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!
diff --git a/fs/exec.c b/fs/exec.c
new file mode 100644
index 0000000..a839449
--- /dev/null
+++ b/fs/exec.c
@@ -0,0 +1,1498 @@
+/*
+ * linux/fs/exec.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ */
+
+/*
+ * #!-checking implemented by tytso.
+ */
+/*
+ * Demand-loading implemented 01.12.91 - no need to read anything but
+ * the header into memory. The inode of the executable is put into
+ * "current->executable", and page faults do the actual loading. Clean.
+ *
+ * Once more I can proudly say that linux stood up to being changed: it
+ * was less than 2 hours work to get demand-loading completely implemented.
+ *
+ * Demand loading changed July 1993 by Eric Youngdale. Use mmap instead,
+ * current->executable is only used by the procfs. This allows a dispatch
+ * table to check for several different types of binary formats. We keep
+ * trying until we recognize the file or we run out of supported binary
+ * formats.
+ */
+
+#include <linux/config.h>
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/mman.h>
+#include <linux/a.out.h>
+#include <linux/stat.h>
+#include <linux/fcntl.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/spinlock.h>
+#include <linux/key.h>
+#include <linux/personality.h>
+#include <linux/binfmts.h>
+#include <linux/swap.h>
+#include <linux/utsname.h>
+#include <linux/module.h>
+#include <linux/namei.h>
+#include <linux/proc_fs.h>
+#include <linux/ptrace.h>
+#include <linux/mount.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/rmap.h>
+#include <linux/acct.h>
+
+#include <asm/uaccess.h>
+#include <asm/mmu_context.h>
+
+#ifdef CONFIG_KMOD
+#include <linux/kmod.h>
+#endif
+
+int core_uses_pid;
+char core_pattern[65] = "core";
+/* The maximal length of core_pattern is also specified in sysctl.c */
+
+static struct linux_binfmt *formats;
+static DEFINE_RWLOCK(binfmt_lock);
+
+int register_binfmt(struct linux_binfmt * fmt)
+{
+ struct linux_binfmt ** tmp = &formats;
+
+ if (!fmt)
+ return -EINVAL;
+ if (fmt->next)
+ return -EBUSY;
+ write_lock(&binfmt_lock);
+ while (*tmp) {
+ if (fmt == *tmp) {
+ write_unlock(&binfmt_lock);
+ return -EBUSY;
+ }
+ tmp = &(*tmp)->next;
+ }
+ fmt->next = formats;
+ formats = fmt;
+ write_unlock(&binfmt_lock);
+ return 0;
+}
+
+EXPORT_SYMBOL(register_binfmt);
+
+int unregister_binfmt(struct linux_binfmt * fmt)
+{
+ struct linux_binfmt ** tmp = &formats;
+
+ write_lock(&binfmt_lock);
+ while (*tmp) {
+ if (fmt == *tmp) {
+ *tmp = fmt->next;
+ write_unlock(&binfmt_lock);
+ return 0;
+ }
+ tmp = &(*tmp)->next;
+ }
+ write_unlock(&binfmt_lock);
+ return -EINVAL;
+}
+
+EXPORT_SYMBOL(unregister_binfmt);
+
+static inline void put_binfmt(struct linux_binfmt * fmt)
+{
+ module_put(fmt->module);
+}
+
+/*
+ * Note that a shared library must be both readable and executable due to
+ * security reasons.
+ *
+ * Also note that we take the address to load from from the file itself.
+ */
+asmlinkage long sys_uselib(const char __user * library)
+{
+ struct file * file;
+ struct nameidata nd;
+ int error;
+
+ nd.intent.open.flags = FMODE_READ;
+ error = __user_walk(library, LOOKUP_FOLLOW|LOOKUP_OPEN, &nd);
+ if (error)
+ goto out;
+
+ error = -EINVAL;
+ if (!S_ISREG(nd.dentry->d_inode->i_mode))
+ goto exit;
+
+ error = permission(nd.dentry->d_inode, MAY_READ | MAY_EXEC, &nd);
+ if (error)
+ goto exit;
+
+ file = dentry_open(nd.dentry, nd.mnt, O_RDONLY);
+ error = PTR_ERR(file);
+ if (IS_ERR(file))
+ goto out;
+
+ error = -ENOEXEC;
+ if(file->f_op) {
+ struct linux_binfmt * fmt;
+
+ read_lock(&binfmt_lock);
+ for (fmt = formats ; fmt ; fmt = fmt->next) {
+ if (!fmt->load_shlib)
+ continue;
+ if (!try_module_get(fmt->module))
+ continue;
+ read_unlock(&binfmt_lock);
+ error = fmt->load_shlib(file);
+ read_lock(&binfmt_lock);
+ put_binfmt(fmt);
+ if (error != -ENOEXEC)
+ break;
+ }
+ read_unlock(&binfmt_lock);
+ }
+ fput(file);
+out:
+ return error;
+exit:
+ path_release(&nd);
+ goto out;
+}
+
+/*
+ * count() counts the number of strings in array ARGV.
+ */
+static int count(char __user * __user * argv, int max)
+{
+ int i = 0;
+
+ if (argv != NULL) {
+ for (;;) {
+ char __user * p;
+
+ if (get_user(p, argv))
+ return -EFAULT;
+ if (!p)
+ break;
+ argv++;
+ if(++i > max)
+ return -E2BIG;
+ cond_resched();
+ }
+ }
+ return i;
+}
+
+/*
+ * 'copy_strings()' copies argument/environment strings from user
+ * memory to free pages in kernel mem. These are in a format ready
+ * to be put directly into the top of new user memory.
