->p_vaddr);
+ }
+ }
+ }
+
+ if (si->dynamic == (unsigned *)-1) {
+ ERROR("%5d missing PT_DYNAMIC?!\n", pid);
+ goto fail;
+ }
+
+ DEBUG("%5d dynamic = %p\n", pid, si->dynamic);
+
+ /* extract useful information from dynamic section */
+ for(d = si->dynamic; *d; d++){
+ DEBUG("%5d d = %p, d[0] = 0x%08x d[1] = 0x%08x\n", pid, d, d[0], d[1]);
+ switch(*d++){
+ case DT_HASH:
+ si->nbucket = ((unsigned *) (si->base + *d))[0];
+ si->nchain = ((unsigned *) (si->base + *d))[1];
+ si->bucket = (unsigned *) (si->base + *d + 8);
+ si->chain = (unsigned *) (si->base + *d + 8 + si->nbucket * 4);
+ break;
+ case DT_STRTAB:
+ si->strtab = (const char *) (si->base + *d);
+ break;
+ case DT_SYMTAB:
+ si->symtab = (Elf32_Sym *) (si->base + *d);
+ break;
+ case DT_PLTREL:
+ if(*d != DT_REL) {
+ ERROR("DT_RELA not supported\n");
+ goto fail;
+ }
+ break;
+ case DT_JMPREL:
+ si->plt_rel = (Elf32_Rel*) (si->base + *d);
+ break;
+ case DT_PLTRELSZ:
+ si->plt_rel_count = *d / 8;
+ break;
+ case DT_REL:
+ si->rel = (Elf32_Rel*) (si->base + *d);
+ break;
+ case DT_RELSZ:
+ si->rel_count = *d / 8;
+ break;
+ case DT_PLTGOT:
+ /* Save this in case we decide to do lazy binding. We don't yet. */
+ si->plt_got = (unsigned *)(si->base + *d);
+ break;
+ case DT_DEBUG:
+ // Set the DT_DEBUG entry to the addres of _r_debug for GDB
+ *d = (int) &_r_debug;
+ break;
+ case DT_RELA:
+ ERROR("%5d DT_RELA not supported\n", pid);
+ goto fail;
+ case DT_INIT:
+ si->init_func = (void (*)(void))(si->base + *d);
+ DEBUG("%5d %s constructors (init func) found at %p\n",
+ pid, si->name, si->init_func);
+ break;
+ case DT_FINI:
+ si->fini_func = (void (*)(void))(si->base + *d);
+ DEBUG("%5d %s destructors (fini func) found at %p\n",
+ pid, si->name, si->fini_func);
+ break;
+ case DT_INIT_ARRAY:
+ si->init_array = (unsigned *)(si->base + *d);
+ DEBUG("%5d %s constructors (init_array) found at %p\n",
+ pid, si->name, si->init_array);
+ break;
+ case DT_INIT_ARRAYSZ:
+ si->init_array_count = ((unsigned)*d) / sizeof(Elf32_Addr);
+ break;
+ case DT_FINI_ARRAY:
+ si->fini_array = (unsigned *)(si->base + *d);
+ DEBUG("%5d %s destructors (fini_array) found at %p\n",
+ pid, si->name, si->fini_array);
+ break;
+ case DT_FINI_ARRAYSZ:
+ si->fini_array_count = ((unsigned)*d) / sizeof(Elf32_Addr);
+ break;
+ case DT_PREINIT_ARRAY:
+ si->preinit_array = (unsigned *)(si->base + *d);
+ DEBUG("%5d %s constructors (preinit_array) found at %p\n",
+ pid, si->name, si->preinit_array);
+ break;
+ case DT_PREINIT_ARRAYSZ:
+ si->preinit_array_count = ((unsigned)*d) / sizeof(Elf32_Addr);
+ break;
+ case DT_TEXTREL:
+ /* TODO: make use of this. */
+ /* this means that we might have to write into where the text
+ * segment was loaded during relocation... Do something with
+ * it.
