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