| //===-- fuchsia.cpp ---------------------------------------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "platform.h" |
| |
| #if SCUDO_FUCHSIA |
| |
| #include "common.h" |
| #include "mutex.h" |
| #include "string_utils.h" |
| |
| #include <lib/sync/mutex.h> // for sync_mutex_t |
| #include <stdlib.h> // for getenv() |
| #include <zircon/compiler.h> |
| #include <zircon/process.h> |
| #include <zircon/sanitizer.h> |
| #include <zircon/status.h> |
| #include <zircon/syscalls.h> |
| |
| namespace scudo { |
| |
| uptr getPageSize() { return _zx_system_get_page_size(); } |
| |
| void NORETURN die() { __builtin_trap(); } |
| |
| // We zero-initialize the Extra parameter of map(), make sure this is consistent |
| // with ZX_HANDLE_INVALID. |
| static_assert(ZX_HANDLE_INVALID == 0, ""); |
| |
| static void NORETURN dieOnError(zx_status_t Status, const char *FnName, |
| uptr Size) { |
| ScopedString Error; |
| Error.append("SCUDO ERROR: %s failed with size %zuKB (%s)", FnName, |
| Size >> 10, zx_status_get_string(Status)); |
| outputRaw(Error.data()); |
| die(); |
| } |
| |
| static void *allocateVmar(uptr Size, MapPlatformData *Data, bool AllowNoMem) { |
| // Only scenario so far. |
| DCHECK(Data); |
| DCHECK_EQ(Data->Vmar, ZX_HANDLE_INVALID); |
| |
| const zx_status_t Status = _zx_vmar_allocate( |
| _zx_vmar_root_self(), |
| ZX_VM_CAN_MAP_READ | ZX_VM_CAN_MAP_WRITE | ZX_VM_CAN_MAP_SPECIFIC, 0, |
| Size, &Data->Vmar, &Data->VmarBase); |
| if (UNLIKELY(Status != ZX_OK)) { |
| if (Status != ZX_ERR_NO_MEMORY || !AllowNoMem) |
| dieOnError(Status, "zx_vmar_allocate", Size); |
| return nullptr; |
| } |
| return reinterpret_cast<void *>(Data->VmarBase); |
| } |
| |
| void *map(void *Addr, uptr Size, const char *Name, uptr Flags, |
| MapPlatformData *Data) { |
| DCHECK_EQ(Size % getPageSizeCached(), 0); |
| const bool AllowNoMem = !!(Flags & MAP_ALLOWNOMEM); |
| |
| // For MAP_NOACCESS, just allocate a Vmar and return. |
| if (Flags & MAP_NOACCESS) |
| return allocateVmar(Size, Data, AllowNoMem); |
| |
| const zx_handle_t Vmar = (Data && Data->Vmar != ZX_HANDLE_INVALID) |
| ? Data->Vmar |
| : _zx_vmar_root_self(); |
| |
| zx_status_t Status; |
| zx_handle_t Vmo; |
| uint64_t VmoSize = 0; |
| if (Data && Data->Vmo != ZX_HANDLE_INVALID) { |
| // If a Vmo was specified, it's a resize operation. |
| CHECK(Addr); |
| DCHECK(Flags & MAP_RESIZABLE); |
| Vmo = Data->Vmo; |
| VmoSize = Data->VmoSize; |
| Status = _zx_vmo_set_size(Vmo, VmoSize + Size); |
| if (Status != ZX_OK) { |
| if (Status != ZX_ERR_NO_MEMORY || !AllowNoMem) |
| dieOnError(Status, "zx_vmo_set_size", VmoSize + Size); |
| return nullptr; |
| } |
| } else { |
| // Otherwise, create a Vmo and set its name. |
| Status = _zx_vmo_create(Size, ZX_VMO_RESIZABLE, &Vmo); |
| if (UNLIKELY(Status != ZX_OK)) { |
| if (Status != ZX_ERR_NO_MEMORY || !AllowNoMem) |
| dieOnError(Status, "zx_vmo_create", Size); |
| return nullptr; |
| } |
| _zx_object_set_property(Vmo, ZX_PROP_NAME, Name, strlen(Name)); |
| } |
| |
| uintptr_t P; |
| zx_vm_option_t MapFlags = |
| ZX_VM_PERM_READ | ZX_VM_PERM_WRITE | ZX_VM_ALLOW_FAULTS; |
| if (Addr) |
| DCHECK(Data); |
| const uint64_t Offset = |
| Addr ? reinterpret_cast<uintptr_t>(Addr) - Data->VmarBase : 0; |
| if (Offset) |
| MapFlags |= ZX_VM_SPECIFIC; |
| Status = _zx_vmar_map(Vmar, MapFlags, Offset, Vmo, VmoSize, Size, &P); |
| if (UNLIKELY(Status != ZX_OK)) { |
| if (Status != ZX_ERR_NO_MEMORY || !AllowNoMem) |
| dieOnError(Status, "zx_vmar_map", Size); |
| return nullptr; |
| } |
| |
| if (Flags & MAP_PRECOMMIT) { |
| Status = _zx_vmar_op_range(Vmar, ZX_VMAR_OP_COMMIT, P, Size, |
| /*buffer=*/nullptr, /*buffer_size=*/0); |
| } |
| |
| // No need to track the Vmo if we don't intend on resizing it. Close it. |
| if (Flags & MAP_RESIZABLE) { |
| DCHECK(Data); |
| if (Data->Vmo == ZX_HANDLE_INVALID) |