+ */
+ DEBUG("%5d Text segment should be writable during relocation.\n",
+ pid);
+ break;
+ }
+ }
+
+ DEBUG("%5d si->base = 0x%08x, si->strtab = %p, si->symtab = %p\n",
+ pid, si->base, si->strtab, si->symtab);
+
+ if((si->strtab == 0) || (si->symtab == 0)) {
+ ERROR("%5d missing essential tables\n", pid);
+ goto fail;
+ }
+
+ for(d = si->dynamic; *d; d += 2) {
+ if(d[0] == DT_NEEDED){
+ DEBUG("%5d %s needs %s\n", pid, si->name, si->strtab + d[1]);
+ soinfo *lsi = find_library(si->strtab + d[1]);
+ if(lsi == 0) {
+ ERROR("%5d could not load '%s'\n", pid, si->strtab + d[1]);
+ goto fail;
+ }
+ lsi->refcount++;
+ }
+ }
+
+ if(si->plt_rel) {
+ DEBUG("[ %5d relocating %s plt ]\n", pid, si->name );
+ if(reloc_library(si, si->plt_rel, si->plt_rel_count))
+ goto fail;
+ }
+ if(si->rel) {
+ DEBUG("[ %5d relocating %s ]\n", pid, si->name );
+ if(reloc_library(si, si->rel, si->rel_count))
+ goto fail;
+ }
+
+ si->flags |= FLAG_LINKED;
+ DEBUG("[ %5d finished linking %s ]\n", pid, si->name);
+
+#if 0
+ /* This is the way that the old dynamic linker did protection of
+ * non-writable areas. It would scan section headers and find where
+ * .text ended (rather where .data/.bss began) and assume that this is
+ * the upper range of the non-writable area. This is too coarse,
+ * and is kept here for reference until we fully move away from single
+ * segment elf objects. See the code in get_wr_offset (also #if'd 0)
+ * that made this possible.
+ */
+ if(wr_offset < 0xffffffff){
+ mprotect((void*) si->base, wr_offset, PROT_READ | PROT_EXEC);
+ }
+#else
+ /* TODO: Verify that this does the right thing in all cases, as it
+ * presently probably does not. It is possible that an ELF image will
+ * come with multiple read-only segments. What we ought to do is scan
+ * the program headers again and mprotect all the read-only segments.
+ * To prevent re-scanning the program header, we would have to build a
+ * list of loadable segments in si, and then scan that instead. */
+ if (si->wrprotect_start != 0xffffffff && si->wrprotect_end != 0) {
+ mprotect((void *)si->wrprotect_start,
+ si->wrprotect_end - si->wrprotect_start,
+ PROT_READ | PROT_EXEC);
+ }
+#endif
+
+ /* If this is a SET?ID program, dup /dev/null to opened stdin,
+ stdout and stderr to close a security hole described in:
+
+ ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-02:23.stdio.asc
+
+ */
+ if (getuid() != geteuid() || getgid() != getegid())
+ nullify_closed_stdio ();
+ call_constructors(si);
+ notify_gdb_of_load(si);
+ return 0;
+
+fail:
+ ERROR("failed to link %s\n", si->name);
+ si->flags |= FLAG_ERROR;
+ return -1;
+}
+
+int main(int argc, char **argv)
+{
+ return 0;
+}
+
+#define ANDROID_TLS_SLOTS BIONIC_TLS_SLOTS
+
+static void * __tls_area[ANDROID_TLS_SLOTS];
+
+unsigned __linker_init(unsigned **elfdata)
+{
+ static soinfo linker_soinfo;
+
+ int argc = (int) *elfdata;
+ char **argv = (char**) (elfdata + 1);
+ unsigned *vecs = (unsigned*) (argv + argc + 1);
+ soinfo *si;
+ struct link_map * map;
+
+ pid = getpid();
+
+#if TIMING
+ struct timeval t0, t1;
+ gettimeofday(&t0, 0);
+#endif
+
+ __set_tls(__tls_area);
+ ((unsigned *)__get_tls())[TLS_SLOT_THREAD_ID] = gettid();
+
+ debugger_init();
+
+ /* skip past the environment */
+ while(vecs[0] != 0) {
+ if(!strncmp((char*) vecs[0], "DEBUG=", 6)) {
+ debug_verbosity = atoi(((char*) vecs[0]) + 6);
+ }
+ vecs++;
+ }
+ vecs++;
+
+ INFO("[ android linker & debugger ]\n");
+ DEBUG("%5d elfdata @ 0x%08x\n", pid, (unsigned)elfdata);
+
+ si = alloc_info(argv[0]);
+ if(si == 0) {
+ exit(-1);
+ }
+
+ /* bootstrap the link map, the main exe always needs to be first */
+ si->flags |= FLAG_EXE;
+ map = &(si->linkmap);
+
+ map->l_addr = 0;
+ map->l_name = argv[0];
+ map->l_prev = NULL;
+ map->l_next = NULL;
+
+ _r_debug.r_map = map;
+ r_debug_tail = map;
+
+ /* gdb expects the linker to be in the debug shared object list,
+ * and we need to make sure that the reported load address is zero.
