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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/binfmt_elf.c
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/binfmt_elf.c')
-rw-r--r--fs/binfmt_elf.c1677
1 files changed, 1677 insertions, 0 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
new file mode 100644
index 000000000000..76ec9d8939ff
--- /dev/null
+++ b/fs/binfmt_elf.c
@@ -0,0 +1,1677 @@
+/*
+ * linux/fs/binfmt_elf.c
+ *
+ * These are the functions used to load ELF format executables as used
+ * on SVr4 machines. Information on the format may be found in the book
+ * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
+ * Tools".
+ *
+ * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/stat.h>
+#include <linux/time.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/a.out.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/binfmts.h>
+#include <linux/string.h>
+#include <linux/file.h>
+#include <linux/fcntl.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/shm.h>
+#include <linux/personality.h>
+#include <linux/elfcore.h>
+#include <linux/init.h>
+#include <linux/highuid.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/compiler.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/random.h>
+
+#include <asm/uaccess.h>
+#include <asm/param.h>
+#include <asm/page.h>
+
+#include <linux/elf.h>
+
+static int load_elf_binary(struct linux_binprm * bprm, struct pt_regs * regs);
+static int load_elf_library(struct file*);
+static unsigned long elf_map (struct file *, unsigned long, struct elf_phdr *, int, int);
+extern int dump_fpu (struct pt_regs *, elf_fpregset_t *);
+
+#ifndef elf_addr_t
+#define elf_addr_t unsigned long
+#endif
+
+/*
+ * If we don't support core dumping, then supply a NULL so we
+ * don't even try.
+ */
+#ifdef USE_ELF_CORE_DUMP
+static int elf_core_dump(long signr, struct pt_regs * regs, struct file * file);
+#else
+#define elf_core_dump NULL
+#endif
+
+#if ELF_EXEC_PAGESIZE > PAGE_SIZE
+# define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
+#else
+# define ELF_MIN_ALIGN PAGE_SIZE
+#endif
+
+#ifndef ELF_CORE_EFLAGS
+#define ELF_CORE_EFLAGS 0
+#endif
+
+#define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
+#define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
+#define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
+
+static struct linux_binfmt elf_format = {
+ .module = THIS_MODULE,
+ .load_binary = load_elf_binary,
+ .load_shlib = load_elf_library,
+ .core_dump = elf_core_dump,
+ .min_coredump = ELF_EXEC_PAGESIZE
+};
+
+#define BAD_ADDR(x) ((unsigned long)(x) > TASK_SIZE)
+
+static int set_brk(unsigned long start, unsigned long end)
+{
+ start = ELF_PAGEALIGN(start);
+ end = ELF_PAGEALIGN(end);
+ if (end > start) {
+ unsigned long addr;
+ down_write(&current->mm->mmap_sem);
+ addr = do_brk(start, end - start);
+ up_write(&current->mm->mmap_sem);
+ if (BAD_ADDR(addr))
+ return addr;
+ }
+ current->mm->start_brk = current->mm->brk = end;
+ return 0;
+}
+
+
+/* We need to explicitly zero any fractional pages
+ after the data section (i.e. bss). This would
+ contain the junk from the file that should not
+ be in memory */
+
+
+static int padzero(unsigned long elf_bss)
+{
+ unsigned long nbyte;
+
+ nbyte = ELF_PAGEOFFSET(elf_bss);
+ if (nbyte) {
+ nbyte = ELF_MIN_ALIGN - nbyte;
+ if (clear_user((void __user *) elf_bss, nbyte))
+ return -EFAULT;
+ }
+ return 0;
+}
+
+/* Let's use some macros to make this stack manipulation a litle clearer */
+#ifdef CONFIG_STACK_GROWSUP
+#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
+#define STACK_ROUND(sp, items) \
+ ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
+#define STACK_ALLOC(sp, len) ({ elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; old_sp; })
+#else
+#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
+#define STACK_ROUND(sp, items) \
+ (((unsigned long) (sp - items)) &~ 15UL)
+#define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
+#endif
+
+static int
+create_elf_tables(struct linux_binprm *bprm, struct elfhdr * exec,
+ int interp_aout, unsigned long load_addr,
+ unsigned long interp_load_addr)
+{
+ unsigned long p = bprm->p;
+ int argc = bprm->argc;
+ int envc = bprm->envc;
+ elf_addr_t __user *argv;
+ elf_addr_t __user *envp;
+ elf_addr_t __user *sp;
+ elf_addr_t __user *u_platform;
+ const char *k_platform = ELF_PLATFORM;
+ int items;
+ elf_addr_t *elf_info;
+ int ei_index = 0;
+ struct task_struct *tsk = current;
+
+ /*
+ * If this architecture has a platform capability string, copy it
+ * to userspace. In some cases (Sparc), this info is impossible
+ * for userspace to get any other way, in others (i386) it is
+ * merely difficult.