+ */
+int copy_strings(int argc,char __user * __user * argv, struct linux_binprm *bprm)
+{
+ struct page *kmapped_page = NULL;
+ char *kaddr = NULL;
+ int ret;
+
+ while (argc-- > 0) {
+ char __user *str;
+ int len;
+ unsigned long pos;
+
+ if (get_user(str, argv+argc) ||
+ !(len = strnlen_user(str, bprm->p))) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ if (bprm->p < len) {
+ ret = -E2BIG;
+ goto out;
+ }
+
+ bprm->p -= len;
+ /* XXX: add architecture specific overflow check here. */
+ pos = bprm->p;
+
+ while (len > 0) {
+ int i, new, err;
+ int offset, bytes_to_copy;
+ struct page *page;
+
+ offset = pos % PAGE_SIZE;
+ i = pos/PAGE_SIZE;
+ page = bprm->page[i];
+ new = 0;
+ if (!page) {
+ page = alloc_page(GFP_HIGHUSER);
+ bprm->page[i] = page;
+ if (!page) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ new = 1;
+ }
+
+ if (page != kmapped_page) {
+ if (kmapped_page)
+ kunmap(kmapped_page);
+ kmapped_page = page;
+ kaddr = kmap(kmapped_page);
+ }
+ if (new && offset)
+ memset(kaddr, 0, offset);
+ bytes_to_copy = PAGE_SIZE - offset;
+ if (bytes_to_copy > len) {
+ bytes_to_copy = len;
+ if (new)
+ memset(kaddr+offset+len, 0,
+ PAGE_SIZE-offset-len);
+ }
+ err = copy_from_user(kaddr+offset, str, bytes_to_copy);
+ if (err) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ pos += bytes_to_copy;
+ str += bytes_to_copy;
+ len -= bytes_to_copy;
+ }
+ }
+ ret = 0;
+out:
+ if (kmapped_page)
+ kunmap(kmapped_page);
+ return ret;
+}
+
+/*
+ * Like copy_strings, but get argv and its values from kernel memory.
+ */
+int copy_strings_kernel(int argc,char ** argv, struct linux_binprm *bprm)
+{
+ int r;
+ mm_segment_t oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ r = copy_strings(argc, (char __user * __user *)argv, bprm);
+ set_fs(oldfs);
+ return r;
+}
+
+EXPORT_SYMBOL(copy_strings_kernel);
+
+#ifdef CONFIG_MMU
+/*
+ * This routine is used to map in a page into an address space: needed by
+ * execve() for the initial stack and environment pages.
+ *
+ * vma->vm_mm->mmap_sem is held for writing.
+ */
+void install_arg_page(struct vm_area_struct *vma,
+ struct page *page, unsigned long address)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ pgd_t * pgd;
+ pud_t * pud;
+ pmd_t * pmd;
+ pte_t * pte;
+
+ if (unlikely(anon_vma_prepare(vma)))
+ goto out_sig;
+
+ flush_dcache_page(page);
+ pgd = pgd_offset(mm, address);
+
+ spin_lock(&mm->page_table_lock);
+ pud = pud_alloc(mm, pgd, address);
+ if (!pud)
+ goto out;
+ pmd = pmd_alloc(mm, pud, address);
+ if (!pmd)
+ goto out;
+ pte = pte_alloc_map(mm, pmd, address);
+ if (!pte)
+ goto out;
+ if (!pte_none(*pte)) {
+ pte_unmap(pte);
+ goto out;
+ }
+ inc_mm_counter(mm, rss);
+ lru_cache_add_active(page);
+ set_pte_at(mm, address, pte, pte_mkdirty(pte_mkwrite(mk_pte(
+ page, vma->vm_page_prot))));
+ page_add_anon_rmap(page, vma, address);
+ pte_unmap(pte);
+ spin_unlock(&mm->page_table_lock);
+
+ /* no need for flush_tlb */
+ return;
+out:
+ spin_unlock(&mm->page_table_lock);
+out_sig:
+ __free_page(page);
+ force_sig(SIGKILL, current);
+}
+
+#define EXTRA_STACK_VM_PAGES 20 /* random */
+
+int setup_arg_pages(struct linux_binprm *bprm,
+ unsigned long stack_top,
+ int executable_stack)
+{
+ unsigned long stack_base;
+ struct vm_area_struct *mpnt;
+ struct mm_struct *mm = current->mm;
+ int i, ret;
+ long arg_size;
+
+#ifdef CONFIG_STACK_GROWSUP
+ /* Move the argument and environment strings to the bottom of the
+ * stack space.
