| 1 | /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) |
| 2 | * |
| 3 | * lttng/probe-user.h |
| 4 | * |
| 5 | * Copyright (C) 2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 6 | */ |
| 7 | |
| 8 | #ifndef _LTTNG_PROBE_USER_H |
| 9 | #define _LTTNG_PROBE_USER_H |
| 10 | |
| 11 | #include <wrapper/uaccess.h> |
| 12 | |
| 13 | /* |
| 14 | * Calculate string length. Include final null terminating character if there is |
| 15 | * one, or ends at first fault. |
| 16 | */ |
| 17 | long lttng_strlen_user_inatomic(const char *addr); |
| 18 | |
| 19 | /* |
| 20 | * We use __copy_from_user_inatomic to copy userspace data after |
| 21 | * checking with access_ok() and disabling page faults. |
| 22 | * |
| 23 | * Return 0 if OK, nonzero on error. |
| 24 | */ |
| 25 | static inline |
| 26 | unsigned long lttng_copy_from_user_check_nofault(void *dest, |
| 27 | const void __user *src, |
| 28 | unsigned long len) |
| 29 | { |
| 30 | unsigned long ret; |
| 31 | |
| 32 | if (!lttng_access_ok(VERIFY_READ, src, len)) |
| 33 | return 1; |
| 34 | pagefault_disable(); |
| 35 | ret = __copy_from_user_inatomic(dest, src, len); |
| 36 | pagefault_enable(); |
| 37 | return ret; |
| 38 | } |
| 39 | |
| 40 | #endif /* _LTTNG_PROBE_USER_H */ |