1/*
2 * Copyright (c) 2015   Author: Oleg Nesterov <oleg@redhat.com>
3 *                      Modify: Li Wang <liwang@redhat.com>
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 <oleg@redhat.com>
31 * 		Date:   Tue Sep 2 19:57:17 2014 +0200
32 *
33 *      commit 66463db4fc5605d51c7bb81d009d5bf30a783a2c
34 *              Author: Oleg Nesterov <oleg@redhat.com>
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
53char *TCID = "signal06";
54int TST_TOTAL = 5;
55
56#if __x86_64__
57
58#define LOOPS 30000
59#define VALUE 123.456
60
61volatile double D;
62volatile int FLAGE;
63
64char altstack[4096 * 10] __attribute__((aligned(4096)));
65
66void test(void)
67{
68	int loop = 0;
69	int pid = getpid();
70
71	D = VALUE;
72	while (D == VALUE && loop < LOOPS) {
73		/* sys_tkill(pid, SIGHUP); asm to avoid save/reload
74		 * fp regs around c call */
75		int unused;
76		asm volatile ("syscall" : "=a"(unused) : "a"(__NR_tkill), "D"(pid), "S"(SIGHUP) : "rcx", "r11");
77
78		loop++;
79	}
80
81	FLAGE = 1;
82	tst_resm(TINFO, "loop = %d", loop);
83
84	if (loop == LOOPS) {
85		tst_resm(TPASS, "%s call succeeded", TCID);
86	} else {
87		tst_resm(TFAIL, "Bug Reproduced!");
88		tst_exit();
89	}
90}
91
92void sigh(int sig LTP_ATTRIBUTE_UNUSED)
93{
94}
95
96void *tfunc(void *arg LTP_ATTRIBUTE_UNUSED)
97{
98	int i;
99
100	for (i = -1; ; i *= -1) {
101		if (i == -1) {
102			TEST(mprotect(altstack, sizeof(altstack), PROT_READ));
103			if (TEST_RETURN == -1)
104				tst_brkm(TBROK | TTERRNO, NULL, "mprotect failed");
105		}
106
107		TEST(mprotect(altstack, sizeof(altstack), PROT_READ | PROT_WRITE));
108		if (TEST_RETURN == -1)
109			tst_brkm(TBROK | TTERRNO, NULL, "mprotect failed");
110
111		if (FLAGE == 1)
112			return NULL;
113	}
114}
115
116int main(int ac, char **av)
117{
118	int i, lc;
119	pthread_t pt;
120
121	tst_parse_opts(ac, av, NULL, NULL);
122
123	stack_t st = {
124		.ss_sp = altstack,
125		.ss_size = sizeof(altstack),
126		.ss_flags = SS_ONSTACK,
127	};
128
129	struct sigaction sa = {
130		.sa_handler = sigh,
131	};
132
133	TEST(sigaction(SIGSEGV, &sa, NULL));
134	if (TEST_RETURN == -1)
135		tst_brkm(TBROK | TTERRNO, NULL,
136				"SIGSEGV signal setup failed");
137	sigaltstack(&st, NULL);
138	sa.sa_flags = SA_ONSTACK;
139
140	TEST(sigaction(SIGHUP, &sa, NULL));
141	if (TEST_RETURN == -1)
142		tst_brkm(TBROK | TTERRNO, NULL,
143				"SIGHUP signal setup failed");
144
145	for (lc = 0; TEST_LOOPING(lc); lc++) {
146		tst_count = 0;
147
148		for (i = 0; i < TST_TOTAL; i++) {
149			FLAGE = 0;
150
151			TEST(pthread_create(&pt, NULL, tfunc, NULL));
152			if (TEST_RETURN)
153				tst_brkm(TBROK | TRERRNO, NULL,
154						"pthread_create failed");
155
156			test();
157
158			TEST(pthread_join(pt, NULL));
159			if (TEST_RETURN)
160				tst_brkm(TBROK | TRERRNO, NULL,
161						"pthread_join failed");
162		}
163	}
164
165	tst_exit();
166}
167
168#else
169int main(void)
170{
171	tst_brkm(TCONF, NULL, "Only test on x86_64.");
172}
173#endif
174