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958f238f UD |
1 | /* Set flags signalling availability of kernel features based on given |
2 | kernel version number. | |
581c785b | 3 | Copyright (C) 1999-2022 Free Software Foundation, Inc. |
958f238f UD |
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 | |
41bdb6e2 AJ |
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. | |
958f238f UD |
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 | |
41bdb6e2 | 14 | Lesser General Public License for more details. |
958f238f | 15 | |
41bdb6e2 | 16 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 | 17 | License along with the GNU C Library; if not, see |
5a82c748 | 18 | <https://www.gnu.org/licenses/>. */ |
958f238f UD |
19 | |
20 | /* This file must not contain any C code. At least it must be protected | |
21 | to allow using the file also in assembler files. */ | |
22 | ||
a26918cf LM |
23 | #ifndef _LINUX_KERNEL_FEATURES_H |
24 | #define _LINUX_KERNEL_FEATURES_H 1 | |
25 | ||
26 | #include <bits/wordsize.h> | |
27 | ||
958f238f UD |
28 | #ifndef __LINUX_KERNEL_VERSION |
29 | /* We assume the worst; all kernels should be supported. */ | |
30 | # define __LINUX_KERNEL_VERSION 0 | |
31 | #endif | |
32 | ||
33 | /* We assume for __LINUX_KERNEL_VERSION the same encoding used in | |
34 | linux/version.h. I.e., the major, minor, and subminor all get a | |
35 | byte with the major number being in the highest byte. This means | |
36 | we can do numeric comparisons. | |
37 | ||
38 | In the following we will define certain symbols depending on | |
39 | whether the describes kernel feature is available in the kernel | |
40 | version given by __LINUX_KERNEL_VERSION. We are not always exactly | |
41 | recording the correct versions in which the features were | |
42 | introduced. If somebody cares these values can afterwards be | |
ffb7875d | 43 | corrected. */ |
958f238f | 44 | |
7aab07e4 JM |
45 | /* The statfs64 syscalls are available in 2.5.74 (but not for alpha). */ |
46 | #define __ASSUME_STATFS64 1 | |
c801e765 | 47 | |
637461d9 JM |
48 | /* pselect/ppoll were introduced just after 2.6.16-rc1. On x86_64 and |
49 | SH this appeared first in 2.6.19-rc1, on ia64 in 2.6.22-rc1. */ | |
50 | #define __ASSUME_PSELECT 1 | |
7c65e900 | 51 | |
47c5adeb JM |
52 | /* Support for inter-process robust mutexes was added in 2.6.17 (but |
53 | some architectures lack futex_atomic_cmpxchg_inatomic in some | |
54 | configurations). */ | |
03f77315 | 55 | #define __ASSUME_SET_ROBUST_LIST 1 |
d5ba53f9 | 56 | |
5e7698c6 JM |
57 | /* Support for various CLOEXEC and NONBLOCK flags was added in |
58 | 2.6.27. */ | |
5e7698c6 | 59 | #define __ASSUME_IN_NONBLOCK 1 |
f93fc0b7 | 60 | |
e109c612 | 61 | /* Support for preadv and pwritev was added in 2.6.30. */ |
637461d9 JM |
62 | #define __ASSUME_PREADV 1 |
63 | #define __ASSUME_PWRITEV 1 | |
81c84bd9 | 64 | |
e3b0580d | 65 | /* Support for sendmmsg functionality was added in 3.0. */ |
0cb5da5c | 66 | #define __ASSUME_SENDMMSG 1 |
abf29edd AZ |
67 | |
68 | /* On most architectures, most socket syscalls are supported for all | |
69 | supported kernel versions, but on some socketcall architectures | |
70 | separate syscalls were only added later. */ | |
71 | #define __ASSUME_SENDMSG_SYSCALL 1 | |
72 | #define __ASSUME_RECVMSG_SYSCALL 1 | |
01061a7c | 73 | #define __ASSUME_ACCEPT_SYSCALL 1 |
3e9ff426 | 74 | #define __ASSUME_CONNECT_SYSCALL 1 |
1f8161a8 | 75 | #define __ASSUME_RECVFROM_SYSCALL 1 |
06cf371e | 76 | #define __ASSUME_SENDTO_SYSCALL 1 |
e3b0580d JM |
