1 //===-- fuchsia.cpp ---------------------------------------------*- C++ -*-===// 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 #include "platform.h" 10 11 #if SCUDO_FUCHSIA 12 13 #include "common.h" 14 #include "mutex.h" 15 #include "string_utils.h" 16 17 #include <lib/sync/mutex.h> // for sync_mutex_t 18 #include <stdlib.h> // for getenv() 19 #include <zircon/compiler.h> 20 #include <zircon/process.h> 21 #include <zircon/sanitizer.h> 22 #include <zircon/status.h> 23 #include <zircon/syscalls.h> 24 25 namespace scudo { 26 27 uptr getPageSize() { return _zx_system_get_page_size(); } 28 29 void NORETURN die() { __builtin_trap(); } 30 31 // We zero-initialize the Extra parameter of map(), make sure this is consistent 32 // with ZX_HANDLE_INVALID. 33 static_assert(ZX_HANDLE_INVALID == 0, ""); 34 35 static void NORETURN dieOnError(zx_status_t Status, const char *FnName, 36 uptr Size) { 37 ScopedString Error; 38 Error.append("SCUDO ERROR: %s failed with size %zuKB (%s)", FnName, 39 Size >> 10, zx_status_get_string(Status)); 40 outputRaw(Error.data()); 41 die(); 42 } 43 44 static void *allocateVmar(uptr Size, MapPlatformData *Data, bool AllowNoMem) { 45 // Only scenario so far. 46 DCHECK(Data); 47 DCHECK_EQ(Data->Vmar, ZX_HANDLE_INVALID); 48 49 const zx_status_t Status = _zx_vmar_allocate( 50 _zx_vmar_root_self(), 51 ZX_VM_CAN_MAP_READ | ZX_VM_CAN_MAP_WRITE | ZX_VM_CAN_MAP_SPECIFIC, 0, 52 Size, &Data->Vmar, &Data->VmarBase); 53 if (UNLIKELY(Status != ZX_OK)) { 54 if (Status != ZX_ERR_NO_MEMORY || !AllowNoMem) 55 dieOnError(Status, "zx_vmar_allocate", Size); 56 return nullptr; 57 } 58 return reinterpret_cast<void *>(Data->VmarBase); 59 } 60 61 void *map(void *Addr, uptr Size, const char *Name, uptr Flags, 62 MapPlatformData *Data) { 63 DCHECK_EQ(Size % getPageSizeCached(), 0); 64 const bool AllowNoMem = !!(Flags & MAP_ALLOWNOMEM); 65 66 // For MAP_NOACCESS, just allocate a Vmar and return. 67 if (Flags & MAP_NOACCESS) 68 return allocateVmar(Size, Data, AllowNoMem); 69 70 const zx_handle_t Vmar = (Data && Data->Vmar != ZX_HANDLE_INVALID) 71 ? Data->Vmar 72 : _zx_vmar_root_self(); 73 74 zx_status_t Status; 75 zx_handle_t Vmo; 76 uint64_t VmoSize = 0; 77 if (Data && Data->Vmo != ZX_HANDLE_INVALID) { 78 // If a Vmo was specified, it's a resize operation. 79 CHECK(Addr); 80 DCHECK(Flags & MAP_RESIZABLE); 81 Vmo = Data->Vmo; 82 VmoSize = Data->VmoSize; 83 Status = _zx_vmo_set_size(Vmo, VmoSize + Size); 84 if (Status != ZX_OK) { 85 if (Status != ZX_ERR_NO_MEMORY || !AllowNoMem) 86 dieOnError(Status, "zx_vmo_set_size", VmoSize + Size); 87 return nullptr; 88 } 89 } else { 90 // Otherwise, create a Vmo and set its name. 91 Status = _zx_vmo_create(Size, ZX_VMO_RESIZABLE, &Vmo); 92 if (UNLIKELY(Status != ZX_OK)) { 93 if (Status != ZX_ERR_NO_MEMORY || !AllowNoMem) 94 dieOnError(Status, "zx_vmo_create", Size); 95 return nullptr; 96 } 97 _zx_object_set_property(Vmo, ZX_PROP_NAME, Name, strlen(Name)); 98 } 99 100 uintptr_t P; 101 zx_vm_option_t MapFlags = 102 ZX_VM_PERM_READ | ZX_VM_PERM_WRITE | ZX_VM_ALLOW_FAULTS; 103 if (Addr) 104 DCHECK(Data); 105 const uint64_t Offset = 106 Addr ? reinterpret_cast<uintptr_t>(Addr) - Data->VmarBase : 0; 107 if (Offset) 108 MapFlags |= ZX_VM_SPECIFIC; 109 Status = _zx_vmar_map(Vmar, MapFlags, Offset, Vmo, VmoSize, Size, &P); 110 if (UNLIKELY(Status != ZX_OK)) { 111 if (Status != ZX_ERR_NO_MEMORY || !AllowNoMem) 112 dieOnError(Status, "zx_vmar_map", Size); 113 return nullptr; 114 } 115 116 if (Flags & MAP_PRECOMMIT) { 117 Status = _zx_vmar_op_range(Vmar, ZX_VMAR_OP_COMMIT, P, Size, 118 /*buffer=*/nullptr, /*buffer_size=*/0); 119 } 120 121 // No need to track the Vmo if we don't intend on resizing it. Close it. 122 if (Flags & MAP_RESIZABLE) { 123 DCHECK(Data); 124 if (Data->Vmo == ZX_HANDLE_INVALID) 125 Data->Vmo = Vmo; 126 else 