+ */
+ int offset, j;
+ char *to, *from;
+
+ /* Start by shifting all the pages down */
+ i = 0;
+ for (j = 0; j < MAX_ARG_PAGES; j++) {
+ struct page *page = bprm->page[j];
+ if (!page)
+ continue;
+ bprm->page[i++] = page;
+ }
+
+ /* Now move them within their pages */
+ offset = bprm->p % PAGE_SIZE;
+ to = kmap(bprm->page[0]);
+ for (j = 1; j < i; j++) {
+ memmove(to, to + offset, PAGE_SIZE - offset);
+ from = kmap(bprm->page[j]);
+ memcpy(to + PAGE_SIZE - offset, from, offset);
+ kunmap(bprm->page[j - 1]);
+ to = from;
+ }
+ memmove(to, to + offset, PAGE_SIZE - offset);
+ kunmap(bprm->page[j - 1]);
+
+ /* Limit stack size to 1GB */
+ stack_base = current->signal->rlim[RLIMIT_STACK].rlim_max;
+ if (stack_base > (1 << 30))
+ stack_base = 1 << 30;
+ stack_base = PAGE_ALIGN(stack_top - stack_base);
+
+ /* Adjust bprm->p to point to the end of the strings. */
+ bprm->p = stack_base + PAGE_SIZE * i - offset;
+
+ mm->arg_start = stack_base;
+ arg_size = i << PAGE_SHIFT;
+
+ /* zero pages that were copied above */
+ while (i < MAX_ARG_PAGES)
+ bprm->page[i++] = NULL;
+#else
+ stack_base = arch_align_stack(stack_top - MAX_ARG_PAGES*PAGE_SIZE);
+ stack_base = PAGE_ALIGN(stack_base);
+ bprm->p += stack_base;
+ mm->arg_start = bprm->p;
+ arg_size = stack_top - (PAGE_MASK & (unsigned long) mm->arg_start);
+#endif
+
+ arg_size += EXTRA_STACK_VM_PAGES * PAGE_SIZE;
+
+ if (bprm->loader)
+ bprm->loader += stack_base;
+ bprm->exec += stack_base;
+
+ mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
+ if (!mpnt)
+ return -ENOMEM;
+
+ if (security_vm_enough_memory(arg_size >> PAGE_SHIFT)) {
+ kmem_cache_free(vm_area_cachep, mpnt);
+ return -ENOMEM;
+ }
+
+ memset(mpnt, 0, sizeof(*mpnt));
+
+ down_write(&mm->mmap_sem);
+ {
+ mpnt->vm_mm = mm;
+#ifdef CONFIG_STACK_GROWSUP
+ mpnt->vm_start = stack_base;
+ mpnt->vm_end = stack_base + arg_size;
+#else
+ mpnt->vm_end = stack_top;
+ mpnt->vm_start = mpnt->vm_end - arg_size;
+#endif
+ /* Adjust stack execute permissions; explicitly enable
+ * for EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X
+ * and leave alone (arch default) otherwise. */
+ if (unlikely(executable_stack == EXSTACK_ENABLE_X))
+ mpnt->vm_flags = VM_STACK_FLAGS | VM_EXEC;
+ else if (executable_stack == EXSTACK_DISABLE_X)
+ mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC;
+ else
+ mpnt->vm_flags = VM_STACK_FLAGS;
+ mpnt->vm_flags |= mm->def_flags;
+ mpnt->vm_page_prot = protection_map[mpnt->vm_flags & 0x7];
+ if ((ret = insert_vm_struct(mm, mpnt))) {
+ up_write(&mm->mmap_sem);
+ kmem_cache_free(vm_area_cachep, mpnt);
+ return ret;
+ }
+ mm->stack_vm = mm->total_vm = vma_pages(mpnt);
+ }
+
+ for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
+ struct page *page = bprm->page[i];
+ if (page) {
+ bprm->page[i] = NULL;
+ install_arg_page(mpnt, page, stack_base);
+ }
+ stack_base += PAGE_SIZE;
+ }
+ up_write(&mm->mmap_sem);
+
+ return 0;
+}
+
+EXPORT_SYMBOL(setup_arg_pages);
+
+#define free_arg_pages(bprm) do { } while (0)
+
+#else
+
+static inline void free_arg_pages(struct linux_binprm *bprm)
+{
+ int i;
+
+ for (i = 0; i < MAX_ARG_PAGES; i++) {
+ if (bprm->page[i])
+ __free_page(bprm->page[i]);
+ bprm->page[i] = NULL;
+ }
+}
+
+#endif /* CONFIG_MMU */
+
+struct file *open_exec(const char *name)
+{
+ struct nameidata nd;
+ int err;
+ struct file *file;
+
+ nd.intent.open.flags = FMODE_READ;
+ err = path_lookup(name, LOOKUP_FOLLOW|LOOKUP_OPEN, &nd);
+ file = ERR_PTR(err);
+
+ if (!err) {
+ struct inode *inode = nd.dentry->d_inode;
+ file = ERR_PTR(-EACCES);
+ if (!(nd.mnt->mnt_flags & MNT_NOEXEC) &&
+ S_ISREG(inode->i_mode)) {
+ int err = permission(inode, MAY_EXEC, &nd);
+ if (!err && !(inode->i_mode & 0111))
+ err = -EACCES;
+ file = ERR_PTR(err);
+ if (!err) {
+ file = dentry_open(nd.dentry, nd.mnt, O_RDONLY);
+ if (!IS_ERR(file)) {
+ err = deny_write_access(file);
+ if (err) {
+ fput(file);
+ file = ERR_PTR(err);
+ }
+ }
+out:
+ return file;
+ }
+ }
+ path_release(&nd);
+ }
+ goto out;
+}
+
+EXPORT_SYMBOL(open_exec);
+
+int kernel_read(struct file *file, unsigned long offset,
+ char *addr, unsigned long count)
+{
+ mm_segment_t old_fs;
+ loff_t pos = offset;
+ int result;
+
+ old_fs = get_fs();
+ set_fs(get_ds());
+ /* The cast to a user pointer is valid due to the set_fs() */
+ result = vfs_read(file, (void __user *)addr, count, &pos);
+ set_fs(old_fs);
+ return result;
+}
+
+EXPORT_SYMBOL(kernel_read);
+
+static int exec_mmap(struct mm_struct *mm)
+{
+ struct task_struct *tsk;
+ struct mm_struct * old_mm, *active_mm;
+
+ /* Notify parent that we're no longer interested in the old VM */
+ tsk = current;
+ old_mm = current->mm;
+ mm_release(tsk, old_mm);
+
+ if (old_mm) {
+ /*
+ * Make sure that if there is a core dump in progress
+ * for the old mm, we get out and die instead of going
+ * through with the exec. We must hold mmap_sem around
+ * checking core_waiters and changing tsk->mm. The
+ * core-inducing thread will increment core_waiters for
+ * each thread whose ->mm == old_mm.