77 | #define __ASSUME_ACCEPT4_SYSCALL 1 |
78 | #define __ASSUME_RECVMMSG_SYSCALL 1 | |
79 | #define __ASSUME_SENDMMSG_SYSCALL 1 | |
1c46663a | 80 | #define __ASSUME_GETSOCKOPT_SYSCALL 1 |
4b93a93e | 81 | #define __ASSUME_SETSOCKOPT_SYSCALL 1 |
63719cf1 AZ |
82 | |
83 | /* Support for SysV IPC through wired syscalls. All supported architectures | |
84 | either support ipc syscall and/or all the ipc correspondent syscalls. */ | |
85 | #define __ASSUME_DIRECT_SYSVIPC_SYSCALLS 1 | |
06436acf AZ |
86 | /* The generic default __IPC_64 value is 0x0, however some architectures |
87 | require a different value of 0x100. */ | |
88 | #define __ASSUME_SYSVIPC_DEFAULT_IPC_64 1 | |
52bd9381 | 89 | |
2f959dfe AZ |
90 | /* All supported architectures reserve a 32-bit for MODE field in sysvipc |
91 | ipc_perm. However, some kernel ABI interfaces still expect a 16-bit | |
92 | field. This is only an issue if arch-defined IPC_PERM padding is on a | |
93 | wrong position regarding endianness. In this case, the IPC control | |
94 | routines (msgctl, semctl, and semtctl) requires to shift the value to | |
95 | correct place. | |
96 | The ABIs that requires it define __ASSUME_SYSVIPC_BROKEN_MODE_T. */ | |
97 | ||
52bd9381 AZ |
98 | /* Support for p{read,write}v2 was added in 4.6. However Linux default |
99 | implementation does not assume the __ASSUME_* and instead use a fallback | |
100 | implementation based on p{read,write}v and returning an error for | |
101 | non supported flags. */ | |
43ffc53a | 102 | |
d6da5cb6 FW |
103 | /* Support for the renameat2 system call was added in kernel 3.15. */ |
104 | #if __LINUX_KERNEL_VERSION >= 0x030F00 | |
105 | # define __ASSUME_RENAMEAT2 | |
106 | #endif | |
107 | ||
43ffc53a AS |
108 | /* Support for the execveat syscall was added in 3.19. */ |
109 | #if __LINUX_KERNEL_VERSION >= 0x031300 | |
110 | # define __ASSUME_EXECVEAT 1 | |
111 | #endif | |
4bab0224 FW |
112 | |
113 | #if __LINUX_KERNEL_VERSION >= 0x040400 | |
114 | # define __ASSUME_MLOCK2 1 | |
115 | #endif | |
bad7a0c8 | 116 | |
fd70af45 FW |
117 | /* Support for statx was added in kernel 4.11. */ |
118 | #if __LINUX_KERNEL_VERSION >= 0x040B00 | |
119 | # define __ASSUME_STATX 1 | |
120 | #endif | |
121 | ||
3dc21497 AZ |
122 | /* Support for clone call used on fork. The signature varies across the |
123 | architectures with current 4 different variants: | |
124 | ||
125 | 1. long int clone (unsigned long flags, unsigned long newsp, | |
126 | int *parent_tidptr, unsigned long tls, | |
127 | int *child_tidptr) | |
128 | ||
129 | 2. long int clone (unsigned long newsp, unsigned long clone_flags, | |
130 | int *parent_tidptr, int * child_tidptr, | |
131 | unsigned long tls) | |
132 | ||
133 | 3. long int clone (unsigned long flags, unsigned long newsp, | |
134 | int stack_size, int *parent_tidptr, | |
135 | int *child_tidptr, unsigned long tls) | |
136 | ||
137 | 4. long int clone (unsigned long flags, unsigned long newsp, | |
138 | int *parent_tidptr, int *child_tidptr, | |
139 | unsigned long tls) | |
140 | ||
141 | The fourth variant is intended to be used as the default for newer ports, | |
142 | Also IA64 uses the third variant but with __NR_clone2 instead of | |
143 | __NR_clone. | |
144 | ||
145 | The macros names to define the variant used for the architecture is | |
146 | similar to kernel: | |
147 | ||
148 | - __ASSUME_CLONE_BACKWARDS: for variant 1. | |
149 | - __ASSUME_CLONE_BACKWARDS2: for variant 2 (s390). | |
150 | - __ASSUME_CLONE_BACKWARDS3: for variant 3 (microblaze). | |
151 | - __ASSUME_CLONE_DEFAULT: for variant 4. | |
