+++ /dev/null
-/*
- * lttng-probe-user.c
- *
- * Copyright (C) 2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; only
- * version 2.1 of the License.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include <linux/uaccess.h>
-#include <linux/module.h>
-#include <probes/lttng-probe-user.h>
-
-/*
- * Calculate string length. Include final null terminating character if there is
- * one, or ends at first fault. Disabling page faults ensures that we can safely
- * call this from pretty much any context, including those where the caller
- * holds mmap_sem, or any lock which nests in mmap_sem.
- */
-long lttng_strlen_user_inatomic(const char *addr)
-{
- long count = 0;
- mm_segment_t old_fs = get_fs();
-
- set_fs(KERNEL_DS);
- pagefault_disable();
- for (;;) {
- char v;
- unsigned long ret;
-
- if (unlikely(!access_ok(VERIFY_READ,
- (__force const char __user *) addr,
- sizeof(v))))
- break;
- ret = __copy_from_user_inatomic(&v,
- (__force const char __user *)(addr),
- sizeof(v));
- if (unlikely(ret > 0))
- break;
- count++;
- if (unlikely(!v))
- break;
- addr++;
- }
- pagefault_enable();
- set_fs(old_fs);
- return count;
-}
-EXPORT_SYMBOL_GPL(lttng_strlen_user_inatomic);