+ */
+ down_read(&old_mm->mmap_sem);
+ if (unlikely(old_mm->core_waiters)) {
+ up_read(&old_mm->mmap_sem);
+ return -EINTR;
+ }
+ }
+ task_lock(tsk);
+ active_mm = tsk->active_mm;
+ tsk->mm = mm;
+ tsk->active_mm = mm;
+ activate_mm(active_mm, mm);
+ task_unlock(tsk);
+ arch_pick_mmap_layout(mm);
+ if (old_mm) {
+ up_read(&old_mm->mmap_sem);
+ if (active_mm != old_mm) BUG();
+ mmput(old_mm);
+ return 0;
+ }
+ mmdrop(active_mm);
+ return 0;
+}
+
+/*
+ * This function makes sure the current process has its own signal table,
+ * so that flush_signal_handlers can later reset the handlers without
+ * disturbing other processes. (Other processes might share the signal
+ * table via the CLONE_SIGHAND option to clone().)
+ */
+static inline int de_thread(struct task_struct *tsk)
+{
+ struct signal_struct *sig = tsk->signal;
+ struct sighand_struct *newsighand, *oldsighand = tsk->sighand;
+ spinlock_t *lock = &oldsighand->siglock;
+ int count;
+
+ /*
+ * If we don't share sighandlers, then we aren't sharing anything
+ * and we can just re-use it all.
+ */
+ if (atomic_read(&oldsighand->count) <= 1) {
+ BUG_ON(atomic_read(&sig->count) != 1);
+ exit_itimers(sig);
+ return 0;
+ }
+
+ newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
+ if (!newsighand)
+ return -ENOMEM;
+
+ if (thread_group_empty(current))
+ goto no_thread_group;
+
+ /*
+ * Kill all other threads in the thread group.
+ * We must hold tasklist_lock to call zap_other_threads.
+ */
+ read_lock(&tasklist_lock);
+ spin_lock_irq(lock);
+ if (sig->flags & SIGNAL_GROUP_EXIT) {
+ /*
+ * Another group action in progress, just
+ * return so that the signal is processed.
+ */
+ spin_unlock_irq(lock);
+ read_unlock(&tasklist_lock);
+ kmem_cache_free(sighand_cachep, newsighand);
+ return -EAGAIN;
+ }
+ zap_other_threads(current);
+ read_unlock(&tasklist_lock);
+
+ /*
+ * Account for the thread group leader hanging around:
+ */
+ count = 2;
+ if (thread_group_leader(current))
+ count = 1;
+ while (atomic_read(&sig->count) > count) {
+ sig->group_exit_task = current;
+ sig->notify_count = count;
+ __set_current_state(TASK_UNINTERRUPTIBLE);
+ spin_unlock_irq(lock);
+ schedule();
+ spin_lock_irq(lock);
+ }
+ sig->group_exit_task = NULL;
+ sig->notify_count = 0;
+ spin_unlock_irq(lock);
+
+ /*
+ * At this point all other threads have exited, all we have to
+ * do is to wait for the thread group leader to become inactive,
+ * and to assume its PID:
+ */
+ if (!thread_group_leader(current)) {
+ struct task_struct *leader = current->group_leader, *parent;
+ struct dentry *proc_dentry1, *proc_dentry2;
+ unsigned long exit_state, ptrace;
+
+ /*
+ * Wait for the thread group leader to be a zombie.
+ * It should already be zombie at this point, most
+ * of the time.
+ */
+ while (leader->exit_state != EXIT_ZOMBIE)
+ yield();
+
+ spin_lock(&leader->proc_lock);
+ spin_lock(¤t->proc_lock);
+ proc_dentry1 = proc_pid_unhash(current);
+ proc_dentry2 = proc_pid_unhash(leader);
+ write_lock_irq(&tasklist_lock);
+
+ if (leader->tgid != current->tgid)
+ BUG();
+ if (current->pid == current->tgid)
+ BUG();
+ /*
+ * An exec() starts a new thread group with the
+ * TGID of the previous thread group. Rehash the
+ * two threads with a switched PID, and release
+ * the former thread group leader:
+ */
+ ptrace = leader->ptrace;
+ parent = leader->parent;
+ if (unlikely(ptrace) && unlikely(parent == current)) {
+ /*
+ * Joker was ptracing his own group leader,
+ * and now he wants to be his own parent!
+ * We can't have that.
+ */
+ ptrace = 0;
+ }
+
+ ptrace_unlink(current);
+ ptrace_unlink(leader);
+ remove_parent(current);
+ remove_parent(leader);
+
+ switch_exec_pids(leader, current);
+
+ current->parent = current->real_parent = leader->real_parent;
+ leader->parent = leader->real_parent = child_reaper;
+ current->group_leader = current;
+ leader->group_leader = leader;
+
+ add_parent(current, current->parent);
+ add_parent(leader, leader->parent);
+ if (ptrace) {
+ current->ptrace = ptrace;
+ __ptrace_link(current, parent);
+ }
+
+ list_del(¤t->tasks);
+ list_add_tail(¤t->tasks, &init_task.tasks);
+ current->exit_signal = SIGCHLD;
+ exit_state = leader->exit_state;
+
+ write_unlock_irq(&tasklist_lock);
+ spin_unlock(&leader->proc_lock);
+ spin_unlock(¤t->proc_lock);
+ proc_pid_flush(proc_dentry1);
+ proc_pid_flush(proc_dentry2);
+
+ if (exit_state != EXIT_ZOMBIE)
+ BUG();
+ release_task(leader);
+ }
+
+ /*
+ * Now there are really no other threads at all,
+ * so it's safe to stop telling them to kill themselves.
