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_HANDLE_INVALID) 61 ? Data->Vmar 62 : _zx_vmar_root_self(); 63 64 zx_status_t Status; 65 zx_handle_t Vmo; 66 uint64_t VmoSize = 0; 67 if (Data && Data->Vmo != ZX_HANDLE_INVALID) { 68 // If a Vmo was specified, it's a resize operation. 69 CHECK(Addr); 70 DCHECK(Flags & MAP_RESIZABLE); 71 Vmo = Data->Vmo; 72 VmoSize = Data->VmoSize; 73 Status = _zx_vmo_set_size(Vmo, VmoSize + Size); 74 if (Status != ZX_OK) { 75 if (Status != ZX_ERR_NO_MEMORY || !AllowNoMem) 76 dieOnMapUnmapError(Status == ZX_ERR_NO_MEMORY ? Size : 0); 77 return nullptr; 78 } 79 } else { 80 // Otherwise, create a Vmo and set its name. 81 Status = _zx_vmo_create(Size, ZX_VMO_RESIZABLE, &Vmo); 82 if (UNLIKELY(Status != ZX_OK)) { 83 if (Status != ZX_ERR_NO_MEMORY || !AllowNoMem) 84 dieOnMapUnmapError(Status == ZX_ERR_NO_MEMORY ? Size : 0); 85 return nullptr; 86 } 87 _zx_object_set_property(Vmo, ZX_PROP_NAME, Name, strlen(Name)); 88 } 89 90 uintptr_t P; 91 zx_vm_option_t MapFlags = 92 ZX_VM_PERM_READ | ZX_VM_PERM_WRITE | ZX_VM_ALLOW_FAULTS; 93 if (Addr) 94 DCHECK(Data); 95 const uint64_t Offset = 96 Addr ? reinterpret_cast<uintptr_t>(Addr) - Data->VmarBase : 0; 97 if (Offset) 98 MapFlags |= ZX_VM_SPECIFIC; 99 Status = _zx_vmar_map(Vmar, MapFlags, Offset, Vmo, VmoSize, Size, &P); 100 // No need to track the Vmo if we don't intend on resizing it. Close it. 101 if (Flags & MAP_RESIZABLE) { 102 DCHECK(Data); 103 if (Data->Vmo == ZX_HANDLE_INVALID) 104 Data->Vmo = Vmo; 105 else 106 DCHECK_EQ(Data->Vmo, Vmo); 107 } else { 108 CHECK_EQ(_zx_handle_close(Vmo), ZX_OK); 109 } 110 if (UNLIKELY(Status != ZX_OK)) { 111 if (Status != ZX_ERR_NO_MEMORY || !AllowNoMem) 112 dieOnMapUnmapError(Status == ZX_ERR_NO_MEMORY ? Size : 0); 113 return nullptr; 114 } 115 if (Data) 116 Data->VmoSize += Size; 117 118 return reinterpret_cast<void *>(P); 119 } 120 121 void unmap(void *Addr, uptr Size, uptr Flags, MapPlatformData *Data) { 122 if (Flags & UNMAP_ALL) { 123 DCHECK_NE(Data, nullptr); 124 const zx_handle_t Vmar = Data->Vmar; 125 DCHECK_NE(Vmar, _zx_vmar_root_self()); 126 // Destroying the vmar effectively unmaps the whole mapping. 127 CHECK_EQ(_zx_vmar_destroy(Vmar), ZX_OK); 128 CHECK_EQ(_zx_handle_close(Vmar), ZX_OK); 129 } else { 130 const zx_handle_t Vmar = (Data && Data->Vmar != ZX_HANDLE_INVALID) 131 ? Data->Vmar 132 : _zx_vmar_root_self(); 133 const zx_status_t Status = 134 _zx_vmar_unmap(Vmar, reinterpret_cast<uintptr_t>(Addr), Size); 135 if (UNLIKELY(Status != ZX_OK)) 136 dieOnMapUnmapError(); 137 } 138 if (Data) { 139 if (Data->Vmo != ZX_HANDLE_INVALID) 140 CHECK_EQ(_zx_handle_close(Data->Vmo), ZX_OK); 141 memset(Data, 0, sizeof(*Data)); 142 } 143 } 144 145 void setMemoryPermission(UNUSED uptr Addr, UNUSED uptr Size, UNUSED uptr Flags, 146 UNUSED MapPlatformData *Data) { 147 const zx_vm_option_t Prot = 148 (Flags & MAP_NOACCESS) ? 0 : (ZX_VM_PERM_READ | ZX_VM_PERM_WRITE); 149 DCHECK(Data); 150 DCHECK_NE(Data->Vmar, ZX_HANDLE_INVALID); 151 if (_zx_vmar_protect(Data->Vmar, Prot, Addr, Size) != ZX_OK) 152 dieOnMapUnmapError(); 153 } 154 155 void releasePagesToOS(UNUSED uptr BaseAddress, uptr Offset, uptr Size, 156 MapPlatformData *Data) { 157 DCHECK(Data); 158 DCHECK_NE(Data->Vmar, ZX_HANDLE_INVALID); 159 DCHECK_NE(Data->Vmo, ZX_HANDLE_INVALID); 160 const zx_status_t Status = 161 _zx_vmo_op_range(Data->Vmo, ZX_VMO_OP_DECOMMIT, Offset, Size, NULL, 0); 162 CHECK_EQ(Status, ZX_OK); 163 } 164 165 const char *getEnv(const char *Name) { return getenv(Name); } 166 167 // Note: we need to flag these methods with __TA_NO_THREAD_SAFETY_ANALYSIS 168 // because the Fuchsia implementation of sync_mutex_t has clang thread safety 169 // annotations. Were we to apply proper capability annotations to the top level 170 // HybridMutex class itself, they would not be needed. As it stands, the 171 // thread analysis thinks that we are locking the mutex and accidentally leaving 172 // it locked on the way out. 173 bool HybridMutex::tryLock() __TA_NO_THREAD_SAFETY_ANALYSIS { 174 // Size and alignment must be compatible between both types. 175 return sync_mutex_trylock(&M) == ZX_OK; 176 } 177 178 void HybridMutex::lockSlow() __TA_NO_THREAD_SAFETY_ANALYSIS { 179 sync_mutex_lock(&M); 180 } 181 182 void HybridMutex::unlock() __TA_NO_THREAD_SAFETY_ANALYSIS { 183 sync_mutex_unlock(&M); 184 } 185 186 u64 getMonotonicTime() { return _zx_clock_get_monotonic(); } 187 188 u32 getNumberOfCPUs() { return _zx_system_get_num_cpus(); } 189 190 u32 getThreadID() { return 0; } 191 192 bool getRandom(void *Buffer, uptr Length, UNUSED bool Blocking) { 193 static_assert(MaxRandomLength <= ZX_CPRNG_DRAW_MAX_LEN, ""); 194 if (UNLIKELY(!Buffer || !Length || Length > MaxRandomLength)) 195 return false; 196 _zx_cprng_draw(Buffer, Length); 197 return true; 198 } 199 200 void outputRaw(const char *Buffer) { 201 __sanitizer_log_write(Buffer, strlen(Buffer)); 202 } 203 204 void setAbortMessage(const char *Message) {} 205 206 } // namespace scudo 207 208 #endif // SCUDO_FUCHSIA 209