+/*
+ * uhm_pipe_setup
+ * helper function to customize the process used
+ * to collect the core in userspace. Specifically
+ * it sets up a pipe and installs it as fd 0 (stdin)
+ * for the process. Returns 0 on success, or
+ * PTR_ERR on failure.
+ * Note that it also sets the core limit to 1. This
+ * is a special value that we use to trap recursive
+ * core dumps
+ */
+static int umh_pipe_setup(struct subprocess_info *info)
+{
+ struct file *rp, *wp;
+ struct fdtable *fdt;
+ struct coredump_params *cp = (struct coredump_params *)info->data;
+ struct files_struct *cf = current->files;
+
+ wp = create_write_pipe(0);
+ if (IS_ERR(wp))
+ return PTR_ERR(wp);
+
+ rp = create_read_pipe(wp, 0);
+ if (IS_ERR(rp)) {
+ free_write_pipe(wp);
+ return PTR_ERR(rp);
+ }
+
+ cp->file = wp;
+
+ sys_close(0);
+ fd_install(0, rp);
+ spin_lock(&cf->file_lock);
+ fdt = files_fdtable(cf);
+ FD_SET(0, fdt->open_fds);
+ FD_CLR(0, fdt->close_on_exec);
+ spin_unlock(&cf->file_lock);
+
+ /* and disallow core files too */
+ current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1};
+
+ return 0;
+}
+