+ */
+ sig->flags = 0;
+
+no_thread_group:
+ BUG_ON(atomic_read(&sig->count) != 1);
+ exit_itimers(sig);
+
+ if (atomic_read(&oldsighand->count) == 1) {
+ /*
+ * Now that we nuked the rest of the thread group,
+ * it turns out we are not sharing sighand any more either.
+ * So we can just keep it.
+ */
+ kmem_cache_free(sighand_cachep, newsighand);
+ } else {
+ /*
+ * Move our state over to newsighand and switch it in.
+ */
+ spin_lock_init(&newsighand->siglock);
+ atomic_set(&newsighand->count, 1);
+ memcpy(newsighand->action, oldsighand->action,
+ sizeof(newsighand->action));
+
+ write_lock_irq(&tasklist_lock);
+ spin_lock(&oldsighand->siglock);
+ spin_lock(&newsighand->siglock);
+
+ current->sighand = newsighand;
+ recalc_sigpending();
+
+ spin_unlock(&newsighand->siglock);
+ spin_unlock(&oldsighand->siglock);
+ write_unlock_irq(&tasklist_lock);
+
+ if (atomic_dec_and_test(&oldsighand->count))
+ kmem_cache_free(sighand_cachep, oldsighand);
+ }
+
+ if (!thread_group_empty(current))
+ BUG();
+ if (!thread_group_leader(current))
+ BUG();
+ return 0;
+}
+
+/*
+ * These functions flushes out all traces of the currently running executable
+ * so that a new one can be started
+ */
+
+static inline void flush_old_files(struct files_struct * files)
+{
+ long j = -1;
+
+ spin_lock(&files->file_lock);
+ for (;;) {
+ unsigned long set, i;
+
+ j++;
+ i = j * __NFDBITS;
+ if (i >= files->max_fds || i >= files->max_fdset)
+ break;
+ set = files->close_on_exec->fds_bits[j];
+ if (!set)
+ continue;
+ files->close_on_exec->fds_bits[j] = 0;
+ spin_unlock(&files->file_lock);
+ for ( ; set ; i++,set >>= 1) {
+ if (set & 1) {
+ sys_close(i);
+ }
+ }
+ spin_lock(&files->file_lock);
+
+ }
+ spin_unlock(&files->file_lock);
+}
+
+void get_task_comm(char *buf, struct task_struct *tsk)
+{
+ /* buf must be at least sizeof(tsk->comm) in size */
+ task_lock(tsk);
+ strncpy(buf, tsk->comm, sizeof(tsk->comm));
+ task_unlock(tsk);
+}
+
+void set_task_comm(struct task_struct *tsk, char *buf)
+{
+ task_lock(tsk);
+ strlcpy(tsk->comm, buf, sizeof(tsk->comm));
+ task_unlock(tsk);
+}
+
+int flush_old_exec(struct linux_binprm * bprm)
+{
+ char * name;
+ int i, ch, retval;
+ struct files_struct *files;
+ char tcomm[sizeof(current->comm)];
+
+ /*
+ * Make sure we have a private signal table and that
+ * we are unassociated from the previous thread group.
+ */
+ retval = de_thread(current);
+ if (retval)
+ goto out;
+
+ /*
+ * Make sure we have private file handles. Ask the
+ * fork helper to do the work for us and the exit
+ * helper to do the cleanup of the old one.
+ */
+ files = current->files; /* refcounted so safe to hold */
+ retval = unshare_files();
+ if (retval)
+ goto out;
+ /*
+ * Release all of the old mmap stuff
+ */
+ retval = exec_mmap(bprm->mm);
+ if (retval)
+ goto mmap_failed;
+
+ bprm->mm = NULL; /* We're using it now */
+
+ /* This is the point of no return */
+ steal_locks(files);
+ put_files_struct(files);
+
+ current->sas_ss_sp = current->sas_ss_size = 0;
+
+ if (current->euid == current->uid && current->egid == current->gid)
+ current->mm->dumpable = 1;
+ name = bprm->filename;
+ for (i=0; (ch = *(name++)) != '\0';) {
+ if (ch == '/')
+ i = 0;
+ else
+ if (i < (sizeof(tcomm) - 1))
+ tcomm[i++] = ch;
+ }
+ tcomm[i] = '\0';
+ set_task_comm(current, tcomm);
+
+ current->flags &= ~PF_RANDOMIZE;
+ flush_thread();
+
+ if (bprm->e_uid != current->euid || bprm->e_gid != current->egid ||
+ permission(bprm->file->f_dentry->d_inode,MAY_READ, NULL) ||
+ (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) {
+ suid_keys(current);
+ current->mm->dumpable = 0;
+ }
+
+ /* An exec changes our domain. We are no longer part of the thread
+ group */
+
+ current->self_exec_id++;
+
+ flush_signal_handlers(current, 0);
+ flush_old_files(current->files);
+
+ return 0;
+
+mmap_failed:
+ put_files_struct(current->files);
+ current->files = files;
+out:
+ return retval;
+}
+
+EXPORT_SYMBOL(flush_old_exec);
+
+/*
+ * Fill the binprm structure from the inode.
+ * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes
+ */
+int prepare_binprm(struct linux_binprm *bprm)
+{
+ int mode;
+ struct inode * inode = bprm->file->f_dentry->d_inode;
+ int retval;
+
+ mode = inode->i_mode;
+ /*
+ * Check execute perms again - if the caller has CAP_DAC_OVERRIDE,
+ * generic_permission lets a non-executable through
+ */
+ if (!(mode & 0111)) /* with at least _one_ execute bit set */
+ return -EACCES;
+ if (bprm->file->f_op == NULL)
+ return -EACCES;
+
+ bprm->e_uid = current->euid;
+ bprm->e_gid = current->egid;
+
+ if(!(bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)) {
+ /* Set-uid? */
+ if (mode & S_ISUID) {
+ current->personality &= ~PER_CLEAR_ON_SETID;
+ bprm->e_uid = inode->i_uid;
+ }
+
+ /* Set-gid? */
+ /*
+ * If setgid is set but no group execute bit then this
+ * is a candidate for mandatory locking, not a setgid
+ * executable.
