1 /* Common extra functions.
2 Copyright (C) 2016-2021 Free Software Foundation, Inc.
3 Copyright The GNU Toolchain Authors.
4 This file is part of the GNU C Library.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20 /* This header file should only contain definitions compatible with
21 C90. (Using __attribute__ is fine because <features.h> provides a
22 fallback.) */
23
24 #ifndef SUPPORT_H
25 #define SUPPORT_H
26
27 #include <stdbool.h>
28 #include <stdint.h>
29 #include <stddef.h>
30 #include <sys/cdefs.h>
31 /* For mode_t. */
32 #include <sys/stat.h>
33 /* For ssize_t and off64_t. */
34 #include <sys/types.h>
35 /* For locale_t. */
36 #include <locale.h>
37
38 __BEGIN_DECLS
39
40 /* Write a message to standard output. Can be used in signal
41 handlers. */
42 void write_message (const char *message) __attribute__ ((nonnull (1)));
43
44 /* Avoid all the buffer overflow messages on stderr. */
45 void ignore_stderr (void);
46
47 /* Set fortification error handler. Used when tests want to verify that bad
48 code is caught by the library. */
49 void set_fortify_handler (void (*handler) (int sig));
50
51 /* Report an out-of-memory error for the allocation of SIZE bytes in
52 FUNCTION, terminating the process. */
53 void oom_error (const char *function, size_t size)
54 __attribute__ ((nonnull (1)));
55
56 /* Return a pointer to a memory region of SIZE bytes. The memory is
57 initialized to zero and will be shared with subprocesses (across
58 fork). The returned pointer must be freed using
59 support_shared_free; it is not compatible with the malloc
60 functions. */
61 void *support_shared_allocate (size_t size);
62
63 /* Deallocate a pointer returned by support_shared_allocate. */
64 void support_shared_free (void *);
65
66 /* Write CONTENTS to the file PATH. Create or truncate the file as
67 needed. The file mode is 0666 masked by the umask. Terminate the
68 process on error. */
69 void support_write_file_string (const char *path, const char *contents);
70
71 /* Quote the contents of the byte array starting at BLOB, of LENGTH
72 bytes, in such a way that the result string can be included in a C
73 literal (in single/double quotes, without putting the quotes into
74 the result). */
75 char *support_quote_blob (const void *blob, size_t length);
76
77 /* Quote the contents of the wide character array starting at BLOB, of
78 LENGTH wide characters, in such a way that the result string can be
79 included in a C wide string literal (in single/double quotes,
80 without putting the quotes into the result). */
81 char *support_quote_blob_wide (const void *blob, size_t length);
82
83 /* Quote the contents of the string, in such a way that the result
84 string can be included in a C literal (in single/double quotes,
85 without putting the quotes into the result). */
86 char *support_quote_string (const char *);
87
88 /* Returns non-zero if the file descriptor is a regular file on a file
89 system which supports holes (that is, seeking and writing does not
90 allocate storage for the range of zeros). FD must refer to a
91 regular file open for writing, and initially empty. */
92 int support_descriptor_supports_holes (int fd);
93
94 /* Error-checking wrapper functions which terminate the process on
95 error. */
96
97 extern void *xmalloc (size_t n)
98 __attribute_malloc__ __attribute_alloc_size__ ((1)) __attr_dealloc_free
99 __returns_nonnull;
100 extern void *xcalloc (size_t n, size_t s)
101 __attribute_malloc__ __attribute_alloc_size__ ((1, 2)) __attr_dealloc_free
102 __returns_nonnull;
103 extern void *xrealloc (void *o, size_t n)
104 __attribute_malloc__ __attribute_alloc_size__ ((2)) __attr_dealloc_free;
105 extern char *xstrdup (const char *) __attribute_malloc__ __attr_dealloc_free
106 __returns_nonnull;
107 void *xposix_memalign (size_t alignment, size_t n)
108 __attribute_malloc__ __attribute_alloc_align__ ((1))
109 __attribute_alloc_size__ ((2)) __attr_dealloc_free __returns_nonnull;
110 char *xasprintf (const char *format, ...)