127 DCHECK_EQ(Data->Vmo, Vmo); 128 } else { 129 CHECK_EQ(_zx_handle_close(Vmo), ZX_OK); 130 } 131 if (UNLIKELY(Status != ZX_OK)) { 132 if (Status != ZX_ERR_NO_MEMORY || !AllowNoMem) 133 dieOnError(Status, "zx_vmar_op_range", Size); 134 return nullptr; 135 } 136 137 if (Data) 138 Data->VmoSize += Size; 139 140 return reinterpret_cast<void *>(P); 141 } 142 143 void unmap(void *Addr, uptr Size, uptr Flags, MapPlatformData *Data) { 144 if (Flags & UNMAP_ALL) { 145 DCHECK_NE(Data, nullptr); 146 const zx_handle_t Vmar = Data->Vmar; 147 DCHECK_NE(Vmar, _zx_vmar_root_self()); 148 // Destroying the vmar effectively unmaps the whole mapping. 149 CHECK_EQ(_zx_vmar_destroy(Vmar), ZX_OK); 150 CHECK_EQ(_zx_handle_close(Vmar), ZX_OK); 151 } else { 152 const zx_handle_t Vmar = (Data && Data->Vmar != ZX_HANDLE_INVALID) 153 ? Data->Vmar 154 : _zx_vmar_root_self(); 155 const zx_status_t Status = 156 _zx_vmar_unmap(Vmar, reinterpret_cast<uintptr_t>(Addr), Size); 157 if (UNLIKELY(Status != ZX_OK)) 158 dieOnError(Status, "zx_vmar_unmap", Size); 159 } 160 if (Data) { 161 if (Data->Vmo != ZX_HANDLE_INVALID) 162 CHECK_EQ(_zx_handle_close(Data->Vmo), ZX_OK); 163 memset(Data, 0, sizeof(*Data)); 164 } 165 } 166 167 void setMemoryPermission(UNUSED uptr Addr, UNUSED uptr Size, UNUSED uptr Flags, 168 UNUSED MapPlatformData *Data) { 169 const zx_vm_option_t Prot = 170 (Flags & MAP_NOACCESS) ? 0 : (ZX_VM_PERM_READ | ZX_VM_PERM_WRITE); 171 DCHECK(Data); 172 DCHECK_NE(Data->Vmar, ZX_HANDLE_INVALID); 173 const zx_status_t Status = _zx_vmar_protect(Data->Vmar, Prot, Addr, Size); 174 if (Status != ZX_OK) 175 dieOnError(Status, "zx_vmar_protect", Size); 176 } 177 178 void releasePagesToOS(UNUSED uptr BaseAddress, uptr Offset, uptr Size, 179 MapPlatformData *Data) { 180 // TODO: DCHECK the BaseAddress is consistent with the data in 181 // MapPlatformData. 182 DCHECK(Data); 183 DCHECK_NE(Data->Vmar, ZX_HANDLE_INVALID); 184 DCHECK_NE(Data->Vmo, ZX_HANDLE_INVALID); 185 const zx_status_t Status = 186 _zx_vmo_op_range(Data->Vmo, ZX_VMO_OP_DECOMMIT, Offset, Size, NULL, 0); 187 CHECK_EQ(Status, ZX_OK); 188 } 189 190 const char *getEnv(const char *Name) { return getenv(Name); } 191 192 // Note: we need to flag these methods with __TA_NO_THREAD_SAFETY_ANALYSIS 193 // because the Fuchsia implementation of sync_mutex_t has clang thread safety 194 // annotations. Were we to apply proper capability annotations to the top level 195 // HybridMutex class itself, they would not be needed. As it stands, the 196 // thread analysis thinks that we are locking the mutex and accidentally leaving 197 // it locked on the way out. 198 bool HybridMutex::tryLock() __TA_NO_THREAD_SAFETY_ANALYSIS { 199 // Size and alignment must be compatible between both types. 200 return sync_mutex_trylock(&M) == ZX_OK; 201 } 202 203 void HybridMutex::lockSlow() __TA_NO_THREAD_SAFETY_ANALYSIS { 204 sync_mutex_lock(&M); 205 } 206 207 void HybridMutex::unlock() __TA_NO_THREAD_SAFETY_ANALYSIS { 208 sync_mutex_unlock(&M); 209 } 210 211 void HybridMutex::assertHeldImpl() __TA_NO_THREAD_SAFETY_ANALYSIS {} 212 213 u64 getMonotonicTime() { return _zx_clock_get_monotonic(); } 214 u64 getMonotonicTimeFast() { return _zx_clock_get_monotonic(); } 215 216 u32 getNumberOfCPUs() { return _zx_system_get_num_cpus(); } 217 218 u32 getThreadID() { return 0; } 219 220 bool getRandom(void *Buffer, uptr Length, UNUSED bool Blocking) { 221 static_assert(MaxRandomLength <= ZX_CPRNG_DRAW_MAX_LEN, ""); 222 if (UNLIKELY(!Buffer || !Length || Length > MaxRandomLength)) 223 return false; 224 _zx_cprng_draw(Buffer, Length); 225 return true; 226 } 227 228 void outputRaw(const char *Buffer) { 229 __sanitizer_log_write(Buffer, strlen(Buffer)); 230 } 231 232 void setAbortMessage(const char *Message) {} 233 234 } // namespace scudo 235 236 #endif // SCUDO_FUCHSIA 237