blob: e3b210b34ab2b56bc1d8ea5387c0b65bd88eeaeb [file] [log] [blame]
// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "syscall-entry.h"
#include "zircon-syscall-arm64.S"
#include <lib/syscalls/zx-syscall-numbers.h>
.cfi_sections .eh_frame, .debug_frame
// (value_ptr: x0, wake_count: w1, new_value: w2, handle: w3)
syscall_entry_begin zx_futex_wake_handle_close_thread_exit
// Store the value into the futex, which should signal that the stack is no longer in use.
// atomic_store_explicit(value_ptr, new_value, memory_order_release)
stlr w2, [x0]
// Now the stack might be gone and we can never return!
// Save the handle argument in a callee-saves register (x19).
// Since this function cannot return, do not bother preserving the old contents.
mov w19, w3
zircon_syscall ZX_SYS_futex_wake, zx_futex_wake, zx_futex_wake_handle_close_thread_exit
cbnz x0, .Lfutex_wake_fail
mov w0, w19
zircon_syscall ZX_SYS_handle_close, zx_handle_close, zx_futex_wake_handle_close_thread_exit
cbnz x0, .Lhandle_close_fail
zircon_syscall ZX_SYS_thread_exit, zx_thread_exit, zx_futex_wake_handle_close_thread_exit
// It should be impossible to get here.
brk #1000
// We can't recover in these cases, since our stack may have been freed.
brk #1000
brk #1000
syscall_entry_end zx_futex_wake_handle_close_thread_exit