152 | - __ASSUME_CLONE2: for clone2 with variant 3 (ia64). | |
153 | */ | |
154 | ||
155 | #define __ASSUME_CLONE_DEFAULT 1 | |
a26918cf LM |
156 | |
157 | /* Support for 64-bit time_t in the system call interface. When this | |
158 | flag is set, the kernel provides a version of each of these system | |
159 | calls that accepts 64-bit time_t: | |
160 | ||
161 | clock_adjtime(64) | |
162 | clock_gettime(64) | |
163 | clock_settime(64) | |
164 | clock_getres(_time64) | |
165 | clock_nanosleep(_time64) | |
166 | futex(_time64) | |
167 | mq_timedreceive(_time64) | |
168 | mq_timedsend(_time64) | |
169 | ppoll(_time64) | |
170 | pselect6(_time64) | |
171 | rt_sigtimedwait(_time64) | |
172 | sched_rr_get_interval(_time64) | |
173 | timer_gettime(64) | |
174 | timer_settime(64) | |
175 | timerfd_gettime(64) | |
176 | timerfd_settime(64) | |
177 | utimensat(_time64) | |
178 | ||
179 | On architectures where time_t has historically been 64 bits, | |
180 | only the 64-bit version of each system call exists, and there | |
181 | are no suffixes on the __NR_ constants. | |
182 | ||
183 | On architectures where time_t has historically been 32 bits, | |
184 | both 32-bit and 64-bit versions of each system call may exist, | |
185 | depending on the kernel version. When the 64-bit version exists, | |
186 | there is a '64' or '_time64' suffix on the name of its __NR_ | |
187 | constant, as shown above. | |
188 | ||
189 | This flag is always set for Linux 5.1 and later. Prior to that | |
190 | version, it is set only for some CPU architectures and ABIs: | |
191 | ||
192 | - __WORDSIZE == 64 - all supported architectures where pointers | |
193 | are 64 bits also have always had 64-bit time_t. | |
194 | ||
195 | - __WORDSIZE == 32 && __SYSCALL_WORDSIZE == 64 - this describes | |
196 | only one supported configuration, x86's 'x32' subarchitecture, | |
197 | where pointers are 32 bits but time_t has always been 64 bits. | |
198 | ||
199 | __ASSUME_TIME64_SYSCALLS being set does not mean __TIMESIZE is 64, | |
200 | and __TIMESIZE equal to 64 does not mean __ASSUME_TIME64_SYSCALLS | |
201 | is set. All four cases are possible. */ | |
202 | ||
203 | #if __LINUX_KERNEL_VERSION >= 0x050100 \ | |
204 | || __WORDSIZE == 64 \ | |
205 | || (defined __SYSCALL_WORDSIZE && __SYSCALL_WORDSIZE == 64) | |
206 | # define __ASSUME_TIME64_SYSCALLS 1 | |
207 | #endif | |
208 | ||
9b2cf948 AZ |
209 | /* Linux waitid prior kernel 5.4 does not support waiting for the current |
210 | process group. */ | |
211 | #if __LINUX_KERNEL_VERSION >= 0x050400 | |
212 | # define __ASSUME_WAITID_PID0_P_PGID | |
213 | #endif | |
214 | ||
3d3ab573 FW |
215 | /* The faccessat2 system call was introduced across all architectures |
216 | in Linux 5.8. */ | |
217 | #if __LINUX_KERNEL_VERSION >= 0x050800 | |
218 | # define __ASSUME_FACCESSAT2 1 | |
219 | #else | |
220 | # define __ASSUME_FACCESSAT2 0 | |
221 | #endif | |
222 | ||
456b3c08 AZ |
223 | /* The close_range system call was introduced across all architectures |
224 | in Linux 5.9. */ | |
225 | #if __LINUX_KERNEL_VERSION >= 0x050900 | |
226 | # define __ASSUME_CLOSE_RANGE 1 | |
227 | #else | |
228 | # define __ASSUME_CLOSE_RANGE 0 | |
229 | #endif | |
230 | ||
dd5adb51 KK |
231 | /* The FUTEX_LOCK_PI2 operation was introduced across all architectures in Linux |
232 | 5.14. */ | |
233 | #if __LINUX_KERNEL_VERSION >= 0x050e00 | |
234 | # define __ASSUME_FUTEX_LOCK_PI2 1 | |
235 | #else | |
236 | # define __ASSUME_FUTEX_LOCK_PI2 0 | |
237 | #endif | |
238 | ||
a26918cf | 239 | #endif /* kernel-features.h */ |