+ */
+
+ u_platform = NULL;
+ if (k_platform) {
+ size_t len = strlen(k_platform) + 1;
+
+ /*
+ * In some cases (e.g. Hyper-Threading), we want to avoid L1
+ * evictions by the processes running on the same package. One
+ * thing we can do is to shuffle the initial stack for them.
+ */
+
+ p = arch_align_stack(p);
+
+ u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
+ if (__copy_to_user(u_platform, k_platform, len))
+ return -EFAULT;
+ }
+
+ /* Create the ELF interpreter info */
+ elf_info = (elf_addr_t *) current->mm->saved_auxv;
+#define NEW_AUX_ENT(id, val) \
+ do { elf_info[ei_index++] = id; elf_info[ei_index++] = val; } while (0)
+
+#ifdef ARCH_DLINFO
+ /*
+ * ARCH_DLINFO must come first so PPC can do its special alignment of
+ * AUXV.
+ */
+ ARCH_DLINFO;
+#endif
+ NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
+ NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
+ NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
+ NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
+ NEW_AUX_ENT(AT_PHENT, sizeof (struct elf_phdr));
+ NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
+ NEW_AUX_ENT(AT_BASE, interp_load_addr);
+ NEW_AUX_ENT(AT_FLAGS, 0);
+ NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
+ NEW_AUX_ENT(AT_UID, (elf_addr_t) tsk->uid);
+ NEW_AUX_ENT(AT_EUID, (elf_addr_t) tsk->euid);
+ NEW_AUX_ENT(AT_GID, (elf_addr_t) tsk->gid);
+ NEW_AUX_ENT(AT_EGID, (elf_addr_t) tsk->egid);
+ NEW_AUX_ENT(AT_SECURE, (elf_addr_t) security_bprm_secureexec(bprm));
+ if (k_platform) {
+ NEW_AUX_ENT(AT_PLATFORM, (elf_addr_t)(unsigned long)u_platform);
+ }
+ if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
+ NEW_AUX_ENT(AT_EXECFD, (elf_addr_t) bprm->interp_data);
+ }
+#undef NEW_AUX_ENT
+ /* AT_NULL is zero; clear the rest too */
+ memset(&elf_info[ei_index], 0,
+ sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
+
+ /* And advance past the AT_NULL entry. */
+ ei_index += 2;
+
+ sp = STACK_ADD(p, ei_index);
+
+ items = (argc + 1) + (envc + 1);
+ if (interp_aout) {
+ items += 3; /* a.out interpreters require argv & envp too */
+ } else {
+ items += 1; /* ELF interpreters only put argc on the stack */
+ }
+ bprm->p = STACK_ROUND(sp, items);
+
+ /* Point sp at the lowest address on the stack */
+#ifdef CONFIG_STACK_GROWSUP
+ sp = (elf_addr_t __user *)bprm->p - items - ei_index;
+ bprm->exec = (unsigned long) sp; /* XXX: PARISC HACK */
+#else
+ sp = (elf_addr_t __user *)bprm->p;
+#endif
+
+ /* Now, let's put argc (and argv, envp if appropriate) on the stack */
+ if (__put_user(argc, sp++))
+ return -EFAULT;
+ if (interp_aout) {
+ argv = sp + 2;
+ envp = argv + argc + 1;
+ __put_user((elf_addr_t)(unsigned long)argv, sp++);
+ __put_user((elf_addr_t)(unsigned long)envp, sp++);
+ } else {
+ argv = sp;
+ envp = argv + argc + 1;
+ }
+
+ /* Populate argv and envp */
+ p = current->mm->arg_start;
+ while (argc-- > 0) {
+ size_t len;
+ __put_user((elf_addr_t)p, argv++);
+ len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
+ if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
+ return 0;
+ p += len;
+ }
+ if (__put_user(0, argv))
+ return -EFAULT;
+ current->mm->arg_end = current->mm->env_start = p;
+ while (envc-- > 0) {
+ size_t len;
+ __put_user((elf_addr_t)p, envp++);
+ len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
+ if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
+ return 0;
+ p += len;
+ }
+ if (__put_user(0, envp))
+ return -EFAULT;
+ current->mm->env_end = p;
+
+ /* Put the elf_info on the stack in the right place. */
+ sp = (elf_addr_t __user *)envp + 1;
+ if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
+ return -EFAULT;
+ return 0;
+}
+
+#ifndef elf_map
+
+static unsigned long elf_map(struct file *filep, unsigned long addr,
