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