+ */
+ if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
+ current->personality &= ~PER_CLEAR_ON_SETID;
+ bprm->e_gid = inode->i_gid;
+ }
+ }
+
+ /* fill in binprm security blob */
+ retval = security_bprm_set(bprm);
+ if (retval)
+ return retval;
+
+ memset(bprm->buf,0,BINPRM_BUF_SIZE);
+ return kernel_read(bprm->file,0,bprm->buf,BINPRM_BUF_SIZE);
+}
+
+EXPORT_SYMBOL(prepare_binprm);
+
+static inline int unsafe_exec(struct task_struct *p)
+{
+ int unsafe = 0;
+ if (p->ptrace & PT_PTRACED) {
+ if (p->ptrace & PT_PTRACE_CAP)
+ unsafe |= LSM_UNSAFE_PTRACE_CAP;
+ else
+ unsafe |= LSM_UNSAFE_PTRACE;
+ }
+ if (atomic_read(&p->fs->count) > 1 ||
+ atomic_read(&p->files->count) > 1 ||
+ atomic_read(&p->sighand->count) > 1)
+ unsafe |= LSM_UNSAFE_SHARE;
+
+ return unsafe;
+}
+
+void compute_creds(struct linux_binprm *bprm)
+{
+ int unsafe;
+
+ if (bprm->e_uid != current->uid)
+ suid_keys(current);
+ exec_keys(current);
+
+ task_lock(current);
+ unsafe = unsafe_exec(current);
+ security_bprm_apply_creds(bprm, unsafe);
+ task_unlock(current);
+ security_bprm_post_apply_creds(bprm);
+}
+
+EXPORT_SYMBOL(compute_creds);
+
+void remove_arg_zero(struct linux_binprm *bprm)
+{
+ if (bprm->argc) {
+ unsigned long offset;
+ char * kaddr;
+ struct page *page;
+
+ offset = bprm->p % PAGE_SIZE;
+ goto inside;
+
+ while (bprm->p++, *(kaddr+offset++)) {
+ if (offset != PAGE_SIZE)
+ continue;
+ offset = 0;
+ kunmap_atomic(kaddr, KM_USER0);
+inside:
+ page = bprm->page[bprm->p/PAGE_SIZE];
+ kaddr = kmap_atomic(page, KM_USER0);
+ }
+ kunmap_atomic(kaddr, KM_USER0);
+ bprm->argc--;
+ }
+}
+
+EXPORT_SYMBOL(remove_arg_zero);
+
+/*
+ * cycle the list of binary formats handler, until one recognizes the image
+ */
+int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
+{
+ int try,retval;
+ struct linux_binfmt *fmt;
+#ifdef __alpha__
+ /* handle /sbin/loader.. */
+ {
+ struct exec * eh = (struct exec *) bprm->buf;
+
+ if (!bprm->loader && eh->fh.f_magic == 0x183 &&
+ (eh->fh.f_flags & 0x3000) == 0x3000)
+ {
+ struct file * file;
+ unsigned long loader;
+
+ allow_write_access(bprm->file);
+ fput(bprm->file);
+ bprm->file = NULL;
+
+ loader = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *);
+
+ file = open_exec("/sbin/loader");
+ retval = PTR_ERR(file);
+ if (IS_ERR(file))
+ return retval;
+
+ /* Remember if the application is TASO. */
+ bprm->sh_bang = eh->ah.entry < 0x100000000UL;
+
+ bprm->file = file;
+ bprm->loader = loader;
+ retval = prepare_binprm(bprm);
+ if (retval<0)
+ return retval;
+ /* should call search_binary_handler recursively here,
+ but it does not matter */
+ }
+ }
+#endif
+ retval = security_bprm_check(bprm);
+ if (retval)
+ return retval;
+
+ /* kernel module loader fixup */
+ /* so we don't try to load run modprobe in kernel space. */
+ set_fs(USER_DS);
+ retval = -ENOENT;
+ for (try=0; try<2; try++) {
+ read_lock(&binfmt_lock);
+ for (fmt = formats ; fmt ; fmt = fmt->next) {
+ int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary;
+ if (!fn)
+ continue;
+ if (!try_module_get(fmt->module))
+ continue;
+ read_unlock(&binfmt_lock);
+ retval = fn(bprm, regs);
+ if (retval >= 0) {
+ put_binfmt(fmt);
+ allow_write_access(bprm->file);
+ if (bprm->file)
+ fput(bprm->file);
+ bprm->file = NULL;
+ current->did_exec = 1;
+ return retval;
+ }
+ read_lock(&binfmt_lock);
+ put_binfmt(fmt);
+ if (retval != -ENOEXEC || bprm->mm == NULL)
+ break;
+ if (!bprm->file) {
+ read_unlock(&binfmt_lock);
+ return retval;
+ }
+ }
+ read_unlock(&binfmt_lock);
+ if (retval != -ENOEXEC || bprm->mm == NULL) {
+ break;
+#ifdef CONFIG_KMOD
+ }else{
+#define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e))
+ if (printable(bprm->buf[0]) &&
+ printable(bprm->buf[1]) &&
+ printable(bprm->buf[2]) &&
+ printable(bprm->buf[3]))
+ break; /* -ENOEXEC */
+ request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2]));
+#endif
+ }
+ }
+ return retval;
+}
+
+EXPORT_SYMBOL(search_binary_handler);
+
+/*
+ * sys_execve() executes a new program.
