1 /*
2 * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
3 * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without modification,
6 * are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this list of
9 * conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice, this list
12 * of conditions and the following disclaimer in the documentation and/or other materials
13 * provided with the distribution.
14 *
15 * 3. Neither the name of the copyright holder nor the names of its contributors may be used
16 * to endorse or promote products derived from this software without specific prior written
17 * permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
21 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include "asm/page.h"
33 #include "time.h"
34 #include "sys/time.h"
35 #include "los_typedef.h"
36 #include "los_vdso_datapage.h"
37
VdsoGetRealtimeCoarse(struct timespec * ts,const VdsoDataPage * usrVdsoDataPage)38 STATIC INT32 VdsoGetRealtimeCoarse(struct timespec *ts, const VdsoDataPage *usrVdsoDataPage)
39 {
40 do {
41 if (!usrVdsoDataPage->lockCount) {
42 ts->tv_sec = usrVdsoDataPage->realTimeSec;
43 ts->tv_nsec = usrVdsoDataPage->realTimeNsec;
44 return 0;
45 }
46 } while (1);
47 }
48
VdsoGetMonotimeCoarse(struct timespec * ts,const VdsoDataPage * usrVdsoDataPage)49 STATIC INT32 VdsoGetMonotimeCoarse(struct timespec *ts, const VdsoDataPage *usrVdsoDataPage)
50 {
51 do {
52 if (!usrVdsoDataPage->lockCount) {
53 ts->tv_sec = usrVdsoDataPage->monoTimeSec;
54 ts->tv_nsec = usrVdsoDataPage->monoTimeNsec;
55 return 0;
56 }
57 } while (1);
58 }
59
LocVdsoStart(size_t vdsoStart,const CHAR * elfHead,const size_t len)60 STATIC size_t LocVdsoStart(size_t vdsoStart, const CHAR *elfHead, const size_t len)
61 {
62 CHAR *head = NULL;
63 INT32 i;
64 INT32 loop;
65
66 for (i = 1; i <= MAX_PAGES; i++) {
67 head = (CHAR *)((UINTPTR)vdsoStart);
68 for (loop = len; loop >= 1; loop--) {
69 if (*head++ != *(elfHead + len - loop)) {
70 break;
71 }
72 }
73 if (loop) {
74 vdsoStart -= PAGE_SIZE;
75 } else {
76 break;
77 }
78 }
79
80 if (i > MAX_PAGES) {
81 return 0;
82 }
83 return (vdsoStart - PAGE_SIZE);
84 }
85
VdsoClockGettime(clockid_t clk,struct timespec * ts)86 INT32 VdsoClockGettime(clockid_t clk, struct timespec *ts)
87 {
88 INT32 ret;
89 size_t vdsoStart;
90
91 __asm__ __volatile__("mov %0, pc" : "=r"(vdsoStart));
92 vdsoStart = vdsoStart - (vdsoStart & (PAGE_SIZE - 1));
93 vdsoStart = LocVdsoStart(vdsoStart, ELF_HEAD, ELF_HEAD_LEN);
94 if (vdsoStart == 0) {
95 return -1;
96 }
97
98 VdsoDataPage *usrVdsoDataPage = (VdsoDataPage *)(UINTPTR)vdsoStart;
99
100 switch (clk) {
101 case CLOCK_REALTIME_COARSE:
102 ret = VdsoGetRealtimeCoarse(ts, usrVdsoDataPage);
103 break;
104 case CLOCK_MONOTONIC_COARSE:
105 ret = VdsoGetMonotimeCoarse(ts, usrVdsoDataPage);
106 break;
107 default:
108 ret = -1;
109 break;
110 }
111
112 return ret;
113 }
114