1 /*
2 * Copyright (c) 2013-2019, Intel Corporation
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * * Redistributions of source code must retain the above copyright notice,
8 * this list of conditions and the following disclaimer.
9 * * Redistributions in binary form must reproduce the above copyright notice,
10 * this list of conditions and the following disclaimer in the documentation
11 * and/or other materials provided with the distribution.
12 * * Neither the name of Intel Corporation nor the names of its contributors
13 * may be used to endorse or promote products derived from this software
14 * without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include "pt_retstack.h"
30
31 #include "intel-pt.h"
32
33
pt_retstack_init(struct pt_retstack * retstack)34 void pt_retstack_init(struct pt_retstack *retstack)
35 {
36 if (!retstack)
37 return;
38
39 retstack->top = 0;
40 retstack->bottom = 0;
41 }
42
pt_retstack_is_empty(const struct pt_retstack * retstack)43 int pt_retstack_is_empty(const struct pt_retstack *retstack)
44 {
45 if (!retstack)
46 return -pte_invalid;
47
48 return (retstack->top == retstack->bottom ? 1 : 0);
49 }
50
pt_retstack_pop(struct pt_retstack * retstack,uint64_t * ip)51 int pt_retstack_pop(struct pt_retstack *retstack, uint64_t *ip)
52 {
53 uint8_t top;
54
55 if (!retstack)
56 return -pte_invalid;
57
58 top = retstack->top;
59
60 if (top == retstack->bottom)
61 return -pte_retstack_empty;
62
63 top = (!top ? pt_retstack_size : top - 1);
64
65 retstack->top = top;
66
67 if (ip)
68 *ip = retstack->stack[top];
69
70 return 0;
71 }
72
pt_retstack_push(struct pt_retstack * retstack,uint64_t ip)73 int pt_retstack_push(struct pt_retstack *retstack, uint64_t ip)
74 {
75 uint8_t top, bottom;
76
77 if (!retstack)
78 return -pte_invalid;
79
80 top = retstack->top;
81 bottom = retstack->bottom;
82
83 retstack->stack[top] = ip;
84
85 top = (top == pt_retstack_size ? 0 : top + 1);
86
87 if (bottom == top)
88 bottom = (bottom == pt_retstack_size ? 0 : bottom + 1);
89
90 retstack->top = top;
91 retstack->bottom = bottom;
92
93 return 0;
94 }
95