| Data->Vmo = Vmo; |
| else |
| DCHECK_EQ(Data->Vmo, Vmo); |
| } else { |
| CHECK_EQ(_zx_handle_close(Vmo), ZX_OK); |
| } |
| if (UNLIKELY(Status != ZX_OK)) { |
| if (Status != ZX_ERR_NO_MEMORY || !AllowNoMem) |
| dieOnError(Status, "zx_vmar_op_range", Size); |
| return nullptr; |
| } |
| |
| if (Data) |
| Data->VmoSize += Size; |
| |
| return reinterpret_cast<void *>(P); |
| } |
| |
| void unmap(void *Addr, uptr Size, uptr Flags, MapPlatformData *Data) { |
| if (Flags & UNMAP_ALL) { |
| DCHECK_NE(Data, nullptr); |
| const zx_handle_t Vmar = Data->Vmar; |
| DCHECK_NE(Vmar, _zx_vmar_root_self()); |
| // Destroying the vmar effectively unmaps the whole mapping. |
| CHECK_EQ(_zx_vmar_destroy(Vmar), ZX_OK); |
| CHECK_EQ(_zx_handle_close(Vmar), ZX_OK); |
| } else { |
| const zx_handle_t Vmar = (Data && Data->Vmar != ZX_HANDLE_INVALID) |
| ? Data->Vmar |
| : _zx_vmar_root_self(); |
| const zx_status_t Status = |
| _zx_vmar_unmap(Vmar, reinterpret_cast<uintptr_t>(Addr), Size); |
| if (UNLIKELY(Status != ZX_OK)) |
| dieOnError(Status, "zx_vmar_unmap", Size); |
| } |
| if (Data) { |
| if (Data->Vmo != ZX_HANDLE_INVALID) |
| CHECK_EQ(_zx_handle_close(Data->Vmo), ZX_OK); |
| memset(Data, 0, sizeof(*Data)); |
| } |
| } |
| |
| void setMemoryPermission(UNUSED uptr Addr, UNUSED uptr Size, UNUSED uptr Flags, |
| UNUSED MapPlatformData *Data) { |
| const zx_vm_option_t Prot = |
| (Flags & MAP_NOACCESS) ? 0 : (ZX_VM_PERM_READ | ZX_VM_PERM_WRITE); |
| DCHECK(Data); |
| DCHECK_NE(Data->Vmar, ZX_HANDLE_INVALID); |
| const zx_status_t Status = _zx_vmar_protect(Data->Vmar, Prot, Addr, Size); |
| if (Status != ZX_OK) |
| dieOnError(Status, "zx_vmar_protect", Size); |
| } |
| |
| void releasePagesToOS(UNUSED uptr BaseAddress, uptr Offset, uptr Size, |
| MapPlatformData *Data) { |
| // TODO: DCHECK the BaseAddress is consistent with the data in |
| // MapPlatformData. |
| DCHECK(Data); |
| DCHECK_NE(Data->Vmar, ZX_HANDLE_INVALID); |
| DCHECK_NE(Data->Vmo, ZX_HANDLE_INVALID); |
| const zx_status_t Status = |
| _zx_vmo_op_range(Data->Vmo, ZX_VMO_OP_DECOMMIT, Offset, Size, NULL, 0); |
| CHECK_EQ(Status, ZX_OK); |
| } |
| |
| const char *getEnv(const char *Name) { return getenv(Name); } |
| |
| // Note: we need to flag these methods with __TA_NO_THREAD_SAFETY_ANALYSIS |
| // because the Fuchsia implementation of sync_mutex_t has clang thread safety |
| // annotations. Were we to apply proper capability annotations to the top level |
| // HybridMutex class itself, they would not be needed. As it stands, the |
| // thread analysis thinks that we are locking the mutex and accidentally leaving |
| // it locked on the way out. |
| bool HybridMutex::tryLock() __TA_NO_THREAD_SAFETY_ANALYSIS { |
| // Size and alignment must be compatible between both types. |
| return sync_mutex_trylock(&M) == ZX_OK; |
| } |
| |
| void HybridMutex::lockSlow() __TA_NO_THREAD_SAFETY_ANALYSIS { |
| sync_mutex_lock(&M); |
| } |
| |
| void HybridMutex::unlock() __TA_NO_THREAD_SAFETY_ANALYSIS { |
| sync_mutex_unlock(&M); |
| } |
| |
| void HybridMutex::assertHeldImpl() __TA_NO_THREAD_SAFETY_ANALYSIS {} |
| |
| u64 getMonotonicTime() { return _zx_clock_get_monotonic(); } |
| u64 getMonotonicTimeFast() { return _zx_clock_get_monotonic(); } |
| |
| u32 getNumberOfCPUs() { return _zx_system_get_num_cpus(); } |
| |
| u32 getThreadID() { return 0; } |
| |
| bool getRandom(void *Buffer, uptr Length, UNUSED bool Blocking) { |
| static_assert(MaxRandomLength <= ZX_CPRNG_DRAW_MAX_LEN, ""); |
| if (UNLIKELY(!Buffer || !Length || Length > MaxRandomLength)) |
| return false; |
| _zx_cprng_draw(Buffer, Length); |
| return true; |
| } |
| |
| void outputRaw(const char *Buffer) { |
| __sanitizer_log_write(Buffer, strlen(Buffer)); |
| } |
| |
| void setAbortMessage(const char *Message) {} |
| |
| } // namespace scudo |
| |
| #endif // SCUDO_FUCHSIA |