-static int expand_corename(struct core_name *cn)
-{
- char *old_corename = cn->corename;
-
- cn->size = CORENAME_MAX_SIZE * atomic_inc_return(&call_count);
- cn->corename = krealloc(old_corename, cn->size, GFP_KERNEL);
-
- if (!cn->corename) {
- kfree(old_corename);
- return -ENOMEM;
- }
-
- return 0;
-}
-
-static int cn_printf(struct core_name *cn, const char *fmt, ...)
-{
- char *cur;
- int need;
- int ret;
- va_list arg;
-
- va_start(arg, fmt);
- need = vsnprintf(NULL, 0, fmt, arg);
- va_end(arg);
-
- if (likely(need < cn->size - cn->used - 1))
- goto out_printf;
-
- ret = expand_corename(cn);
- if (ret)
- goto expand_fail;
-
-out_printf:
- cur = cn->corename + cn->used;
- va_start(arg, fmt);
- vsnprintf(cur, need + 1, fmt, arg);
- va_end(arg);
- cn->used += need;
- return 0;
-
-expand_fail:
- return ret;
-}
-
-static void cn_escape(char *str)
-{
- for (; *str; str++)
- if (*str == '/')
- *str = '!';
-}
-
-static int cn_print_exe_file(struct core_name *cn)
-{
- struct file *exe_file;
- char *pathbuf, *path;
- int ret;
-
- exe_file = get_mm_exe_file(current->mm);
- if (!exe_file) {
- char *commstart = cn->corename + cn->used;
- ret = cn_printf(cn, "%s (path unknown)", current->comm);
- cn_escape(commstart);
- return ret;
- }
-
- pathbuf = kmalloc(PATH_MAX, GFP_TEMPORARY);
- if (!pathbuf) {
- ret = -ENOMEM;
- goto put_exe_file;
- }
-
- path = d_path(&exe_file->f_path, pathbuf, PATH_MAX);
- if (IS_ERR(path)) {
- ret = PTR_ERR(path);
- goto free_buf;
- }
-
- cn_escape(path);
-
- ret = cn_printf(cn, "%s", path);
-
-free_buf:
- kfree(pathbuf);
-put_exe_file:
- fput(exe_file);
- return ret;
-}
-
-/* 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 int format_corename(struct core_name *cn, long signr)
-{
- const struct cred *cred = current_cred();
- const char *pat_ptr = core_pattern;
- int ispipe = (*pat_ptr == '|');
- int pid_in_pattern = 0;
- int err = 0;
-
- cn->size = CORENAME_MAX_SIZE * atomic_read(&call_count);
- cn->corename = kmalloc(cn->size, GFP_KERNEL);
- cn->used = 0;
-
- if (!cn->corename)
- return -ENOMEM;
-
- /* Repeat as long as we have more pattern to process and more output
- space */
- while (*pat_ptr) {
- if (*pat_ptr != '%') {
- if (*pat_ptr == 0)
- goto out;
- err = cn_printf(cn, "%c", *pat_ptr++);
- } else {
- switch (*++pat_ptr) {
- /* single % at the end, drop that */
- case 0:
- goto out;
- /* Double percent, output one percent */
- case '%':
- err = cn_printf(cn, "%c", '%');
- break;
- /* pid */
- case 'p':
- pid_in_pattern = 1;
- err = cn_printf(cn, "%d",
- task_tgid_vnr(current));
- break;
- /* uid */
- case 'u':
- err = cn_printf(cn, "%d", cred->uid);
- break;
- /* gid */
- case 'g':
- err = cn_printf(cn, "%d", cred->gid);
- break;
- /* signal that caused the coredump */
- case 's':
- err = cn_printf(cn, "%ld", signr);
- break;
- /* UNIX time of coredump */
- case 't': {
- struct timeval tv;
- do_gettimeofday(&tv);
- err = cn_printf(cn, "%lu", tv.tv_sec);
- break;
- }
- /* hostname */
- case 'h': {
- char *namestart = cn->corename + cn->used;
- down_read(&uts_sem);
- err = cn_printf(cn, "%s",
- utsname()->nodename);
- up_read(&uts_sem);
- cn_escape(namestart);
- break;
- }
- /* executable */
- case 'e': {
- char *commstart = cn->corename + cn->used;
- err = cn_printf(cn, "%s", current->comm);
- cn_escape(commstart);
- break;
- }
- case 'E':
- err = cn_print_exe_file(cn);
- break;
- /* core limit size */
- case 'c':
- err = cn_printf(cn, "%lu",
- rlimit(RLIMIT_CORE));
- break;
- default:
- break;
- }
- ++pat_ptr;
- }
-
- if (err)
- return err;
- }
-
- /* 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. Do not do this for piped commands. */
- if (!ispipe && !pid_in_pattern && core_uses_pid) {
- err = cn_printf(cn, ".%d", task_tgid_vnr(current));
- if (err)
- return err;
- }
-out:
- return ispipe;
-}
-
