1/* Check multiple makecontext calls.
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
23static ucontext_t uctx_main, uctx_func1, uctx_func2;
24const char *str1 = "\e[31mswapcontext(&uctx_func1, &uctx_main)\e[0m";
25const char *str2 = "\e[34mswapcontext(&uctx_func2, &uctx_main)\e[0m";
26const char *fmt1 = "\e[31m";
27const char *fmt2 = "\e[34m";
28
29#define handle_error(msg) \
30 do { perror(msg); exit(EXIT_FAILURE); } while (0)
31
32__attribute__((noinline, noclone))
33static void
34func4(ucontext_t *uocp, ucontext_t *ucp, const char *str, const char *fmt)
35{
36 printf(format: " %sfunc4: %s\e[0m\n", fmt, str);
37 if (swapcontext(oucp: uocp, ucp: ucp) == -1)
38 handle_error("swapcontext");
39 printf(format: " %sfunc4: returning\e[0m\n", fmt);
40}
41
42__attribute__((noinline, noclone))
43static void
44func3(ucontext_t *uocp, ucontext_t *ucp, const char *str, const char *fmt)
45{
46 printf(format: " %sfunc3: func4(uocp, ucp, str)\e[0m\n", fmt);
47 func4(uocp, ucp, str, fmt);
48 printf(format: " %sfunc3: returning\e[0m\n", fmt);
49}
50
51__attribute__((noinline, noclone))
52static void
53func1(void)
54{
55 while ( 1 )
56 {
57 printf(format: " \e[31mfunc1: func3(&uctx_func1, &uctx_main, str1)\e[0m\n");
58 func3( uocp: &uctx_func1, ucp: &uctx_main, str: str1, fmt: fmt1);
59 }
60}
61
62__attribute__((noinline, noclone))
63static void
64func2(void)
65{
66 while ( 1 )
67 {
68 printf(format: " \e[34mfunc2: func3(&uctx_func2, &uctx_main, str2)\e[0m\n");
69 func3(uocp: &uctx_func2, ucp: &uctx_main, str: str2, fmt: fmt2);
70 }
71}
72
73static int
74do_test (void)
75{
76 char func1_stack[16384];
77 char func2_stack[16384];
78 int i;
79
80 if (getcontext(ucp: &uctx_func1) == -1)
81 handle_error("getcontext");
82 uctx_func1.uc_stack.ss_sp = func1_stack;
83 uctx_func1.uc_stack.ss_size = sizeof (func1_stack);
84 uctx_func1.uc_link = &uctx_main;
85 makecontext(ucp: &uctx_func1, func: func1, argc: 0);
86
87 if (getcontext(ucp: &uctx_func2) == -1)
88 handle_error("getcontext");
89 uctx_func2.uc_stack.ss_sp = func2_stack;
90 uctx_func2.uc_stack.ss_size = sizeof (func2_stack);
91 uctx_func2.uc_link = &uctx_func1;
92 makecontext(ucp: &uctx_func2, func: func2, argc: 0);
93
94 for ( i = 0; i < 4; i++ )
95 {
96 if (swapcontext(oucp: &uctx_main, ucp: &uctx_func1) == -1)
97 handle_error("swapcontext");
98 printf(format: " \e[35mmain: swapcontext(&uctx_main, &uctx_func2)\n\e[0m");
99 if (swapcontext(oucp: &uctx_main, ucp: &uctx_func2) == -1)
100 handle_error("swapcontext");
101 printf(format: " \e[35mmain: swapcontext(&uctx_main, &uctx_func1)\n\e[0m");
102 }
103
104 printf(format: "main: exiting\n");
105 exit(EXIT_SUCCESS);
106}
107
108#include <support/test-driver.c>
109

source code of glibc/stdlib/tst-swapcontext1.c