+ struct elf_phdr *eppnt, int prot, int type)
+{
+ unsigned long map_addr;
+
+ down_write(&current->mm->mmap_sem);
+ map_addr = do_mmap(filep, ELF_PAGESTART(addr),
+ eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr), prot, type,
+ eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr));
+ up_write(&current->mm->mmap_sem);
+ return(map_addr);
+}
+
+#endif /* !elf_map */
+
+/* This is much more generalized than the library routine read function,
+ so we keep this separate. Technically the library read function
+ is only provided so that we can read a.out libraries that have
+ an ELF header */
+
+static unsigned long load_elf_interp(struct elfhdr * interp_elf_ex,
+ struct file * interpreter,
+ unsigned long *interp_load_addr)
+{
+ struct elf_phdr *elf_phdata;
+ struct elf_phdr *eppnt;
+ unsigned long load_addr = 0;
+ int load_addr_set = 0;
+ unsigned long last_bss = 0, elf_bss = 0;
+ unsigned long error = ~0UL;
+ int retval, i, size;
+
+ /* First of all, some simple consistency checks */
+ if (interp_elf_ex->e_type != ET_EXEC &&
+ interp_elf_ex->e_type != ET_DYN)
+ goto out;
+ if (!elf_check_arch(interp_elf_ex))
+ goto out;
+ if (!interpreter->f_op || !interpreter->f_op->mmap)
+ goto out;
+
+ /*
+ * If the size of this structure has changed, then punt, since
+ * we will be doing the wrong thing.
+ */
+ if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
+ goto out;
+ if (interp_elf_ex->e_phnum < 1 ||
+ interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
+ goto out;
+
+ /* Now read in all of the header information */
+
+ size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
+ if (size > ELF_MIN_ALIGN)
+ goto out;
+ elf_phdata = (struct elf_phdr *) kmalloc(size, GFP_KERNEL);
+ if (!elf_phdata)
+ goto out;
+
+ retval = kernel_read(interpreter,interp_elf_ex->e_phoff,(char *)elf_phdata,size);
+ error = -EIO;
+ if (retval != size) {
+ if (retval < 0)
+ error = retval;
+ goto out_close;
+ }
+
+ eppnt = elf_phdata;
+ for (i=0; i<interp_elf_ex->e_phnum; i++, eppnt++) {
+ if (eppnt->p_type == PT_LOAD) {
+ int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
+ int elf_prot = 0;
+ unsigned long vaddr = 0;
+ unsigned long k, map_addr;
+
+ if (eppnt->p_flags & PF_R) elf_prot = PROT_READ;
+ if (eppnt->p_flags & PF_W) elf_prot |= PROT_WRITE;
+ if (eppnt->p_flags & PF_X) elf_prot |= PROT_EXEC;
+ vaddr = eppnt->p_vaddr;
+ if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
+ elf_type |= MAP_FIXED;
+
+ map_addr = elf_map(interpreter, load_addr + vaddr, eppnt, elf_prot, elf_type);
+ error = map_addr;
+ if (BAD_ADDR(map_addr))
+ goto out_close;
+
+ if (!load_addr_set && interp_elf_ex->e_type == ET_DYN) {
+ load_addr = map_addr - ELF_PAGESTART(vaddr);
+ load_addr_set = 1;
+ }
+
+ /*
+ * Check to see if the section's size will overflow the
+ * allowed task size. Note that p_filesz must always be
+ * <= p_memsize so it is only necessary to check p_memsz.
+ */
+ k = load_addr + eppnt->p_vaddr;
+ if (k > TASK_SIZE || eppnt->p_filesz > eppnt->p_memsz ||
+ eppnt->p_memsz > TASK_SIZE || TASK_SIZE - eppnt->p_memsz < k) {
+ error = -ENOMEM;
+ goto out_close;
+ }
+
+ /*
+ * Find the end of the file mapping for this phdr, and keep
+ * track of the largest address we see for this.
+ */
+ k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
+ if (k > elf_bss)
+ elf_bss = k;
+
+ /*
+ * Do the same thing for the memory mapping - between
+ * elf_bss and last_bss is the bss section.
+ */
+ k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
+ if (k > last_bss)
+ last_bss = k;
+ }
+ }
+
+ /*
+ * Now fill out the bss section. First pad the last page up
+ * to the page boundary, and then perform a mmap to make sure
+ * that there are zero-mapped pages up to and including the
+ * last bss page.