111 __attribute__ ((format (printf, 1, 2), malloc)) __attr_dealloc_free
112 __returns_nonnull;
113 char *xstrdup (const char *) __attr_dealloc_free __returns_nonnull;
114 char *xstrndup (const char *, size_t) __attr_dealloc_free __returns_nonnull;
115 char *xsetlocale (int category, const char *locale);
116 locale_t xnewlocale (int category_mask, const char *locale, locale_t base);
117 char *xuselocale (locale_t newloc);
118
119 /* These point to the TOP of the source/build tree, not your (or
120 support's) subdirectory. */
121 extern const char support_srcdir_root[];
122 extern const char support_objdir_root[];
123
124 /* Corresponds to the path to the runtime linker used by the testsuite,
125 e.g. OBJDIR_PATH/elf/ld-linux-x86-64.so.2 */
126 extern const char support_objdir_elf_ldso[];
127
128 /* Corresponds to the --prefix= passed to configure. */
129 extern const char support_install_prefix[];
130 /* Corresponds to the install's lib/ or lib64/ directory. */
131 extern const char support_libdir_prefix[];
132 /* Corresponds to the install's bin/ directory. */
133 extern const char support_bindir_prefix[];
134 /* Corresponds to the install's sbin/ directory. */
135 extern const char support_sbindir_prefix[];
136 /* Corresponds to the install's system /lib or /lib64 directory. */
137 extern const char support_slibdir_prefix[];
138 /* Corresponds to the install's sbin/ directory (without prefix). */
139 extern const char support_install_rootsbindir[];
140 /* Corresponds to the install's compiled locale directory. */
141 extern const char support_complocaledir_prefix[];
142
143 /* Copies the file at the path FROM to TO. If TO does not exist, it
144 is created. If TO is a regular file, it is truncated before
145 copying. The file mode is copied, but the permissions are not. */
146 extern void support_copy_file (const char *from, const char *to);
147
148 extern ssize_t support_copy_file_range (int, off64_t *, int, off64_t *,
149 size_t, unsigned int);
150
151 /* Return true if PATH supports 64-bit time_t interfaces for file
152 operations (such as fstatat or utimensat). */
153 extern bool support_path_support_time64_value (const char *path, int64_t at,
154 int64_t mt);
support_path_support_time64(const char * path)155 static __inline bool support_path_support_time64 (const char *path)
156 {
157 /* 1s and 2s after y2038 limit. */
158 return support_path_support_time64_value (path, 0x80000001ULL,
159 0x80000002ULL);
160 }
161
162 /* Return true if the setitimer and getitimer syscalls support 64-bit time_t
163 values without resulting in overflow. This is not true on some linux systems
164 which have 64-bit time_t due to legacy kernel API's. */
support_itimer_support_time64(void)165 static __inline bool support_itimer_support_time64 (void)
166 {
167 #ifdef __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
168 return __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64;
169 #else
170 return sizeof (__time_t) == 8;
171 #endif
172 }
173
174 /* Return true if stat supports nanoseconds resolution. PATH is used
175 for tests and its ctime may change. */
176 extern bool support_stat_nanoseconds (const char *path);
177
178 /* Return true if select modify the timeout to reflect the amount of time
179 no slept. */
180 extern bool support_select_modifies_timeout (void);
181
182 /* Return true if select normalize the timeout input by taking in account
183 tv_usec larger than 1000000. */
184 extern bool support_select_normalizes_timeout (void);
185
186 /* Create a timer that trigger after SEC seconds and NSEC nanoseconds. If
187 REPEAT is true the timer will repeat indefinitely. If CALLBACK is not
188 NULL, the function will be called when the timer expires; otherwise a
189 dummy empty function is used instead.
190 This is implemented with POSIX per-process timer with SIGEV_SIGNAL. */
191 timer_t support_create_timer (uint64_t sec, long int nsec, bool repeat,
192 void (*callback)(int));
193 /* Disable the timer TIMER. */
194 void support_delete_timer (timer_t timer);
195
196 /* Wait until all threads except the current thread have exited (as
197 far as the kernel is concerned). */
198 void support_wait_for_thread_exit (void);
199
200 struct support_stack
201 {
202 void *stack;
203 size_t size;
204 size_t guardsize;
205 };
206
207 /* Allocate stack suitable to used with xclone or sigaltstack call. The stack
208 will have a minimum size of SIZE + MINSIGSTKSZ bytes, rounded up to a whole
209 number of pages. There will be a large (at least 1 MiB) inaccessible guard
210 bands on either side of it.
211 The returned value on ALLOC_BASE and ALLOC_SIZE will be the usable stack
212 region, excluding the GUARD_SIZE allocated area.
213 It also terminates the process on error. */
214 struct support_stack support_stack_alloc (size_t size);
215
216 /* Deallocate the STACK. */
217 void support_stack_free (struct support_stack *stack);
218
219
220 /* Create a range of NUM opened '/dev/null' file descriptors using FLAGS and
221 MODE. The function takes care of restarting the open range if a file
222 descriptor is found within the specified range and also increases
223 RLIMIT_NOFILE if required.
224 The returned value is the lowest file descriptor number. */
225 int support_open_dev_null_range (int num, int flags, mode_t mode);
226
227 __END_DECLS
228
229 #endif /* SUPPORT_H */
230