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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.
static_assert(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(); }
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
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