+ */
+ if (padzero(elf_bss)) {
+ error = -EFAULT;
+ goto out_close;
+ }
+
+ elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1); /* What we have mapped so far */
+
+ /* Map the last of the bss segment */
+ if (last_bss > elf_bss) {
+ down_write(&current->mm->mmap_sem);
+ error = do_brk(elf_bss, last_bss - elf_bss);
+ up_write(&current->mm->mmap_sem);
+ if (BAD_ADDR(error))
+ goto out_close;
+ }
+
+ *interp_load_addr = load_addr;
+ error = ((unsigned long) interp_elf_ex->e_entry) + load_addr;
+
+out_close:
+ kfree(elf_phdata);
+out:
+ return error;
+}
+
+static unsigned long load_aout_interp(struct exec * interp_ex,
+ struct file * interpreter)
+{
+ unsigned long text_data, elf_entry = ~0UL;
+ char __user * addr;
+ loff_t offset;
+
+ current->mm->end_code = interp_ex->a_text;
+ text_data = interp_ex->a_text + interp_ex->a_data;
+ current->mm->end_data = text_data;
+ current->mm->brk = interp_ex->a_bss + text_data;
+
+ switch (N_MAGIC(*interp_ex)) {
+ case OMAGIC:
+ offset = 32;
+ addr = (char __user *)0;
+ break;
+ case ZMAGIC:
+ case QMAGIC:
+ offset = N_TXTOFF(*interp_ex);
+ addr = (char __user *) N_TXTADDR(*interp_ex);
+ break;
+ default:
+ goto out;
+ }
+
+ down_write(&current->mm->mmap_sem);
+ do_brk(0, text_data);
+ up_write(&current->mm->mmap_sem);
+ if (!interpreter->f_op || !interpreter->f_op->read)
+ goto out;
+ if (interpreter->f_op->read(interpreter, addr, text_data, &offset) < 0)
+ goto out;
+ flush_icache_range((unsigned long)addr,
+ (unsigned long)addr + text_data);
+
+
+ down_write(&current->mm->mmap_sem);
+ do_brk(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1),
+ interp_ex->a_bss);
+ up_write(&current->mm->mmap_sem);
+ elf_entry = interp_ex->a_entry;
+
+out:
+ return elf_entry;
+}
+
+/*
+ * These are the functions used to load ELF style executables and shared
+ * libraries. There is no binary dependent code anywhere else.
+ */
+
+#define INTERPRETER_NONE 0
+#define INTERPRETER_AOUT 1
+#define INTERPRETER_ELF 2
+
+
+static unsigned long randomize_stack_top(unsigned long stack_top)
+{
+ unsigned int random_variable = 0;
+
+ if (current->flags & PF_RANDOMIZE)
+ random_variable = get_random_int() % (8*1024*1024);
+#ifdef CONFIG_STACK_GROWSUP
+ return PAGE_ALIGN(stack_top + random_variable);
+#else
+ return PAGE_ALIGN(stack_top - random_variable);
+#endif
+}
+
+static int load_elf_binary(struct linux_binprm * bprm, struct pt_regs * regs)
+{
+ struct file *interpreter = NULL; /* to shut gcc up */
+ unsigned long load_addr = 0, load_bias = 0;
+ int load_addr_set = 0;
+ char * elf_interpreter = NULL;
+ unsigned int interpreter_type = INTERPRETER_NONE;
+ unsigned char ibcs2_interpreter = 0;
+ unsigned long error;
+ struct elf_phdr * elf_ppnt, *elf_phdata;
+ unsigned long elf_bss, elf_brk;
+ int elf_exec_fileno;
+ int retval, i;
+ unsigned int size;
+ unsigned long elf_entry, interp_load_addr = 0;
+ unsigned long start_code, end_code, start_data, end_data;
+ unsigned long reloc_func_desc = 0;
+ char passed_fileno[6];
+ struct files_struct *files;
+ int have_pt_gnu_stack, executable_stack = EXSTACK_DEFAULT;
+ unsigned long def_flags = 0;
+ struct {
+ struct elfhdr elf_ex;
+ struct elfhdr interp_elf_ex;
+ struct exec interp_ex;
+ } *loc;
+
+ loc = kmalloc(sizeof(*loc), GFP_KERNEL);
+ if (!loc) {
+ retval = -ENOMEM;
+ goto out_ret;
+ }
+
+ /* Get the exec-header */
+ loc->elf_ex = *((struct elfhdr *) bprm->buf);
+
+ retval = -ENOEXEC;
+ /* First of all, some simple consistency checks */
+ if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
+ goto out;
+
+ if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
+ goto out;
+ if (!elf_check_arch(&loc->elf_ex))
+ goto out;
+ if (!bprm->file->f_op||!bprm->file->f_op->mmap)
+ goto out;
+
+ /* Now read in all of the header information */
+
+ if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
+ goto out;
+ if (loc->elf_ex.e_phnum < 1 ||
+ loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
+ goto out;
