-/*
+/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
+ *
* 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 "lttng-probe-user.h"
+#include <linux/module.h>
+#include <wrapper/uaccess.h>
+#include <probes/lttng-probe-user.h>
+
+#define LTTNG_MAX_USER_STRING_LEN 1048576 /* 1MB */
/*
* Calculate string length. Include final null terminating character if there is
long lttng_strlen_user_inatomic(const char *addr)
{
long count = 0;
- mm_segment_t old_fs = get_fs();
- set_fs(KERNEL_DS);
+ if (!addr)
+ return 0;
+
pagefault_disable();
for (;;) {
char v;
unsigned long ret;
+ if (unlikely(!lttng_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(count > LTTNG_MAX_USER_STRING_LEN))
+ break;
if (unlikely(!v))
break;
addr++;
}
pagefault_enable();
- set_fs(old_fs);
return count;
}
+EXPORT_SYMBOL_GPL(lttng_strlen_user_inatomic);