1 /*
 2  * Copyright (c) 2022, 2026, Oracle and/or its affiliates. All rights reserved.
 3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 4  *
 5  * This code is free software; you can redistribute it and/or modify it
 6  * under the terms of the GNU General Public License version 2 only, as
 7  * published by the Free Software Foundation.
 8  *
 9  * This code is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * version 2 for more details (a copy is included in the LICENSE file that
13  * accompanied this code).
14  *
15  * You should have received a copy of the GNU General Public License version
16  * 2 along with this work; if not, write to the Free Software Foundation,
17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18  *
19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20  * or visit www.oracle.com if you need additional information or have any
21  * questions.
22  */
23 
24 #include "downcallLinker.hpp"
25 #include "runtime/interfaceSupport.inline.hpp"
26 
27 #include <cerrno>
28 #ifdef _WIN64
29 #include <Windows.h>
30 #include <Winsock2.h>
31 #endif
32 
33 // keep in synch with jdk.internal.foreign.abi.CapturableState
34 enum PreservableValues {
35   GET_LAST_ERROR      = 1 << 0,
36   WSA_GET_LAST_ERROR  = 1 << 1,
37   ERRNO               = 1 << 2
38 };
39 
40 // We call this from _thread_in_native, right before a downcall
41 JVM_LEAF(void, DowncallLinker::capture_state_pre(int32_t* value_ptr, int captured_state_mask))
42 #ifdef _WIN64
43   if (captured_state_mask & GET_LAST_ERROR) {
44     SetLastError(*value_ptr);
45   }
46   value_ptr++;
47   if (captured_state_mask & WSA_GET_LAST_ERROR) {
48     WSASetLastError(*value_ptr);
49     *value_ptr = WSAGetLastError();
50   }
51   value_ptr++;
52 #endif
53   if (captured_state_mask & ERRNO) {
54     errno = *value_ptr;
55   }
56 JVM_END
57 
58 // We call this from _thread_in_native, right after a downcall
59 JVM_LEAF(void, DowncallLinker::capture_state_post(int32_t* value_ptr, int captured_state_mask))
60 #ifdef _WIN64
61   if (captured_state_mask & GET_LAST_ERROR) {
62     *value_ptr = GetLastError();
63   }
64   value_ptr++;
65   if (captured_state_mask & WSA_GET_LAST_ERROR) {
66     *value_ptr = WSAGetLastError();
67   }
68   value_ptr++;
69 #endif
70   if (captured_state_mask & ERRNO) {
71     *value_ptr = errno;
72   }
73 JVM_END
74 
75 void DowncallLinker::StubGenerator::add_offsets_to_oops(GrowableArray<VMStorage>& java_regs, VMStorage tmp1, VMStorage tmp2) const {
76   int reg_idx = 0;
77   for (int sig_idx = 0; sig_idx < _num_args; sig_idx++) {
78     if (_signature[sig_idx] == T_OBJECT) {
79       assert(_signature[sig_idx + 1] == T_LONG, "expected offset after oop");
80       VMStorage reg_oop = java_regs.at(reg_idx++);
81       VMStorage reg_offset = java_regs.at(reg_idx++);
82       sig_idx++; // skip offset
83       pd_add_offset_to_oop(reg_oop, reg_offset, tmp1, tmp2);
84     } else if (_signature[sig_idx] != T_VOID) {
85       reg_idx++;
86     }
87   }
88 }