+ size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
+ retval = -ENOMEM;
+ elf_phdata = (struct elf_phdr *) kmalloc(size, GFP_KERNEL);
+ if (!elf_phdata)
+ goto out;
+
+ retval = kernel_read(bprm->file, loc->elf_ex.e_phoff, (char *) elf_phdata, size);
+ if (retval != size) {
+ if (retval >= 0)
+ retval = -EIO;
+ goto out_free_ph;
+ }
+
+ files = current->files; /* Refcounted so ok */
+ retval = unshare_files();
+ if (retval < 0)
+ goto out_free_ph;
+ if (files == current->files) {
+ put_files_struct(files);
+ files = NULL;
+ }
+
+ /* exec will make our files private anyway, but for the a.out
+ loader stuff we need to do it earlier */
+
+ retval = get_unused_fd();
+ if (retval < 0)
+ goto out_free_fh;
+ get_file(bprm->file);
+ fd_install(elf_exec_fileno = retval, bprm->file);
+
+ elf_ppnt = elf_phdata;
+ elf_bss = 0;
+ elf_brk = 0;
+
+ start_code = ~0UL;
+ end_code = 0;
+ start_data = 0;
+ end_data = 0;
+
+ for (i = 0; i < loc->elf_ex.e_phnum; i++) {
+ if (elf_ppnt->p_type == PT_INTERP) {
+ /* This is the program interpreter used for
+ * shared libraries - for now assume that this
+ * is an a.out format binary
+ */
+
+ retval = -ENOEXEC;
+ if (elf_ppnt->p_filesz > PATH_MAX ||
+ elf_ppnt->p_filesz < 2)
+ goto out_free_file;
+
+ retval = -ENOMEM;
+ elf_interpreter = (char *) kmalloc(elf_ppnt->p_filesz,
+ GFP_KERNEL);
+ if (!elf_interpreter)
+ goto out_free_file;
+
+ retval = kernel_read(bprm->file, elf_ppnt->p_offset,
+ elf_interpreter,
+ elf_ppnt->p_filesz);
+ if (retval != elf_ppnt->p_filesz) {
+ if (retval >= 0)
+ retval = -EIO;
+ goto out_free_interp;
+ }
+ /* make sure path is NULL terminated */
+ retval = -ENOEXEC;
+ if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
+ goto out_free_interp;
+
+ /* If the program interpreter is one of these two,
+ * then assume an iBCS2 image. Otherwise assume
+ * a native linux image.
+ */
+ if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
+ strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0)
+ ibcs2_interpreter = 1;
+
+ /*
+ * The early SET_PERSONALITY here is so that the lookup
+ * for the interpreter happens in the namespace of the
+ * to-be-execed image. SET_PERSONALITY can select an
+ * alternate root.
+ *
+ * However, SET_PERSONALITY is NOT allowed to switch
+ * this task into the new images's memory mapping
+ * policy - that is, TASK_SIZE must still evaluate to
+ * that which is appropriate to the execing application.
+ * This is because exit_mmap() needs to have TASK_SIZE
+ * evaluate to the size of the old image.
+ *
+ * So if (say) a 64-bit application is execing a 32-bit
+ * application it is the architecture's responsibility
+ * to defer changing the value of TASK_SIZE until the
+ * switch really is going to happen - do this in
+ * flush_thread(). - akpm
+ */
+ SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
+
+ interpreter = open_exec(elf_interpreter);
+ retval = PTR_ERR(interpreter);
+ if (IS_ERR(interpreter))
+ goto out_free_interp;
+ retval = kernel_read(interpreter, 0, bprm->buf, BINPRM_BUF_SIZE);
+ if (retval != BINPRM_BUF_SIZE) {
+ if (retval >= 0)
+ retval = -EIO;
+ goto out_free_dentry;
+ }
+
+ /* Get the exec headers */
+ loc->interp_ex = *((struct exec *) bprm->buf);
+ loc->interp_elf_ex = *((struct elfhdr *) bprm->buf);
+ break;
+ }
+ elf_ppnt++;
+ }
+
+ elf_ppnt = elf_phdata;
+ for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
+ if (elf_ppnt->p_type == PT_GNU_STACK) {
+ if (elf_ppnt->p_flags & PF_X)
+ executable_stack = EXSTACK_ENABLE_X;
+ else
+ executable_stack = EXSTACK_DISABLE_X;
+ break;
+ }
+ have_pt_gnu_stack = (i < loc->elf_ex.e_phnum);
+
+ /* Some simple consistency checks for the interpreter */
+ if (elf_interpreter) {
+ interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
+
+ /* Now figure out which format our binary is */
+ if ((N_MAGIC(loc->interp_ex) != OMAGIC) &&
+ (N_MAGIC(loc->interp_ex) != ZMAGIC) &&
+ (N_MAGIC(loc->interp_ex) != QMAGIC))
