Linux-2.6.12-rc2v2.6.12-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!

1 files changed, 1498 insertions, 0 deletions

diff --git a/fs/exec.c b/fs/exec.c
new file mode 100644
index 000000000000..a8394499926c
--- /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(&current->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(&current->tasks);
+                list_add_tail(&current->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(&current->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(&current->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(&current->sighand->siglock);
+        current->signal->flags = SIGNAL_GROUP_EXIT;
+        current->signal->group_exit_code = exit_code;
+        spin_unlock_irq(&current->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;
+}