1 | /* Check setcontext on the context from makecontext. |
2 | Copyright (C) 2018-2022 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 <stdio.h> |
20 | #include <stdlib.h> |
21 | #include <ucontext.h> |
22 | #include <unistd.h> |
23 | #include <stdatomic.h> |
24 | |
25 | static ucontext_t ctx[5]; |
26 | static atomic_int done; |
27 | |
28 | static void |
29 | __attribute__((noinline, noclone)) |
30 | f2 (void) |
31 | { |
32 | done++; |
33 | puts (s: "swap contexts in f2" ); |
34 | if (swapcontext (oucp: &ctx[4], ucp: &ctx[2]) != 0) |
35 | { |
36 | printf (format: "%s: setcontext: %m\n" , __FUNCTION__); |
37 | exit (EXIT_FAILURE); |
38 | } |
39 | puts (s: "end f2" ); |
40 | exit (done == 2 ? EXIT_SUCCESS : EXIT_FAILURE); |
41 | } |
42 | |
43 | static void |
44 | f1b (void) |
45 | { |
46 | if (done) |
47 | { |
48 | puts (s: "set context in f1b" ); |
49 | if (setcontext (&ctx[3]) != 0) |
50 | { |
51 | printf (format: "%s: setcontext: %m\n" , __FUNCTION__); |
52 | exit (EXIT_FAILURE); |
53 | } |
54 | } |
55 | exit (EXIT_FAILURE); |
56 | } |
57 | |
58 | static void |
59 | f1a (void) |
60 | { |
61 | static char st2[32768]; |
62 | puts (s: "start f1a" ); |
63 | if (getcontext (ucp: &ctx[2]) != 0) |
64 | { |
65 | printf (format: "%s: getcontext: %m\n" , __FUNCTION__); |
66 | exit (EXIT_FAILURE); |
67 | } |
68 | ctx[2].uc_stack.ss_sp = st2; |
69 | ctx[2].uc_stack.ss_size = sizeof st2; |
70 | ctx[2].uc_link = &ctx[0]; |
71 | makecontext (ucp: &ctx[2], func: (void (*) (void)) f1b, argc: 0); |
72 | f2 (); |
73 | } |
74 | |
75 | /* The execution path through the test looks like this: |
76 | do_test (call) |
77 | -> "making contexts" |
78 | -> "swap contexts" |
79 | f1a (via swapcontext to ctx[1], with alternate stack) |
80 | -> "start f1a" |
81 | f2 (call) |
82 | -> "swap contexts in f2" |
83 | f1b (via swapcontext to ctx[2], with alternate stack) |
84 | -> "set context in f1b" |
85 | do_test (via setcontext to ctx[3], main stack) |
86 | -> "setcontext" |
87 | f2 (via setcontext to ctx[4], with alternate stack) |
88 | -> "end f2" |
89 | |
90 | We must use an alternate stack for f1b, because if we don't then the |
91 | result of executing an earlier caller may overwrite registers |
92 | spilled to the stack in f2. */ |
93 | static int |
94 | do_test (void) |
95 | { |
96 | static char st1[32768]; |
97 | puts (s: "making contexts" ); |
98 | if (getcontext (ucp: &ctx[0]) != 0) |
99 | { |
100 | printf (format: "%s: getcontext: %m\n" , __FUNCTION__); |
101 | exit (EXIT_FAILURE); |
102 | } |
103 | if (getcontext (ucp: &ctx[1]) != 0) |
104 | { |
105 | printf (format: "%s: getcontext: %m\n" , __FUNCTION__); |
106 | exit (EXIT_FAILURE); |
107 | } |
108 | ctx[1].uc_stack.ss_sp = st1; |
109 | ctx[1].uc_stack.ss_size = sizeof st1; |
110 | ctx[1].uc_link = &ctx[0]; |
111 | makecontext (ucp: &ctx[1], func: (void (*) (void)) f1a, argc: 0); |
112 | puts (s: "swap contexts" ); |
113 | if (swapcontext (oucp: &ctx[3], ucp: &ctx[1]) != 0) |
114 | { |
115 | printf (format: "%s: setcontext: %m\n" , __FUNCTION__); |
116 | exit (EXIT_FAILURE); |
117 | } |
118 | if (done != 1) |
119 | exit (EXIT_FAILURE); |
120 | done++; |
121 | puts (s: "set context" ); |
122 | if (setcontext (&ctx[4]) != 0) |
123 | { |
124 | printf (format: "%s: setcontext: %m\n" , __FUNCTION__); |
125 | exit (EXIT_FAILURE); |
126 | } |
127 | exit (EXIT_FAILURE); |
128 | } |
129 | |
130 | #include <support/test-driver.c> |
131 | |