+ interpreter_type = INTERPRETER_ELF;
+
+ if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
+ interpreter_type &= ~INTERPRETER_ELF;
+
+ retval = -ELIBBAD;
+ if (!interpreter_type)
+ goto out_free_dentry;
+
+ /* Make sure only one type was selected */
+ if ((interpreter_type & INTERPRETER_ELF) &&
+ interpreter_type != INTERPRETER_ELF) {
+ // FIXME - ratelimit this before re-enabling
+ // printk(KERN_WARNING "ELF: Ambiguous type, using ELF\n");
+ interpreter_type = INTERPRETER_ELF;
+ }
+ /* Verify the interpreter has a valid arch */
+ if ((interpreter_type == INTERPRETER_ELF) &&
+ !elf_check_arch(&loc->interp_elf_ex))
+ goto out_free_dentry;
+ } else {
+ /* Executables without an interpreter also need a personality */
+ SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
+ }
+
+ /* OK, we are done with that, now set up the arg stuff,
+ and then start this sucker up */
+
+ if ((!bprm->sh_bang) && (interpreter_type == INTERPRETER_AOUT)) {
+ char *passed_p = passed_fileno;
+ sprintf(passed_fileno, "%d", elf_exec_fileno);
+
+ if (elf_interpreter) {
+ retval = copy_strings_kernel(1, &passed_p, bprm);
+ if (retval)
+ goto out_free_dentry;
+ bprm->argc++;
+ }
+ }
+
+ /* Flush all traces of the currently running executable */
+ retval = flush_old_exec(bprm);
+ if (retval)
+ goto out_free_dentry;
+
+ /* Discard our unneeded old files struct */
+ if (files) {
+ steal_locks(files);
+ put_files_struct(files);
+ files = NULL;
+ }
+
+ /* OK, This is the point of no return */
+ current->mm->start_data = 0;
+ current->mm->end_data = 0;
+ current->mm->end_code = 0;
+ current->mm->mmap = NULL;
+ current->flags &= ~PF_FORKNOEXEC;
+ current->mm->def_flags = def_flags;
+
+ /* Do this immediately, since STACK_TOP as used in setup_arg_pages
+ may depend on the personality. */
+ SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
+ if (elf_read_implies_exec(loc->elf_ex, executable_stack))
+ current->personality |= READ_IMPLIES_EXEC;
+
+ if ( !(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
+ current->flags |= PF_RANDOMIZE;
+ arch_pick_mmap_layout(current->mm);
+
+ /* Do this so that we can load the interpreter, if need be. We will
+ change some of these later */
+ set_mm_counter(current->mm, rss, 0);
+ current->mm->free_area_cache = current->mm->mmap_base;
+ retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
+ executable_stack);
+ if (retval < 0) {
+ send_sig(SIGKILL, current, 0);
+ goto out_free_dentry;
+ }
+
+#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
+ retval = arch_setup_additional_pages(bprm, executable_stack);
+ if (retval < 0) {
+ send_sig(SIGKILL, current, 0);
+ goto out_free_dentry;
+ }
+#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
+
+ current->mm->start_stack = bprm->p;
+
+ /* Now we do a little grungy work by mmaping the ELF image into
+ the correct location in memory. At this point, we assume that
+ the image should be loaded at fixed address, not at a variable
+ address. */
+
+ for(i = 0, elf_ppnt = elf_phdata; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
+ int elf_prot = 0, elf_flags;
+ unsigned long k, vaddr;
+
+ if (elf_ppnt->p_type != PT_LOAD)
+ continue;
+
+ if (unlikely (elf_brk > elf_bss)) {
+ unsigned long nbyte;
+
+ /* There was a PT_LOAD segment with p_memsz > p_filesz
+ before this one. Map anonymous pages, if needed,
+ and clear the area. */
+ retval = set_brk (elf_bss + load_bias,
+ elf_brk + load_bias);
+ if (retval) {
+ send_sig(SIGKILL, current, 0);
+ goto out_free_dentry;
+ }
+ nbyte = ELF_PAGEOFFSET(elf_bss);
+ if (nbyte) {
+ nbyte = ELF_MIN_ALIGN - nbyte;
+ if (nbyte > elf_brk - elf_bss)
+ nbyte = elf_brk - elf_bss;
+ if (clear_user((void __user *)elf_bss +
+ load_bias, nbyte)) {
+ /*
+ * This bss-zeroing can fail if the ELF
+ * file specifies odd protections. So
+ * we don't check the return value
+ */
+ }
+ }
+ }
+
+ if (elf_ppnt->p_flags & PF_R) elf_prot |= PROT_READ;
+ if (elf_ppnt->p_flags & PF_W) elf_prot |= PROT_WRITE;
