diff options
Diffstat (limited to 'lib/scudo/standalone/fuchsia.cpp')
-rw-r--r-- | lib/scudo/standalone/fuchsia.cpp | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/lib/scudo/standalone/fuchsia.cpp b/lib/scudo/standalone/fuchsia.cpp new file mode 100644 index 000000000000..0a9483ae1dd0 --- /dev/null +++ b/lib/scudo/standalone/fuchsia.cpp @@ -0,0 +1,189 @@ +//===-- 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 <limits.h> // for PAGE_SIZE +#include <stdlib.h> // for getenv() +#include <zircon/compiler.h> +#include <zircon/sanitizer.h> +#include <zircon/syscalls.h> + +namespace scudo { + +uptr getPageSize() { return PAGE_SIZE; } + +void NORETURN die() { __builtin_trap(); } + +// We zero-initialize the Extra parameter of map(), make sure this is consistent +// with ZX_HANDLE_INVALID. +COMPILER_CHECK(ZX_HANDLE_INVALID == 0); + +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) + dieOnMapUnmapError(Status == ZX_ERR_NO_MEMORY); + return nullptr; + } + return reinterpret_cast<void *>(Data->VmarBase); +} + +void *map(void *Addr, uptr Size, const char *Name, uptr Flags, + MapPlatformData *Data) { + DCHECK_EQ(Size % PAGE_SIZE, 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_vmar_root_self(); + CHECK_NE(Vmar, ZX_HANDLE_INVALID); + + 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) + dieOnMapUnmapError(Status == ZX_ERR_NO_MEMORY); + 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) + dieOnMapUnmapError(Status == ZX_ERR_NO_MEMORY); + 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; + 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); + // No need to track the Vmo if we don't intend on resizing it. Close it. + if (Flags & MAP_RESIZABLE) { + DCHECK(Data); + DCHECK_EQ(Data->Vmo, ZX_HANDLE_INVALID); + Data->Vmo = Vmo; + } else { + CHECK_EQ(_zx_handle_close(Vmo), ZX_OK); + } + if (UNLIKELY(Status != ZX_OK)) { + if (Status != ZX_ERR_NO_MEMORY || !AllowNoMem) + dieOnMapUnmapError(Status == ZX_ERR_NO_MEMORY); + 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_vmar_root_self(); + const zx_status_t Status = + _zx_vmar_unmap(Vmar, reinterpret_cast<uintptr_t>(Addr), Size); + if (UNLIKELY(Status != ZX_OK)) + dieOnMapUnmapError(); + } + if (Data) { + if (Data->Vmo != ZX_HANDLE_INVALID) + CHECK_EQ(_zx_handle_close(Data->Vmo), ZX_OK); + memset(Data, 0, sizeof(*Data)); + } +} + +void releasePagesToOS(UNUSED uptr BaseAddress, uptr Offset, uptr Size, + MapPlatformData *Data) { + 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); +} + +u64 getMonotonicTime() { return _zx_clock_get_monotonic(); } + +u32 getNumberOfCPUs() { return _zx_system_get_num_cpus(); } + +bool getRandom(void *Buffer, uptr Length, UNUSED bool Blocking) { + COMPILER_CHECK(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 |