+ */
+int do_execve(char * filename,
+ char __user *__user *argv,
+ char __user *__user *envp,
+ struct pt_regs * regs)
+{
+ struct linux_binprm *bprm;
+ struct file *file;
+ int retval;
+ int i;
+
+ retval = -ENOMEM;
+ bprm = kmalloc(sizeof(*bprm), GFP_KERNEL);
+ if (!bprm)
+ goto out_ret;
+ memset(bprm, 0, sizeof(*bprm));
+
+ file = open_exec(filename);
+ retval = PTR_ERR(file);
+ if (IS_ERR(file))
+ goto out_kfree;
+
+ sched_exec();
+
+ bprm->p = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *);
+
+ bprm->file = file;
+ bprm->filename = filename;
+ bprm->interp = filename;
+ bprm->mm = mm_alloc();
+ retval = -ENOMEM;
+ if (!bprm->mm)
+ goto out_file;
+
+ retval = init_new_context(current, bprm->mm);
+ if (retval < 0)
+ goto out_mm;
+
+ bprm->argc = count(argv, bprm->p / sizeof(void *));
+ if ((retval = bprm->argc) < 0)
+ goto out_mm;
+
+ bprm->envc = count(envp, bprm->p / sizeof(void *));
+ if ((retval = bprm->envc) < 0)
+ goto out_mm;
+
+ retval = security_bprm_alloc(bprm);
+ if (retval)
+ goto out;
+
+ retval = prepare_binprm(bprm);
+ if (retval < 0)
+ goto out;
+
+ retval = copy_strings_kernel(1, &bprm->filename, bprm);
+ if (retval < 0)
+ goto out;
+
+ bprm->exec = bprm->p;
+ retval = copy_strings(bprm->envc, envp, bprm);
+ if (retval < 0)
+ goto out;
+
+ retval = copy_strings(bprm->argc, argv, bprm);
+ if (retval < 0)
+ goto out;
+
+ retval = search_binary_handler(bprm,regs);
+ if (retval >= 0) {
+ free_arg_pages(bprm);
+
+ /* execve success */
+ security_bprm_free(bprm);
+ acct_update_integrals(current);
+ update_mem_hiwater(current);
+ kfree(bprm);
+ return retval;
+ }
+
+out:
+ /* Something went wrong, return the inode and free the argument pages*/
+ for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
+ struct page * page = bprm->page[i];
+ if (page)
+ __free_page(page);
+ }
+
+ if (bprm->security)
+ security_bprm_free(bprm);
+
+out_mm:
+ if (bprm->mm)
+ mmdrop(bprm->mm);
+
+out_file:
+ if (bprm->file) {
+ allow_write_access(bprm->file);
+ fput(bprm->file);
+ }
+
+out_kfree:
+ kfree(bprm);
+
+out_ret:
+ return retval;
+}
+
+int set_binfmt(struct linux_binfmt *new)
+{
+ struct linux_binfmt *old = current->binfmt;
+
+ if (new) {
+ if (!try_module_get(new->module))
+ return -1;
+ }
+ current->binfmt = new;
+ if (old)
+ module_put(old->module);
+ return 0;
+}
+
+EXPORT_SYMBOL(set_binfmt);
+
+#define CORENAME_MAX_SIZE 64
+
+/* format_corename will inspect the pattern parameter, and output a
+ * name into corename, which must have space for at least
+ * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator.
+ */
+static void format_corename(char *corename, const char *pattern, long signr)
+{
+ const char *pat_ptr = pattern;
+ char *out_ptr = corename;
+ char *const out_end = corename + CORENAME_MAX_SIZE;
+ int rc;
+ int pid_in_pattern = 0;
+
+ /* Repeat as long as we have more pattern to process and more output
+ space */
+ while (*pat_ptr) {
+ if (*pat_ptr != '%') {
+ if (out_ptr == out_end)
+ goto out;
+ *out_ptr++ = *pat_ptr++;
+ } else {
+ switch (*++pat_ptr) {
+ case 0:
+ goto out;
+ /* Double percent, output one percent */
+ case '%':
+ if (out_ptr == out_end)
+ goto out;
+ *out_ptr++ = '%';
+ break;
+ /* pid */
+ case 'p':
+ pid_in_pattern = 1;
+ rc = snprintf(out_ptr, out_end - out_ptr,
+ "%d", current->tgid);
+ if (rc > out_end - out_ptr)
+ goto out;
+ out_ptr += rc;
+ break;
+ /* uid */
+ case 'u':
+ rc = snprintf(out_ptr, out_end - out_ptr,
+ "%d", current->uid);
+ if (rc > out_end - out_ptr)
+ goto out;
+ out_ptr += rc;
+ break;
+ /* gid */
+ case 'g':
+ rc = snprintf(out_ptr, out_end - out_ptr,
+ "%d", current->gid);
+ if (rc > out_end - out_ptr)
+ goto out;
+ out_ptr += rc;
+ break;
+ /* signal that caused the coredump */
+ case 's':
+ rc = snprintf(out_ptr, out_end - out_ptr,
+ "%ld", signr);
+ if (rc > out_end - out_ptr)
+ goto out;
+ out_ptr += rc;
+ break;
+ /* UNIX time of coredump */
+ case 't': {
+ struct timeval tv;
+ do_gettimeofday(&tv);
+ rc = snprintf(out_ptr, out_end - out_ptr,
+ "%lu", tv.tv_sec);
+ if (rc > out_end - out_ptr)
+ goto out;
+ out_ptr += rc;
+ break;
+ }
+ /* hostname */
+ case 'h':
+ down_read(&uts_sem);
+ rc = snprintf(out_ptr, out_end - out_ptr,
+ "%s", system_utsname.nodename);