+ if (elf_ppnt->p_flags & PF_X) elf_prot |= PROT_EXEC;
+
+ elf_flags = MAP_PRIVATE|MAP_DENYWRITE|MAP_EXECUTABLE;
+
+ vaddr = elf_ppnt->p_vaddr;
+ if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
+ elf_flags |= MAP_FIXED;
+ } else if (loc->elf_ex.e_type == ET_DYN) {
+ /* Try and get dynamic programs out of the way of the default mmap
+ base, as well as whatever program they might try to exec. This
+ is because the brk will follow the loader, and is not movable. */
+ load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
+ }
+
+ error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, elf_prot, elf_flags);
+ if (BAD_ADDR(error)) {
+ send_sig(SIGKILL, current, 0);
+ goto out_free_dentry;
+ }
+
+ if (!load_addr_set) {
+ load_addr_set = 1;
+ load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
+ if (loc->elf_ex.e_type == ET_DYN) {
+ load_bias += error -
+ ELF_PAGESTART(load_bias + vaddr);
+ load_addr += load_bias;
+ reloc_func_desc = load_bias;
+ }
+ }
+ k = elf_ppnt->p_vaddr;
+ if (k < start_code) start_code = k;
+ if (start_data < k) start_data = k;
+
+ /*
+ * Check to see if the section's size will overflow the
+ * allowed task size. Note that p_filesz must always be
+ * <= p_memsz so it is only necessary to check p_memsz.
+ */
+ if (k > TASK_SIZE || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
+ elf_ppnt->p_memsz > TASK_SIZE ||
+ TASK_SIZE - elf_ppnt->p_memsz < k) {
+ /* set_brk can never work. Avoid overflows. */
+ send_sig(SIGKILL, current, 0);
+ goto out_free_dentry;
+ }
+
+ k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
+
+ if (k > elf_bss)
+ elf_bss = k;
+ if ((elf_ppnt->p_flags & PF_X) && end_code < k)
+ end_code = k;
+ if (end_data < k)
+ end_data = k;
+ k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
+ if (k > elf_brk)
+ elf_brk = k;
+ }
+
+ loc->elf_ex.e_entry += load_bias;
+ elf_bss += load_bias;
+ elf_brk += load_bias;
+ start_code += load_bias;
+ end_code += load_bias;
+ start_data += load_bias;
+ end_data += load_bias;
+
+ /* Calling set_brk effectively mmaps the pages that we need
+ * for the bss and break sections. We must do this before
+ * mapping in the interpreter, to make sure it doesn't wind
+ * up getting placed where the bss needs to go.
+ */
+ retval = set_brk(elf_bss, elf_brk);
+ if (retval) {
+ send_sig(SIGKILL, current, 0);
+ goto out_free_dentry;
+ }
+ if (padzero(elf_bss)) {
+ send_sig(SIGSEGV, current, 0);
+ retval = -EFAULT; /* Nobody gets to see this, but.. */
+ goto out_free_dentry;
+ }
+
+ if (elf_interpreter) {
+ if (interpreter_type == INTERPRETER_AOUT)
+ elf_entry = load_aout_interp(&loc->interp_ex,
+ interpreter);
+ else
+ elf_entry = load_elf_interp(&loc->interp_elf_ex,
+ interpreter,
+ &interp_load_addr);
+ if (BAD_ADDR(elf_entry)) {
+ printk(KERN_ERR "Unable to load interpreter %.128s\n",
+ elf_interpreter);
+ force_sig(SIGSEGV, current);
+ retval = -ENOEXEC; /* Nobody gets to see this, but.. */
+ goto out_free_dentry;
+ }
+ reloc_func_desc = interp_load_addr;
+
+ allow_write_access(interpreter);
+ fput(interpreter);
+ kfree(elf_interpreter);
+ } else {
+ elf_entry = loc->elf_ex.e_entry;
+ }
+
+ kfree(elf_phdata);
+
+ if (interpreter_type != INTERPRETER_AOUT)
+ sys_close(elf_exec_fileno);
+
+ set_binfmt(&elf_format);
+
+ compute_creds(bprm);
+ current->flags &= ~PF_FORKNOEXEC;
+ create_elf_tables(bprm, &loc->elf_ex, (interpreter_type == INTERPRETER_AOUT),
+ load_addr, interp_load_addr);
+ /* N.B. passed_fileno might not be initialized? */
+ if (interpreter_type == INTERPRETER_AOUT)
+ current->mm->arg_start += strlen(passed_fileno) + 1;
+ current->mm->end_code = end_code;
+ current->mm->start_code = start_code;
+ current->mm->start_data = start_data;
+ current->mm->end_data = end_data;
+ current->mm->start_stack = bprm->p;
+
+ if (current->personality & MMAP_PAGE_ZERO) {
+ /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
+ and some applications "depend" upon this behavior.
