1 /*===- InstrProfilingPlatformFuchsia.c - Profile data Fuchsia platform ----===*\
2 |*
3 |* The LLVM Compiler Infrastructure
4 |*
5 |* This file is distributed under the University of Illinois Open Source
6 |* License. See LICENSE.TXT for details.
7 |*
8 \*===----------------------------------------------------------------------===*/
9 /*
10 * This file implements the profiling runtime for Fuchsia and defines the
11 * shared profile runtime interface. Each module (executable or DSO) statically
12 * links in the whole profile runtime to satisfy the calls from its
13 * instrumented code. Several modules in the same program might be separately
14 * compiled and even use different versions of the instrumentation ABI and data
15 * format. All they share in common is the VMO and the offset, which live in
16 * exported globals so that exactly one definition will be shared across all
17 * modules. Each module has its own independent runtime that registers its own
18 * atexit hook to append its own data into the shared VMO which is published
19 * via the data sink hook provided by Fuchsia's dynamic linker.
20 */
21
22 #if defined(__Fuchsia__)
23
24 #include <inttypes.h>
25 #include <stdarg.h>
26 #include <stdbool.h>
27 #include <stdlib.h>
28
29 #include <zircon/process.h>
30 #include <zircon/sanitizer.h>
31 #include <zircon/syscalls.h>
32
33 #include "InstrProfiling.h"
34 #include "InstrProfilingInternal.h"
35 #include "InstrProfilingUtil.h"
36
37 /* VMO that contains the coverage data shared across all modules. This symbol
38 * has default visibility and is exported in each module (executable or DSO)
39 * that statically links in the profiling runtime.
40 */
41 zx_handle_t __llvm_profile_vmo;
42 /* Current offset within the VMO where data should be written next. This symbol
43 * has default visibility and is exported in each module (executable or DSO)
44 * that statically links in the profiling runtime.
45 */
46 uint64_t __llvm_profile_offset;
47
48 static const char ProfileSinkName[] = "llvm-profile";
49
lprofWrite(const char * fmt,...)50 static inline void lprofWrite(const char *fmt, ...) {
51 char s[256];
52
53 va_list ap;
54 va_start(ap, fmt);
55 int ret = vsnprintf(s, sizeof(s), fmt, ap);
56 va_end(ap);
57
58 __sanitizer_log_write(s, ret + 1);
59 }
60
lprofVMOWriter(ProfDataWriter * This,ProfDataIOVec * IOVecs,uint32_t NumIOVecs)61 static uint32_t lprofVMOWriter(ProfDataWriter *This, ProfDataIOVec *IOVecs,
62 uint32_t NumIOVecs) {
63 /* Allocate VMO if it hasn't been created yet. */
64 if (__llvm_profile_vmo == ZX_HANDLE_INVALID) {
65 /* Get information about the current process. */
66 zx_info_handle_basic_t Info;
67 zx_status_t Status =
68 _zx_object_get_info(_zx_process_self(), ZX_INFO_HANDLE_BASIC, &Info,
69 sizeof(Info), NULL, NULL);
70 if (Status != ZX_OK)
71 return -1;
72
73 /* Create VMO to hold the profile data. */
74 Status = _zx_vmo_create(0, 0, &__llvm_profile_vmo);
75 if (Status != ZX_OK)
76 return -1;
77
78 /* Give the VMO a name including our process KOID so it's easy to spot. */
79 char VmoName[ZX_MAX_NAME_LEN];
80 snprintf(VmoName, sizeof(VmoName), "%s.%" PRIu64, ProfileSinkName,
81 Info.koid);
82 _zx_object_set_property(__llvm_profile_vmo, ZX_PROP_NAME, VmoName,
83 strlen(VmoName));
84
85 /* Duplicate the handle since __sanitizer_publish_data consumes it. */
86 zx_handle_t Handle;
87 Status =
88 _zx_handle_duplicate(__llvm_profile_vmo, ZX_RIGHT_SAME_RIGHTS, &Handle);
89 if (Status != ZX_OK)
90 return -1;
91
92 /* Publish the VMO which contains profile data to the system. */
93 __sanitizer_publish_data(ProfileSinkName, Handle);
94
95 /* Use the dumpfile symbolizer markup element to write the name of VMO. */
96 lprofWrite("LLVM Profile: {{{dumpfile:%s:%s}}}\n",
97 ProfileSinkName, VmoName);
98 }
99
100 /* Compute the total length of data to be written. */
101 size_t Length = 0;
102 for (uint32_t I = 0; I < NumIOVecs; I++)
103 Length += IOVecs[I].ElmSize * IOVecs[I].NumElm;
104
105 /* Resize the VMO to ensure there's sufficient space for the data. */
106 zx_status_t Status =
107 _zx_vmo_set_size(__llvm_profile_vmo, __llvm_profile_offset + Length);
108 if (Status != ZX_OK)
109 return -1;
110
111 /* Copy the data into VMO. */
112 for (uint32_t I = 0; I < NumIOVecs; I++) {
113 size_t Length = IOVecs[I].ElmSize * IOVecs[I].NumElm;
114 if (IOVecs[I].Data) {
115 Status = _zx_vmo_write(__llvm_profile_vmo, IOVecs[I].Data,
116 __llvm_profile_offset, Length);
117 if (Status != ZX_OK)
118 return -1;
119 }
120 __llvm_profile_offset += Length;
121 }
122
123 return 0;
124 }
125
initVMOWriter(ProfDataWriter * This)126 static void initVMOWriter(ProfDataWriter *This) {
127 This->Write = lprofVMOWriter;
128 This->WriterCtx = NULL;
129 }
130
dump(void)131 static int dump(void) {
132 if (lprofProfileDumped()) {
133 lprofWrite("Profile data not published: already written.\n");
134 return 0;
135 }
136
137 /* Check if there is llvm/runtime version mismatch. */
138 if (GET_VERSION(__llvm_profile_get_version()) != INSTR_PROF_RAW_VERSION) {
139 lprofWrite("Runtime and instrumentation version mismatch : "
140 "expected %d, but got %d\n",
141 INSTR_PROF_RAW_VERSION,
142 (int)GET_VERSION(__llvm_profile_get_version()));
143 return -1;
144 }
145
146 /* Write the profile data into the mapped region. */
147 ProfDataWriter VMOWriter;
148 initVMOWriter(&VMOWriter);
149 if (lprofWriteData(&VMOWriter, lprofGetVPDataReader(), 0) != 0)
150 return -1;
151
152 return 0;
153 }
154
155 COMPILER_RT_VISIBILITY
__llvm_profile_dump(void)156 int __llvm_profile_dump(void) {
157 int rc = dump();
158 lprofSetProfileDumped();
159 return rc;
160 }
161
dumpWithoutReturn(void)162 static void dumpWithoutReturn(void) { dump(); }
163
164 /* This method is invoked by the runtime initialization hook
165 * InstrProfilingRuntime.o if it is linked in.
166 */
167 COMPILER_RT_VISIBILITY
__llvm_profile_initialize_file(void)168 void __llvm_profile_initialize_file(void) {}
169
170 COMPILER_RT_VISIBILITY
__llvm_profile_register_write_file_atexit(void)171 int __llvm_profile_register_write_file_atexit(void) {
172 static bool HasBeenRegistered = false;
173
174 if (HasBeenRegistered)
175 return 0;
176
177 lprofSetupValueProfiler();
178
179 HasBeenRegistered = true;
180 return atexit(dumpWithoutReturn);
181 }
182
183 #endif
184