1 /*
2 * Copyright (C) 2017 Citrix Systems R&D
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <xen/errno.h>
28 #include <xen/guest_access.h>
29 #include <xen/types.h>
30
31 #include "coverage.h"
32
33 #ifndef __clang__
34 #error "LLVM coverage selected without clang compiler"
35 #endif
36
37 #if BITS_PER_LONG == 64
38 #define LLVM_PROFILE_MAGIC (((uint64_t)255 << 56) | ((uint64_t)'l' << 48) | \
39 ((uint64_t)'p' << 40) | ((uint64_t)'r' << 32) | ((uint64_t)'o' << 24) | \
40 ((uint64_t)'f' << 16) | ((uint64_t)'r' << 8) | ((uint64_t)129))
41 #else
42 #define LLVM_PROFILE_MAGIC (((uint64_t)255 << 56) | ((uint64_t)'l' << 48) | \
43 ((uint64_t)'p' << 40) | ((uint64_t)'r' << 32) | ((uint64_t)'o' << 24) | \
44 ((uint64_t)'f' << 16) | ((uint64_t)'R' << 8) | ((uint64_t)129)
45 #endif
46
47 #define LLVM_PROFILE_VERSION 4
48 #define LLVM_PROFILE_NUM_KINDS 2
49
50 struct llvm_profile_data {
51 uint64_t name_ref;
52 uint64_t function_hash;
53 void *counter;
54 void *function;
55 void *values;
56 uint32_t nr_counters;
57 uint16_t nr_value_sites[LLVM_PROFILE_NUM_KINDS];
58 };
59
60 struct llvm_profile_header {
61 uint64_t magic;
62 uint64_t version;
63 uint64_t data_size;
64 uint64_t counters_size;
65 uint64_t names_size;
66 uint64_t counters_delta;
67 uint64_t names_delta;
68 uint64_t value_kind_last;
69 };
70
71 /*
72 * Since Xen uses the llvm code coverage support without the run time library
73 * __llvm_profile_runtime must be defined according to the docs at:
74 *
75 * https://clang.llvm.org/docs/SourceBasedCodeCoverage.html
76 */
77 int __llvm_profile_runtime;
78
79 extern const struct llvm_profile_data __start___llvm_prf_data[];
80 extern const struct llvm_profile_data __stop___llvm_prf_data[];
81 extern const char __start___llvm_prf_names[];
82 extern const char __stop___llvm_prf_names[];
83 extern uint64_t __start___llvm_prf_cnts[];
84 extern uint64_t __stop___llvm_prf_cnts[];
85
86 #define START_DATA ((const void *)__start___llvm_prf_data)
87 #define END_DATA ((const void *)__stop___llvm_prf_data)
88 #define START_NAMES ((const void *)__start___llvm_prf_names)
89 #define END_NAMES ((const void *)__stop___llvm_prf_names)
90 #define START_COUNTERS ((void *)__start___llvm_prf_cnts)
91 #define END_COUNTERS ((void *)__stop___llvm_prf_cnts)
92
reset_counters(void)93 static void cf_check reset_counters(void)
94 {
95 memset(START_COUNTERS, 0, END_COUNTERS - START_COUNTERS);
96 }
97
get_size(void)98 static uint32_t cf_check get_size(void)
99 {
100 return ROUNDUP(sizeof(struct llvm_profile_header) + END_DATA - START_DATA +
101 END_COUNTERS - START_COUNTERS + END_NAMES - START_NAMES, 8);
102 }
103
dump(XEN_GUEST_HANDLE_PARAM (char)buffer,uint32_t * buf_size)104 static int cf_check dump(
105 XEN_GUEST_HANDLE_PARAM(char) buffer, uint32_t *buf_size)
106 {
107 struct llvm_profile_header header = {
108 .magic = LLVM_PROFILE_MAGIC,
109 .version = LLVM_PROFILE_VERSION,
110 .data_size = (END_DATA - START_DATA) / sizeof(struct llvm_profile_data),
111 .counters_size = (END_COUNTERS - START_COUNTERS) / sizeof(uint64_t),
112 .names_size = END_NAMES - START_NAMES,
113 .counters_delta = (uintptr_t)START_COUNTERS,
114 .names_delta = (uintptr_t)START_NAMES,
115 .value_kind_last = LLVM_PROFILE_NUM_KINDS - 1,
116 };
117 unsigned int off = 0;
118
119 #define APPEND_TO_BUFFER(src, size) \
120 ({ \
121 if ( off + (size) > *buf_size ) \
122 return -ENOMEM; \
123 copy_to_guest_offset(buffer, off, (const char *)src, size); \
124 off += (size); \
125 })
126 APPEND_TO_BUFFER(&header, sizeof(header));
127 APPEND_TO_BUFFER(START_DATA, END_DATA - START_DATA);
128 APPEND_TO_BUFFER(START_COUNTERS, END_COUNTERS - START_COUNTERS);
129 APPEND_TO_BUFFER(START_NAMES, END_NAMES - START_NAMES);
130 #undef APPEND_TO_BUFFER
131
132 clear_guest_offset(buffer, off, *buf_size - off);
133
134 return 0;
135 }
136
137 const struct cov_sysctl_ops cov_ops = {
138 .get_size = get_size,
139 .reset_counters = reset_counters,
140 .dump = dump,
141 };
142
143 /*
144 * Local variables:
145 * mode: C
146 * c-file-style: "BSD"
147 * c-basic-offset: 4
148 * tab-width: 4
149 * indent-tabs-mode: nil
150 * End:
151 */
152