+ Since we do not have the power to recompile these, we
+ emulate the SVr4 behavior. Sigh. */
+ down_write(&current->mm->mmap_sem);
+ error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
+ MAP_FIXED | MAP_PRIVATE, 0);
+ up_write(&current->mm->mmap_sem);
+ }
+
+#ifdef ELF_PLAT_INIT
+ /*
+ * The ABI may specify that certain registers be set up in special
+ * ways (on i386 %edx is the address of a DT_FINI function, for
+ * example. In addition, it may also specify (eg, PowerPC64 ELF)
+ * that the e_entry field is the address of the function descriptor
+ * for the startup routine, rather than the address of the startup
+ * routine itself. This macro performs whatever initialization to
+ * the regs structure is required as well as any relocations to the
+ * function descriptor entries when executing dynamically links apps.
+ */
+ ELF_PLAT_INIT(regs, reloc_func_desc);
+#endif
+
+ start_thread(regs, elf_entry, bprm->p);
+ if (unlikely(current->ptrace & PT_PTRACED)) {
+ if (current->ptrace & PT_TRACE_EXEC)
+ ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
+ else
+ send_sig(SIGTRAP, current, 0);
+ }
+ retval = 0;
+out:
+ kfree(loc);
+out_ret:
+ return retval;
+
+ /* error cleanup */
+out_free_dentry:
+ allow_write_access(interpreter);
+ if (interpreter)
+ fput(interpreter);
+out_free_interp:
+ if (elf_interpreter)
+ kfree(elf_interpreter);
+out_free_file:
+ sys_close(elf_exec_fileno);
+out_free_fh:
+ if (files) {
+ put_files_struct(current->files);
+ current->files = files;
+ }
+out_free_ph:
+ kfree(elf_phdata);
+ goto out;
+}
+
+/* This is really simpleminded and specialized - we are loading an
+ a.out library that is given an ELF header. */
+
+static int load_elf_library(struct file *file)
+{
+ struct elf_phdr *elf_phdata;
+ struct elf_phdr *eppnt;
+ unsigned long elf_bss, bss, len;
+ int retval, error, i, j;
+ struct elfhdr elf_ex;
+
+ error = -ENOEXEC;
+ retval = kernel_read(file, 0, (char *) &elf_ex, sizeof(elf_ex));
+ if (retval != sizeof(elf_ex))
+ goto out;
+
+ if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
+ goto out;
+
+ /* First of all, some simple consistency checks */
+ if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
+ !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
+ goto out;
+
+ /* Now read in all of the header information */
+
+ j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
+ /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
+
+ error = -ENOMEM;
+ elf_phdata = kmalloc(j, GFP_KERNEL);
+ if (!elf_phdata)
+ goto out;
+
+ eppnt = elf_phdata;
+ error = -ENOEXEC;
+ retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
+ if (retval != j)
+ goto out_free_ph;
+
+ for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
+ if ((eppnt + i)->p_type == PT_LOAD)
+ j++;
+ if (j != 1)
+ goto out_free_ph;
+
+ while (eppnt->p_type != PT_LOAD)
+ eppnt++;
+
+ /* Now use mmap to map the library into memory. */
+ down_write(&current->mm->mmap_sem);
+ error = do_mmap(file,
+ ELF_PAGESTART(eppnt->p_vaddr),
+ (eppnt->p_filesz +
+ ELF_PAGEOFFSET(eppnt->p_vaddr)),
+ PROT_READ | PROT_WRITE | PROT_EXEC,
+ MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
+ (eppnt->p_offset -
+ ELF_PAGEOFFSET(eppnt->p_vaddr)));
+ up_write(&current->mm->mmap_sem);
+ if (error != ELF_PAGESTART(eppnt->p_vaddr))
+ goto out_free_ph;
+
+ elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
+ if (padzero(elf_bss)) {
+ error = -EFAULT;
+ goto out_free_ph;
+ }
+
+ len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + ELF_MIN_ALIGN - 1);
+ bss = eppnt->p_memsz + eppnt->p_vaddr;
+ if (bss > len) {
+ down_write(&current->mm->mmap_sem);
+ do_brk(len, bss - len);
+ up_write(&current->mm->mmap_sem);
+ }
+ error = 0;
+
+out_free_ph:
+ kfree(elf_phdata);
+out:
+ return error;
+}
+
+/*
+ * Note that some platforms still use traditional core dumps and not
+ * the ELF core dump. Each platform can select it as appropriate.
+ */
+#ifdef USE_ELF_CORE_DUMP