1 | /* Check setjmp/longjmp between user contexts. |
2 | Copyright (C) 2023 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 <setjmp.h> |
22 | #include <ucontext.h> |
23 | #include <stackinfo.h> |
24 | |
25 | static ucontext_t uctx_main, uctx_func1, uctx_func2; |
26 | const char *str1 = "\e[31mswapcontext(&uctx_func1, &uctx_main)\e[0m" ; |
27 | const char *str2 = "\e[34mswapcontext(&uctx_func2, &uctx_main)\e[0m" ; |
28 | const char *fmt1 = "\e[31m" ; |
29 | const char *fmt2 = "\e[34m" ; |
30 | static jmp_buf jmpbuf; |
31 | |
32 | #define handle_error(msg) \ |
33 | do { perror(msg); exit(EXIT_FAILURE); } while (0) |
34 | |
35 | __attribute__((noinline, noclone)) |
36 | static void |
37 | func4(ucontext_t *uocp, ucontext_t *ucp, const char *str, const char *fmt) |
38 | { |
39 | printf(format: " %sfunc4: %s\e[0m\n" , fmt, str); |
40 | if (swapcontext(oucp: uocp, ucp: ucp) == -1) |
41 | handle_error("swapcontext" ); |
42 | printf(format: " %sfunc4: returning\e[0m\n" , fmt); |
43 | } |
44 | |
45 | __attribute__((noinline, noclone)) |
46 | static void |
47 | func3(ucontext_t *uocp, ucontext_t *ucp, const char *str, const char *fmt) |
48 | { |
49 | printf(format: " %sfunc3: func4(uocp, ucp, str)\e[0m\n" , fmt); |
50 | func4(uocp, ucp, str, fmt); |
51 | printf(format: " %sfunc3: returning\e[0m\n" , fmt); |
52 | } |
53 | |
54 | __attribute__((noinline, noclone)) |
55 | static void |
56 | func1(void) |
57 | { |
58 | while ( 1 ) |
59 | { |
60 | printf(format: " \e[31mfunc1: func3(&uctx_func1, &uctx_main, str1)\e[0m\n" ); |
61 | if (setjmp (jmpbuf) != 0) |
62 | { |
63 | printf(format: " %sfunc1: from longjmp\e[0m\n" , fmt1); |
64 | exit (EXIT_SUCCESS); |
65 | } |
66 | func3( uocp: &uctx_func1, ucp: &uctx_main, str: str1, fmt: fmt1); |
67 | } |
68 | } |
69 | |
70 | __attribute__((noinline, noclone)) |
71 | static void |
72 | func2(void) |
73 | { |
74 | while ( 1 ) |
75 | { |
76 | printf(format: " \e[34mfunc2: func3(&uctx_func2, &uctx_main, str2)\e[0m\n" ); |
77 | func3(uocp: &uctx_func2, ucp: &uctx_main, str: str2, fmt: fmt2); |
78 | printf(format: " %sfunc2: calling longjmp\e[0m\n" , fmt2); |
79 | longjmp (jmpbuf, 1); |
80 | } |
81 | } |
82 | |
83 | static int |
84 | do_test (void) |
85 | { |
86 | /* ____longjmp_chk has */ |
87 | #if 0 |
88 | #ifdef _STACK_GROWS_DOWN |
89 | #define called_from(this, saved) ((this) < (saved)) |
90 | #else |
91 | #define called_from(this, saved) ((this) > (saved)) |
92 | #endif |
93 | |
94 | /* If "env" is from a frame that called us, we're all set. */ |
95 | if (called_from(this_frame, saved_frame)) |
96 | __longjmp (env, val); |
97 | #endif |
98 | /* Arrange stacks for uctx_func1 and uctx_func2 so that called_from |
99 | is true when setjmp is called from uctx_func1 and longjmp is called |
100 | from uctx_func2. */ |
101 | #ifdef _STACK_GROWS_DOWN |
102 | # define UCTX_FUNC1_STACK 1 |
103 | # define UCTX_FUNC2_STACK 0 |
104 | #else |
105 | # define UCTX_FUNC1_STACK 0 |
106 | # define UCTX_FUNC2_STACK 1 |
107 | #endif |
108 | char func_stack[2][16384]; |
109 | int i; |
110 | |
111 | if (getcontext(ucp: &uctx_func1) == -1) |
112 | handle_error("getcontext" ); |
113 | uctx_func1.uc_stack.ss_sp = func_stack[UCTX_FUNC1_STACK]; |
114 | uctx_func1.uc_stack.ss_size = sizeof (func_stack[UCTX_FUNC1_STACK]); |
115 | uctx_func1.uc_link = &uctx_main; |
116 | makecontext(ucp: &uctx_func1, func: func1, argc: 0); |
117 | |
118 | if (getcontext(ucp: &uctx_func2) == -1) |
119 | handle_error("getcontext" ); |
120 | uctx_func2.uc_stack.ss_sp = func_stack[UCTX_FUNC2_STACK]; |
121 | uctx_func2.uc_stack.ss_size = sizeof (func_stack[UCTX_FUNC2_STACK]); |
122 | uctx_func2.uc_link = &uctx_func1; |
123 | makecontext(ucp: &uctx_func2, func: func2, argc: 0); |
124 | |
125 | for ( i = 0; i < 2; i++ ) |
126 | { |
127 | if (swapcontext(oucp: &uctx_main, ucp: &uctx_func1) == -1) |
128 | handle_error("swapcontext" ); |
129 | printf(format: " \e[35mmain: swapcontext(&uctx_main, &uctx_func2)\n\e[0m" ); |
130 | if (swapcontext(oucp: &uctx_main, ucp: &uctx_func2) == -1) |
131 | handle_error("swapcontext" ); |
132 | printf(format: " \e[35mmain: swapcontext(&uctx_main, &uctx_func1)\n\e[0m" ); |
133 | } |
134 | |
135 | exit(EXIT_FAILURE); |
136 | } |
137 | |
138 | #include <support/test-driver.c> |
139 | |