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-rw-r--r--lib/scudo/standalone/fuchsia.cpp189
1 files changed, 189 insertions, 0 deletions
diff --git a/lib/scudo/standalone/fuchsia.cpp b/lib/scudo/standalone/fuchsia.cpp
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+//===-- 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