1 /*
2  * Copyright (C) 2018 The Android Open Source Project
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 
30 #include <signal.h>
31 #include <sys/syscall.h>
32 
33 #include <functional>
34 
35 #include <gtest/gtest.h>
36 
37 #include "sigchain.h"
38 
39 #if !defined(__BIONIC__)
40 typedef sigset_t sigset64_t;
41 
sigemptyset64(sigset64_t * set)42 static int sigemptyset64(sigset64_t* set) {
43   return sigemptyset(set);
44 }
45 
sigismember64(sigset64_t * set,int member)46 static int sigismember64(sigset64_t* set, int member) {
47   return sigismember(set, member);
48 }
49 #endif
50 
RealSigprocmask(int how,const sigset64_t * new_sigset,sigset64_t * old_sigset)51 static int RealSigprocmask(int how, const sigset64_t* new_sigset, sigset64_t* old_sigset) {
52   // glibc's sigset_t is overly large, so sizeof(*new_sigset) doesn't work.
53   return syscall(__NR_rt_sigprocmask, how, new_sigset, old_sigset, 8);
54 }
55 
56 class SigchainTest : public ::testing::Test {
SetUp()57   void SetUp() final {
58     art::AddSpecialSignalHandlerFn(SIGSEGV, &action);
59   }
60 
TearDown()61   void TearDown() final {
62     art::RemoveSpecialSignalHandlerFn(SIGSEGV, action.sc_sigaction);
63   }
64 
65   art::SigchainAction action = {
__anonbddd807a0102() 66       .sc_sigaction = [](int, siginfo_t*, void*) { return true; },
__anonbddd807a0202() 67       .sc_mask = {},
68       .sc_flags = 0,
69   };
70 };
71 
72 
TestSignalBlocking(std::function<void ()> fn)73 static void TestSignalBlocking(std::function<void()> fn) {
74   // Unblock SIGSEGV, make sure it stays unblocked.
75   sigset64_t mask;
76   sigemptyset64(&mask);
77   ASSERT_EQ(0, RealSigprocmask(SIG_SETMASK, &mask, nullptr)) << strerror(errno);
78 
79   fn();
80 
81   if (testing::Test::HasFatalFailure()) return;
82   ASSERT_EQ(0, RealSigprocmask(SIG_SETMASK, nullptr, &mask));
83   ASSERT_FALSE(sigismember64(&mask, SIGSEGV));
84 }
85 
TEST_F(SigchainTest,sigprocmask_setmask)86 TEST_F(SigchainTest, sigprocmask_setmask) {
87   TestSignalBlocking([]() {
88     sigset_t mask;
89     sigfillset(&mask);
90     ASSERT_EQ(0, sigprocmask(SIG_SETMASK, &mask, nullptr));
91   });
92 }
93 
TEST_F(SigchainTest,sigprocmask_block)94 TEST_F(SigchainTest, sigprocmask_block) {
95   TestSignalBlocking([]() {
96     sigset_t mask;
97     sigfillset(&mask);
98     ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &mask, nullptr));
99   });
100 }
101 
102 // bionic-only wide variants for LP32.
103 #if defined(__BIONIC__)
TEST_F(SigchainTest,sigprocmask64_setmask)104 TEST_F(SigchainTest, sigprocmask64_setmask) {
105   TestSignalBlocking([]() {
106     sigset64_t mask;
107     sigfillset64(&mask);
108     ASSERT_EQ(0, sigprocmask64(SIG_SETMASK, &mask, nullptr));
109   });
110 }
111 
TEST_F(SigchainTest,sigprocmask64_block)112 TEST_F(SigchainTest, sigprocmask64_block) {
113   TestSignalBlocking([]() {
114     sigset64_t mask;
115     sigfillset64(&mask);
116     ASSERT_EQ(0, sigprocmask64(SIG_BLOCK, &mask, nullptr));
117   });
118 }
119 
TEST_F(SigchainTest,pthread_sigmask64_setmask)120 TEST_F(SigchainTest, pthread_sigmask64_setmask) {
121   TestSignalBlocking([]() {
122     sigset64_t mask;
123     sigfillset64(&mask);
124     ASSERT_EQ(0, pthread_sigmask64(SIG_SETMASK, &mask, nullptr));
125   });
126 }
127 
TEST_F(SigchainTest,pthread_sigmask64_block)128 TEST_F(SigchainTest, pthread_sigmask64_block) {
129   TestSignalBlocking([]() {
130     sigset64_t mask;
131     sigfillset64(&mask);
132     ASSERT_EQ(0, pthread_sigmask64(SIG_BLOCK, &mask, nullptr));
133   });
134 }
135 #endif
136 
137 // glibc doesn't implement most of these in terms of sigprocmask, which we rely on.
138 #if defined(__BIONIC__)
TEST_F(SigchainTest,pthread_sigmask_setmask)139 TEST_F(SigchainTest, pthread_sigmask_setmask) {
140   TestSignalBlocking([]() {
141     sigset_t mask;
142     sigfillset(&mask);
143     ASSERT_EQ(0, pthread_sigmask(SIG_SETMASK, &mask, nullptr));
144   });
145 }
146 
TEST_F(SigchainTest,pthread_sigmask_block)147 TEST_F(SigchainTest, pthread_sigmask_block) {
148   TestSignalBlocking([]() {
149     sigset_t mask;
150     sigfillset(&mask);
151     ASSERT_EQ(0, pthread_sigmask(SIG_BLOCK, &mask, nullptr));
152   });
153 }
154 
TEST_F(SigchainTest,sigset_mask)155 TEST_F(SigchainTest, sigset_mask) {
156   TestSignalBlocking([]() {
157     sigset(SIGSEGV, SIG_HOLD);
158   });
159 }
160 
TEST_F(SigchainTest,sighold)161 TEST_F(SigchainTest, sighold) {
162   TestSignalBlocking([]() {
163     sighold(SIGSEGV);
164   });
165 }
166 
167 #if defined(__BIONIC__)
168 // Not exposed via headers, but the symbols are available if you declare them yourself.
169 extern "C" int sigblock(int);
170 extern "C" int sigsetmask(int);
171 #endif
172 
TEST_F(SigchainTest,sigblock)173 TEST_F(SigchainTest, sigblock) {
174   TestSignalBlocking([]() {
175     int mask = ~0U;
176     ASSERT_EQ(0, sigblock(mask));
177   });
178 }
179 
TEST_F(SigchainTest,sigsetmask)180 TEST_F(SigchainTest, sigsetmask) {
181   TestSignalBlocking([]() {
182     int mask = ~0U;
183     ASSERT_EQ(0, sigsetmask(mask));
184   });
185 }
186 
187 #endif
188