1 /*
2 * Copyright (c) 2015 Author: Oleg Nesterov <[email protected]>
3 * Modify: Li Wang <[email protected]>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of version 2 of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
12 *
13 * you should have received a copy of the GNU General Public License along
14 * with this program; if not, write the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 /*
19 * Description:
20 *
21 * save_xstate_sig()->drop_init_fpu() doesn't look right. setup_rt_frame()
22 * can fail after that, in this case the next setup_rt_frame() triggered
23 * by SIGSEGV won't save fpu simply because the old state was lost. This
24 * obviously mean that fpu won't be restored after sys_rt_sigreturn() from
25 * SIGSEGV handler.
26 *
27 * These commits fix the issue on v3.17-rc3-3 stable kernel:
28 *
29 * commit df24fb859a4e200d9324e2974229fbb7adf00aef
30 * Author: Oleg Nesterov <[email protected]>
31 * Date: Tue Sep 2 19:57:17 2014 +0200
32 *
33 * commit 66463db4fc5605d51c7bb81d009d5bf30a783a2c
34 * Author: Oleg Nesterov <[email protected]>
35 * Date: Tue Sep 2 19:57:13 2014 +0200
36 *
37 * Reproduce:
38 * Test-case (needs -O2).
39 */
40
41 #include <stdio.h>
42 #include <signal.h>
43 #include <unistd.h>
44 #include <sys/syscall.h>
45 #include <sys/mman.h>
46 #include <pthread.h>
47 #include <assert.h>
48 #include <errno.h>
49
50 #include "test.h"
51 #include "lapi/syscalls.h"
52 #include "pgsize_helpers.h"
53
54 char *TCID = "signal06";
55 int TST_TOTAL = 5;
56
57 #if __x86_64__
58
59 #define LOOPS 30000
60 #define VALUE 123.456
61
62 volatile double D;
63 volatile int FLAGE;
64
65 char altstack[MAX_PAGE_SIZE * 10] __attribute__((aligned(MAX_PAGE_SIZE)));
66
test(void)67 void test(void)
68 {
69 int loop = 0;
70 int pid = getpid();
71
72 D = VALUE;
73 while (D == VALUE && loop < LOOPS) {
74 /* sys_tkill(pid, SIGHUP); asm to avoid save/reload
75 * fp regs around c call */
76 int unused;
77 asm volatile ("syscall" : "=a"(unused) : "a"(__NR_tkill), "D"(pid), "S"(SIGHUP) : "rcx", "r11");
78
79 loop++;
80 }
81
82 FLAGE = 1;
83 tst_resm(TINFO, "loop = %d", loop);
84
85 if (loop == LOOPS) {
86 tst_resm(TPASS, "%s call succeeded", TCID);
87 } else {
88 tst_resm(TFAIL, "Bug Reproduced!");
89 tst_exit();
90 }
91 }
92
sigh(int sig LTP_ATTRIBUTE_UNUSED)93 void sigh(int sig LTP_ATTRIBUTE_UNUSED)
94 {
95 }
96
tfunc(void * arg LTP_ATTRIBUTE_UNUSED)97 void *tfunc(void *arg LTP_ATTRIBUTE_UNUSED)
98 {
99 int i;
100
101 for (i = -1; ; i *= -1) {
102 if (i == -1) {
103 TEST(mprotect(altstack, sizeof(altstack), PROT_READ));
104 if (TEST_RETURN == -1)
105 tst_brkm(TBROK | TTERRNO, NULL, "mprotect failed");
106 }
107
108 TEST(mprotect(altstack, sizeof(altstack), PROT_READ | PROT_WRITE));
109 if (TEST_RETURN == -1)
110 tst_brkm(TBROK | TTERRNO, NULL, "mprotect failed");
111
112 if (FLAGE == 1)
113 return NULL;
114 }
115 }
116
main(int ac,char ** av)117 int main(int ac, char **av)
118 {
119 int i, lc;
120 pthread_t pt;
121
122 tst_parse_opts(ac, av, NULL, NULL);
123
124 stack_t st = {
125 .ss_sp = altstack,
126 .ss_size = sizeof(altstack),
127 .ss_flags = SS_ONSTACK,
128 };
129
130 struct sigaction sa = {
131 .sa_handler = sigh,
132 };
133
134 TEST(sigaction(SIGSEGV, &sa, NULL));
135 if (TEST_RETURN == -1)
136 tst_brkm(TBROK | TTERRNO, NULL,
137 "SIGSEGV signal setup failed");
138 sigaltstack(&st, NULL);
139 sa.sa_flags = SA_ONSTACK;
140
141 TEST(sigaction(SIGHUP, &sa, NULL));
142 if (TEST_RETURN == -1)
143 tst_brkm(TBROK | TTERRNO, NULL,
144 "SIGHUP signal setup failed");
145
146 for (lc = 0; TEST_LOOPING(lc); lc++) {
147 tst_count = 0;
148
149 for (i = 0; i < TST_TOTAL; i++) {
150 FLAGE = 0;
151
152 TEST(pthread_create(&pt, NULL, tfunc, NULL));
153 if (TEST_RETURN)
154 tst_brkm(TBROK | TRERRNO, NULL,
155 "pthread_create failed");
156
157 test();
158
159 TEST(pthread_join(pt, NULL));
160 if (TEST_RETURN)
161 tst_brkm(TBROK | TRERRNO, NULL,
162 "pthread_join failed");
163 }
164 }
165
166 tst_exit();
167 }
168
169 #else
main(void)170 int main(void)
171 {
172 tst_brkm(TCONF, NULL, "Only test on x86_64.");
173 }
174 #endif
175