-static int zap_process(struct task_struct *start, int exit_code)
-{
- struct task_struct *t;
- int nr = 0;
-
- start->signal->flags = SIGNAL_GROUP_EXIT;
- start->signal->group_exit_code = exit_code;
- start->signal->group_stop_count = 0;
-
- t = start;
- do {
- task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK);
- if (t != current && t->mm) {
- sigaddset(&t->pending.signal, SIGKILL);
- signal_wake_up(t, 1);
- nr++;
- }
- } while_each_thread(start, t);
-
- return nr;
-}
-
-static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
- struct core_state *core_state, int exit_code)
-{
- struct task_struct *g, *p;
- unsigned long flags;
- int nr = -EAGAIN;
-
- spin_lock_irq(&tsk->sighand->siglock);
- if (!signal_group_exit(tsk->signal)) {
- mm->core_state = core_state;
- nr = zap_process(tsk, exit_code);
- }
- spin_unlock_irq(&tsk->sighand->siglock);
- if (unlikely(nr < 0))
- return nr;
-
- if (atomic_read(&mm->mm_users) == nr + 1)
- goto done;
- /*
- * We should find and kill all tasks which use this mm, and we should
- * count them correctly into ->nr_threads. We don't take tasklist
- * lock, but this is safe wrt:
- *
- * fork:
- * None of sub-threads can fork after zap_process(leader). All
- * processes which were created before this point should be
- * visible to zap_threads() because copy_process() adds the new
- * process to the tail of init_task.tasks list, and lock/unlock
- * of ->siglock provides a memory barrier.
- *
- * do_exit:
- * The caller holds mm->mmap_sem. This means that the task which
- * uses this mm can't pass exit_mm(), so it can't exit or clear
- * its ->mm.
- *
- * de_thread:
- * It does list_replace_rcu(&leader->tasks, ¤t->tasks),
- * we must see either old or new leader, this does not matter.
- * However, it can change p->sighand, so lock_task_sighand(p)
- * must be used. Since p->mm != NULL and we hold ->mmap_sem
- * it can't fail.
- *
- * Note also that "g" can be the old leader with ->mm == NULL
- * and already unhashed and thus removed from ->thread_group.
- * This is OK, __unhash_process()->list_del_rcu() does not
- * clear the ->next pointer, we will find the new leader via
- * next_thread().
- */
- rcu_read_lock();
- for_each_process(g) {
- if (g == tsk->group_leader)
- continue;
- if (g->flags & PF_KTHREAD)
- continue;
- p = g;
- do {
- if (p->mm) {
- if (unlikely(p->mm == mm)) {
- lock_task_sighand(p, &flags);
- nr += zap_process(p, exit_code);
- unlock_task_sighand(p, &flags);
- }
- break;
- }
- } while_each_thread(g, p);
- }
- rcu_read_unlock();
-done:
- atomic_set(&core_state->nr_threads, nr);
- return nr;
-}
-
-static int coredump_wait(int exit_code, struct core_state *core_state)
-{
- struct task_struct *tsk = current;
- struct mm_struct *mm = tsk->mm;
- int core_waiters = -EBUSY;
-
- init_completion(&core_state->startup);
- core_state->dumper.task = tsk;
- core_state->dumper.next = NULL;
-
- down_write(&mm->mmap_sem);
- if (!mm->core_state)
- core_waiters = zap_threads(tsk, mm, core_state, exit_code);
- up_write(&mm->mmap_sem);
-
- if (core_waiters > 0) {
- struct core_thread *ptr;
-
- wait_for_completion(&core_state->startup);
- /*
- * Wait for all the threads to become inactive, so that
- * all the thread context (extended register state, like
- * fpu etc) gets copied to the memory.
- */
- ptr = core_state->dumper.next;
- while (ptr != NULL) {
- wait_task_inactive(ptr->task, 0);
- ptr = ptr->next;
- }
- }
-
- return core_waiters;
-}
-
-static void coredump_finish(struct mm_struct *mm)
-{
- struct core_thread *curr, *next;
- struct task_struct *task;
-
- next = mm->core_state->dumper.next;
- while ((curr = next) != NULL) {
- next = curr->next;
- task = curr->task;
- /*
- * see exit_mm(), curr->task must not see
- * ->task == NULL before we read ->next.
- */
- smp_mb();
- curr->task = NULL;
- wake_up_process(task);
- }
-
- mm->core_state = NULL;
-}
-