+ * Without this, gdb gets the wrong idea of where rtld_db_dlactivity()
+ * is. Don't use alloc_info(), because the linker shouldn't
+ * be on the soinfo list.
+ */
+ strcpy((char*) linker_soinfo.name, "/system/bin/linker");
+ linker_soinfo.flags = 0;
+ linker_soinfo.base = 0; // This is the important part; must be zero.
+ insert_soinfo_into_debug_map(&linker_soinfo);
+
+ /* extract information passed from the kernel */
+ while(vecs[0] != 0){
+ switch(vecs[0]){
+ case AT_PHDR:
+ si->phdr = (Elf32_Phdr*) vecs[1];
+ break;
+ case AT_PHNUM:
+ si->phnum = (int) vecs[1];
+ break;
+ case AT_ENTRY:
+ si->entry = vecs[1];
+ break;
+ }
+ vecs += 2;
+ }
+
+ ba_init();
+
+ si->base = 0;
+ si->dynamic = (unsigned *)-1;
+ si->wrprotect_start = 0xffffffff;
+ si->wrprotect_end = 0;
+
+ if(link_image(si, 0)){
+ ERROR("CANNOT LINK EXECUTABLE '%s'\n", argv[0]);
+ exit(-1);
+ }
+
+#if TIMING
+ gettimeofday(&t1,NULL);
+ PRINT("LINKER TIME: %s: %d microseconds\n", argv[0], (int) (
+ (((long long)t1.tv_sec * 1000000LL) + (long long)t1.tv_usec) -
+ (((long long)t0.tv_sec * 1000000LL) + (long long)t0.tv_usec)
+ ));
+#endif
+#if STATS
+ PRINT("RELO STATS: %s: %d abs, %d rel, %d copy, %d symbol\n", argv[0],
+ linker_stats.reloc[RELOC_ABSOLUTE],
+ linker_stats.reloc[RELOC_RELATIVE],
+ linker_stats.reloc[RELOC_COPY],
+ linker_stats.reloc[RELOC_SYMBOL]);
+#endif
+#if COUNT_PAGES
+ {
+ unsigned n;
+ unsigned i;
+ unsigned count = 0;
+ for(n = 0; n < 4096; n++){
+ if(bitmask[n]){
+ unsigned x = bitmask[n];
+ for(i = 0; i < 8; i++){
+ if(x & 1) count++;
+ x >>= 1;
+ }
+ }
+ }
+ PRINT("PAGES MODIFIED: %s: %d (%dKB)\n", argv[0], count, count * 4);
+ }
+#endif
+
+#if TIMING || STATS || COUNT_PAGES
+ fflush(stdout);
+#endif
+
+ TRACE("[ %5d Ready to execute '%s' @ 0x%08x ]\n", pid, si->name,
+ si->entry);
+ return si->entry;
+}