| // Copyright 2023 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-riscv64.S" |
| #include <lib/syscalls/zx-syscall-numbers.h> |
| |
| .text |
| |
| .cfi_sections .eh_frame, .debug_frame |
| |
| // (vmar_handle: a0, addr: a1, len: a2, handle: a3) |
| syscall_entry_begin zx_vmar_unmap_handle_close_thread_exit |
| |
| // Save the handle argument in a callee-saves register (s1). |
| // Callee-save that register so we can unwind in the error case. |
| // We only need to save s1, but we have to keep SP aligned to 16 |
| // bytes, so we always push and pop registers in pairs. |
| add sp, sp, -16 |
| .cfi_adjust_cfa_offset 16 |
| sd s1, (sp) |
| .cfi_offset s1, -16 |
| mv s1, a3 |
| |
| zircon_syscall ZX_SYS_vmar_unmap, zx_vmar_unmap, zx_vmar_unmap_handle_close_thread_exit |
| bnez a0, .Lvmar_unmap_fail |
| |
| // Now the stack is gone and we can never return! |
| |
| mv a0, s1 |
| zircon_syscall ZX_SYS_handle_close, zx_handle_close, zx_vmar_unmap_handle_close_thread_exit |
| bnez a0, .Lhandle_close_fail |
| |
| zircon_syscall ZX_SYS_thread_exit, zx_thread_exit, zx_vmar_unmap_handle_close_thread_exit |
| |
| // It should be impossible to get here. |
| .Lthread_exit_returned: |
| unimp |
| |
| .Lvmar_unmap_fail: |
| ld s1, (sp) |
| .cfi_same_value s1 |
| add sp, sp, 16 |
| .cfi_adjust_cfa_offset -16 |
| ret |
| |
| .Lhandle_close_fail: |
| unimp |
| |
| syscall_entry_end zx_vmar_unmap_handle_close_thread_exit |
