1/* Check setjmp/longjmp within user context.
2 Copyright (C) 2023-2024 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <errno.h>
20#include <stdio.h>
21#include <stdlib.h>
22#include <string.h>
23#include <setjmp.h>
24#include <ucontext.h>
25#include <unistd.h>
26
27static ucontext_t ctx[3];
28static jmp_buf jmpbuf;
29
30static int was_in_f1;
31static int was_in_f2;
32static int longjmp_called;
33
34static char st2[32768];
35
36static void
37f1 (int a0, int a1, int a2, int a3)
38{
39 printf (format: "start f1(a0=%x,a1=%x,a2=%x,a3=%x)\n", a0, a1, a2, a3);
40
41 if (a0 != 1 || a1 != 2 || a2 != 3 || a3 != -4)
42 {
43 puts (s: "arg mismatch");
44 exit (EXIT_FAILURE);
45 }
46
47 if (swapcontext (oucp: &ctx[1], ucp: &ctx[2]) != 0)
48 {
49 printf (format: "%s: swapcontext: %m\n", __FUNCTION__);
50 exit (EXIT_FAILURE);
51 }
52 puts (s: "finish f1");
53 was_in_f1 = 1;
54}
55
56static void
57__attribute__ ((noinline, noclone))
58call_longjmp (void)
59{
60 longjmp_called = 1;
61 longjmp (jmpbuf, 1);
62}
63
64static void
65f2 (void)
66{
67 if (!longjmp_called)
68 {
69 if (setjmp (jmpbuf) == 0)
70 call_longjmp ();
71 }
72
73 puts (s: "start f2");
74 if (swapcontext (oucp: &ctx[2], ucp: &ctx[1]) != 0)
75 {
76 printf (format: "%s: swapcontext: %m\n", __FUNCTION__);
77 exit (EXIT_FAILURE);
78 }
79 puts (s: "finish f2");
80 was_in_f2 = 1;
81}
82
83volatile int global;
84static int back_in_main;
85
86static void
87check_called (void)
88{
89 if (back_in_main == 0)
90 {
91 puts (s: "program did not reach main again");
92 _exit (EXIT_FAILURE);
93 }
94}
95
96static int
97do_test (void)
98{
99 atexit (func: check_called);
100
101 char st1[32768];
102
103 puts (s: "making contexts");
104 if (getcontext (ucp: &ctx[1]) != 0)
105 {
106 if (errno == ENOSYS)
107 {
108 back_in_main = 1;
109 exit (EXIT_SUCCESS);
110 }
111
112 printf (format: "%s: getcontext: %m\n", __FUNCTION__);
113 exit (EXIT_FAILURE);
114 }
115
116 /* Play some tricks with this context. */
117 if (++global == 1)
118 if (setcontext (&ctx[1]) != 0)
119 {
120 printf (format: "%s: setcontext: %m\n", __FUNCTION__);
121 exit (EXIT_FAILURE);
122 }
123 if (global != 2)
124 {
125 printf (format: "%s: 'global' not incremented twice\n", __FUNCTION__);
126 exit (EXIT_FAILURE);
127 }
128
129 ctx[1].uc_stack.ss_sp = st1;
130 ctx[1].uc_stack.ss_size = sizeof st1;
131 ctx[1].uc_link = &ctx[0];
132 {
133 ucontext_t tempctx = ctx[1];
134 makecontext (ucp: &ctx[1], func: (void (*) (void)) f1, argc: 4, 1, 2, 3, -4);
135
136 /* Without this check, a stub makecontext can make us spin forever. */
137 if (memcmp (&tempctx, &ctx[1], sizeof ctx[1]) == 0)
138 {
139 puts (s: "makecontext was a no-op, presuming not implemented");
140 return 0;
141 }
142 }
143
144 if (getcontext (ucp: &ctx[2]) != 0)
145 {
146 printf (format: "%s: second getcontext: %m\n", __FUNCTION__);
147 exit (EXIT_FAILURE);
148 }
149 ctx[2].uc_stack.ss_sp = st2;
150 ctx[2].uc_stack.ss_size = sizeof st2;
151 ctx[2].uc_link = &ctx[1];
152 makecontext (ucp: &ctx[2], func: f2, argc: 0);
153
154 puts (s: "swapping contexts");
155 if (swapcontext (oucp: &ctx[0], ucp: &ctx[2]) != 0)
156 {
157 printf (format: "%s: swapcontext: %m\n", __FUNCTION__);
158 exit (EXIT_FAILURE);
159 }
160 puts (s: "back at main program");
161 back_in_main = 1;
162
163 if (was_in_f1 == 0)
164 {
165 puts (s: "didn't reach f1");
166 exit (EXIT_FAILURE);
167 }
168 if (was_in_f2 == 0)
169 {
170 puts (s: "didn't reach f2");
171 exit (EXIT_FAILURE);
172 }
173
174 puts (s: "test succeeded");
175 return 0;
176}
177
178#include <support/test-driver.c>
179

source code of glibc/stdlib/tst-setcontext11.c