+ up_read(&uts_sem);
+ if (rc > out_end - out_ptr)
+ goto out;
+ out_ptr += rc;
+ break;
+ /* executable */
+ case 'e':
+ rc = snprintf(out_ptr, out_end - out_ptr,
+ "%s", current->comm);
+ if (rc > out_end - out_ptr)
+ goto out;
+ out_ptr += rc;
+ break;
+ default:
+ break;
+ }
+ ++pat_ptr;
+ }
+ }
+ /* Backward compatibility with core_uses_pid:
+ *
+ * If core_pattern does not include a %p (as is the default)
+ * and core_uses_pid is set, then .%pid will be appended to
+ * the filename */
+ if (!pid_in_pattern
+ && (core_uses_pid || atomic_read(¤t->mm->mm_users) != 1)) {
+ rc = snprintf(out_ptr, out_end - out_ptr,
+ ".%d", current->tgid);
+ if (rc > out_end - out_ptr)
+ goto out;
+ out_ptr += rc;
+ }
+ out:
+ *out_ptr = 0;
+}
+
+static void zap_threads (struct mm_struct *mm)
+{
+ struct task_struct *g, *p;
+ struct task_struct *tsk = current;
+ struct completion *vfork_done = tsk->vfork_done;
+ int traced = 0;
+
+ /*
+ * Make sure nobody is waiting for us to release the VM,
+ * otherwise we can deadlock when we wait on each other
+ */
+ if (vfork_done) {
+ tsk->vfork_done = NULL;
+ complete(vfork_done);
+ }
+
+ read_lock(&tasklist_lock);
+ do_each_thread(g,p)
+ if (mm == p->mm && p != tsk) {
+ force_sig_specific(SIGKILL, p);
+ mm->core_waiters++;
+ if (unlikely(p->ptrace) &&
+ unlikely(p->parent->mm == mm))
+ traced = 1;
+ }
+ while_each_thread(g,p);
+
+ read_unlock(&tasklist_lock);
+
+ if (unlikely(traced)) {
+ /*
+ * We are zapping a thread and the thread it ptraces.
+ * If the tracee went into a ptrace stop for exit tracing,
+ * we could deadlock since the tracer is waiting for this
+ * coredump to finish. Detach them so they can both die.
+ */
+ write_lock_irq(&tasklist_lock);
+ do_each_thread(g,p) {
+ if (mm == p->mm && p != tsk &&
+ p->ptrace && p->parent->mm == mm) {
+ __ptrace_unlink(p);
+ }
+ } while_each_thread(g,p);
+ write_unlock_irq(&tasklist_lock);
+ }
+}
+
+static void coredump_wait(struct mm_struct *mm)
+{
+ DECLARE_COMPLETION(startup_done);
+
+ mm->core_waiters++; /* let other threads block */
+ mm->core_startup_done = &startup_done;
+
+ /* give other threads a chance to run: */
+ yield();
+
+ zap_threads(mm);
+ if (--mm->core_waiters) {
+ up_write(&mm->mmap_sem);
+ wait_for_completion(&startup_done);
+ } else
+ up_write(&mm->mmap_sem);
+ BUG_ON(mm->core_waiters);
+}
+
+int do_coredump(long signr, int exit_code, struct pt_regs * regs)
+{
+ char corename[CORENAME_MAX_SIZE + 1];
+ struct mm_struct *mm = current->mm;
+ struct linux_binfmt * binfmt;
+ struct inode * inode;
+ struct file * file;
+ int retval = 0;
+
+ binfmt = current->binfmt;
+ if (!binfmt || !binfmt->core_dump)
+ goto fail;
+ down_write(&mm->mmap_sem);
+ if (!mm->dumpable) {
+ up_write(&mm->mmap_sem);
+ goto fail;
+ }
+ mm->dumpable = 0;
+ init_completion(&mm->core_done);
+ spin_lock_irq(¤t->sighand->siglock);
+ current->signal->flags = SIGNAL_GROUP_EXIT;
+ current->signal->group_exit_code = exit_code;
+ spin_unlock_irq(¤t->sighand->siglock);
+ coredump_wait(mm);
+
+ /*
+ * Clear any false indication of pending signals that might
+ * be seen by the filesystem code called to write the core file.
+ */
+ current->signal->group_stop_count = 0;
+ clear_thread_flag(TIF_SIGPENDING);
+
+ if (current->signal->rlim[RLIMIT_CORE].rlim_cur < binfmt->min_coredump)
+ goto fail_unlock;
+
+ /*
+ * lock_kernel() because format_corename() is controlled by sysctl, which
+ * uses lock_kernel()
+ */
+ lock_kernel();
+ format_corename(corename, core_pattern, signr);
+ unlock_kernel();
+ file = filp_open(corename, O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE, 0600);
+ if (IS_ERR(file))
+ goto fail_unlock;
+ inode = file->f_dentry->d_inode;
+ if (inode->i_nlink > 1)
+ goto close_fail; /* multiple links - don't dump */
+ if (d_unhashed(file->f_dentry))
+ goto close_fail;
+
+ if (!S_ISREG(inode->i_mode))
+ goto close_fail;
+ if (!file->f_op)
+ goto close_fail;
+ if (!file->f_op->write)
+ goto close_fail;
+ if (do_truncate(file->f_dentry, 0) != 0)
+ goto close_fail;
+
+ retval = binfmt->core_dump(signr, regs, file);
+
+ if (retval)
+ current->signal->group_exit_code |= 0x80;
+close_fail:
+ filp_close(file, NULL);
+fail_unlock:
+ complete_all(&mm->core_done);
+fail:
+ return retval;
+}