1 /*===- InstrProfilingPlatformFuchsia.c - Profile data Fuchsia platform ----===*\
2 |*
3 |* Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 |* See https://llvm.org/LICENSE.txt for license information.
5 |* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 |*
7 \*===----------------------------------------------------------------------===*/
8 /*
9 * This file implements the profiling runtime for Fuchsia and defines the
10 * shared profile runtime interface. Each module (executable or DSO) statically
11 * links in the whole profile runtime to satisfy the calls from its
12 * instrumented code. Several modules in the same program might be separately
13 * compiled and even use different versions of the instrumentation ABI and data
14 * format. All they share in common is the VMO and the offset, which live in
15 * exported globals so that exactly one definition will be shared across all
16 * modules. Each module has its own independent runtime that registers its own
17 * atexit hook to append its own data into the shared VMO which is published
18 * via the data sink hook provided by Fuchsia's dynamic linker.
19 */
20
21 #if defined(__Fuchsia__)
22
23 #include <inttypes.h>
24 #include <stdarg.h>
25 #include <stdbool.h>
26 #include <stdlib.h>
27
28 #include <zircon/process.h>
29 #include <zircon/sanitizer.h>
30 #include <zircon/status.h>
31 #include <zircon/syscalls.h>
32
33 #include "InstrProfiling.h"
34 #include "InstrProfilingInternal.h"
35 #include "InstrProfilingUtil.h"
36
lprofProfileDumped()37 COMPILER_RT_VISIBILITY unsigned lprofProfileDumped() {
38 return 1;
39 }
lprofSetProfileDumped(unsigned Value)40 COMPILER_RT_VISIBILITY void lprofSetProfileDumped(unsigned Value) {}
41
lprofRuntimeCounterRelocation(void)42 COMPILER_RT_VISIBILITY unsigned lprofRuntimeCounterRelocation(void) {
43 return 1;
44 }
lprofSetRuntimeCounterRelocation(unsigned Value)45 COMPILER_RT_VISIBILITY void lprofSetRuntimeCounterRelocation(unsigned Value) {}
46
47 static const char ProfileSinkName[] = "llvm-profile";
48
lprofWrite(const char * fmt,...)49 static inline void lprofWrite(const char *fmt, ...) {
50 char s[256];
51
52 va_list ap;
53 va_start(ap, fmt);
54 int ret = vsnprintf(s, sizeof(s), fmt, ap);
55 va_end(ap);
56
57 __sanitizer_log_write(s, ret + 1);
58 }
59
60 struct lprofVMOWriterCtx {
61 /* VMO that contains the profile data for this module. */
62 zx_handle_t Vmo;
63 /* Current offset within the VMO where data should be written next. */
64 uint64_t Offset;
65 };
66
lprofVMOWriter(ProfDataWriter * This,ProfDataIOVec * IOVecs,uint32_t NumIOVecs)67 static uint32_t lprofVMOWriter(ProfDataWriter *This, ProfDataIOVec *IOVecs,
68 uint32_t NumIOVecs) {
69 struct lprofVMOWriterCtx *Ctx = (struct lprofVMOWriterCtx *)This->WriterCtx;
70
71 /* Compute the total length of data to be written. */
72 size_t Length = 0;
73 for (uint32_t I = 0; I < NumIOVecs; I++)
74 Length += IOVecs[I].ElmSize * IOVecs[I].NumElm;
75
76 /* Resize the VMO to ensure there's sufficient space for the data. */
77 zx_status_t Status = _zx_vmo_set_size(Ctx->Vmo, Ctx->Offset + Length);
78 if (Status != ZX_OK)
79 return -1;
80
81 /* Copy the data into VMO. */
82 for (uint32_t I = 0; I < NumIOVecs; I++) {
83 size_t Length = IOVecs[I].ElmSize * IOVecs[I].NumElm;
84 if (IOVecs[I].Data) {
85 Status = _zx_vmo_write(Ctx->Vmo, IOVecs[I].Data, Ctx->Offset, Length);
86 if (Status != ZX_OK)
87 return -1;
88 } else if (IOVecs[I].UseZeroPadding) {
89 /* Resizing the VMO should zero fill. */
90 }
91 Ctx->Offset += Length;
92 }
93
94 /* Record the profile size as a property of the VMO. */
95 _zx_object_set_property(Ctx->Vmo, ZX_PROP_VMO_CONTENT_SIZE, &Ctx->Offset,
96 sizeof(Ctx->Offset));
97
98 return 0;
99 }
100
initVMOWriter(ProfDataWriter * This,struct lprofVMOWriterCtx * Ctx)101 static void initVMOWriter(ProfDataWriter *This, struct lprofVMOWriterCtx *Ctx) {
102 This->Write = lprofVMOWriter;
103 This->WriterCtx = Ctx;
104 }
105
106 /* This method is invoked by the runtime initialization hook
107 * InstrProfilingRuntime.o if it is linked in. */
108 COMPILER_RT_VISIBILITY
__llvm_profile_initialize(void)109 void __llvm_profile_initialize(void) {
110 /* Check if there is llvm/runtime version mismatch. */
111 if (GET_VERSION(__llvm_profile_get_version()) != INSTR_PROF_RAW_VERSION) {
112 lprofWrite("LLVM Profile: runtime and instrumentation version mismatch: "
113 "expected %d, but got %d\n",
114 INSTR_PROF_RAW_VERSION,
115 (int)GET_VERSION(__llvm_profile_get_version()));
116 return;
117 }
118
119 /* This symbol is defined as weak and initialized to -1 by the runtimer, but
120 * compiler will generate a strong definition initialized to 0 when runtime
121 * counter relocation is used. */
122 if (__llvm_profile_counter_bias == -1) {
123 lprofWrite("LLVM Profile: counter relocation at runtime is required\n");
124 return;
125 }
126
127 const __llvm_profile_data *DataBegin = __llvm_profile_begin_data();
128 const __llvm_profile_data *DataEnd = __llvm_profile_end_data();
129 const uint64_t DataSize = __llvm_profile_get_data_size(DataBegin, DataEnd);
130 const uint64_t CountersOffset =
131 sizeof(__llvm_profile_header) + (DataSize * sizeof(__llvm_profile_data));
132
133 zx_status_t Status;
134
135 /* Create VMO to hold the profile data. */
136 zx_handle_t Vmo = ZX_HANDLE_INVALID;
137 Status = _zx_vmo_create(0, ZX_VMO_RESIZABLE, &Vmo);
138 if (Status != ZX_OK) {
139 lprofWrite("LLVM Profile: cannot create VMO: %s\n",
140 _zx_status_get_string(Status));
141 return;
142 }
143
144 /* Give the VMO a name that includes the module signature. */
145 char VmoName[ZX_MAX_NAME_LEN];
146 snprintf(VmoName, sizeof(VmoName), "%" PRIu64 ".profraw",
147 lprofGetLoadModuleSignature());
148 _zx_object_set_property(Vmo, ZX_PROP_NAME, VmoName, strlen(VmoName));
149
150 /* Write the profile data into the mapped region. */
151 ProfDataWriter VMOWriter;
152 struct lprofVMOWriterCtx Ctx = {.Vmo = Vmo, .Offset = 0};
153 initVMOWriter(&VMOWriter, &Ctx);
154 if (lprofWriteData(&VMOWriter, 0, 0) != 0) {
155 lprofWrite("LLVM Profile: failed to write data\n");
156 _zx_handle_close(Vmo);
157 return;
158 }
159
160 uint64_t Len = 0;
161 Status = _zx_vmo_get_size(Vmo, &Len);
162 if (Status != ZX_OK) {
163 lprofWrite("LLVM Profile: failed to get the VMO size: %s\n",
164 _zx_status_get_string(Status));
165 _zx_handle_close(Vmo);
166 return;
167 }
168
169 uintptr_t Mapping;
170 Status =
171 _zx_vmar_map(_zx_vmar_root_self(), ZX_VM_PERM_READ | ZX_VM_PERM_WRITE, 0,
172 Vmo, 0, Len, &Mapping);
173 if (Status != ZX_OK) {
174 lprofWrite("LLVM Profile: failed to map the VMO: %s\n",
175 _zx_status_get_string(Status));
176 _zx_handle_close(Vmo);
177 return;
178 }
179
180 /* Publish the VMO which contains profile data to the system. Note that this
181 * also consumes the VMO handle. */
182 __sanitizer_publish_data(ProfileSinkName, Vmo);
183
184 /* Use the dumpfile symbolizer markup element to write the name of VMO. */
185 lprofWrite("LLVM Profile: {{{dumpfile:%s:%s}}}\n", ProfileSinkName, VmoName);
186
187 /* Update the profile fields based on the current mapping. */
188 __llvm_profile_counter_bias = (intptr_t)Mapping -
189 (uintptr_t)__llvm_profile_begin_counters() +
190 CountersOffset;
191 }
192
193 #endif
194