xref: /third_party/musl/src/conf/sysconf.c (revision 570af302)
1#include <unistd.h>
2#include <limits.h>
3#include <errno.h>
4#include <sys/resource.h>
5#include <signal.h>
6#include <sys/sysinfo.h>
7#include <sys/auxv.h>
8#include "syscall.h"
9#include "libc.h"
10
11#define JT(x) (-256|(x))
12#define VER JT(1)
13#define JT_ARG_MAX JT(2)
14#define JT_MQ_PRIO_MAX JT(3)
15#define JT_PAGE_SIZE JT(4)
16#define JT_SEM_VALUE_MAX JT(5)
17#define JT_NPROCESSORS_CONF JT(6)
18#define JT_NPROCESSORS_ONLN JT(7)
19#define JT_PHYS_PAGES JT(8)
20#define JT_AVPHYS_PAGES JT(9)
21#define JT_ZERO JT(10)
22#define JT_DELAYTIMER_MAX JT(11)
23#define JT_MINSIGSTKSZ JT(12)
24#define JT_SIGSTKSZ JT(13)
25
26#define RLIM(x) (-32768|(RLIMIT_ ## x))
27
28long sysconf(int name)
29{
30#ifdef __LITEOS_A__
31	return syscall(SYS_sysconf, name);
32#else
33	static const short values[] = {
34		[_SC_ARG_MAX] = JT_ARG_MAX,
35		[_SC_CHILD_MAX] = RLIM(NPROC),
36		[_SC_CLK_TCK] = 100,
37		[_SC_NGROUPS_MAX] = 32,
38		[_SC_OPEN_MAX] = RLIM(NOFILE),
39		[_SC_STREAM_MAX] = -1,
40		[_SC_TZNAME_MAX] = TZNAME_MAX,
41		[_SC_JOB_CONTROL] = 1,
42		[_SC_SAVED_IDS] = 1,
43		[_SC_REALTIME_SIGNALS] = VER,
44		[_SC_PRIORITY_SCHEDULING] = -1,
45		[_SC_TIMERS] = VER,
46		[_SC_ASYNCHRONOUS_IO] = VER,
47		[_SC_PRIORITIZED_IO] = -1,
48		[_SC_SYNCHRONIZED_IO] = -1,
49		[_SC_FSYNC] = VER,
50		[_SC_MAPPED_FILES] = VER,
51		[_SC_MEMLOCK] = VER,
52		[_SC_MEMLOCK_RANGE] = VER,
53		[_SC_MEMORY_PROTECTION] = VER,
54		[_SC_MESSAGE_PASSING] = VER,
55		[_SC_SEMAPHORES] = VER,
56		[_SC_SHARED_MEMORY_OBJECTS] = VER,
57		[_SC_AIO_LISTIO_MAX] = -1,
58		[_SC_AIO_MAX] = -1,
59		[_SC_AIO_PRIO_DELTA_MAX] = JT_ZERO, /* ?? */
60		[_SC_DELAYTIMER_MAX] = JT_DELAYTIMER_MAX,
61		[_SC_MQ_OPEN_MAX] = -1,
62		[_SC_MQ_PRIO_MAX] = JT_MQ_PRIO_MAX,
63		[_SC_VERSION] = VER,
64		[_SC_PAGE_SIZE] = JT_PAGE_SIZE,
65		[_SC_RTSIG_MAX] = _NSIG - 1 - 31 - 3,
66		[_SC_SEM_NSEMS_MAX] = SEM_NSEMS_MAX,
67		[_SC_SEM_VALUE_MAX] = JT_SEM_VALUE_MAX,
68		[_SC_SIGQUEUE_MAX] = -1,
69		[_SC_TIMER_MAX] = -1,
70		[_SC_BC_BASE_MAX] = _POSIX2_BC_BASE_MAX,
71		[_SC_BC_DIM_MAX] = _POSIX2_BC_DIM_MAX,
72		[_SC_BC_SCALE_MAX] = _POSIX2_BC_SCALE_MAX,
73		[_SC_BC_STRING_MAX] = _POSIX2_BC_STRING_MAX,
74		[_SC_COLL_WEIGHTS_MAX] = COLL_WEIGHTS_MAX,
75		[_SC_EXPR_NEST_MAX] = -1,
76		[_SC_LINE_MAX] = -1,
77		[_SC_RE_DUP_MAX] = RE_DUP_MAX,
78		[_SC_2_VERSION] = VER,
79		[_SC_2_C_BIND] = VER,
80		[_SC_2_C_DEV] = -1,
81		[_SC_2_FORT_DEV] = -1,
82		[_SC_2_FORT_RUN] = -1,
83		[_SC_2_SW_DEV] = -1,
84		[_SC_2_LOCALEDEF] = -1,
85		[_SC_IOV_MAX] = IOV_MAX,
86		[_SC_THREADS] = VER,
87		[_SC_THREAD_SAFE_FUNCTIONS] = VER,
88		[_SC_GETGR_R_SIZE_MAX] = -1,
89		[_SC_GETPW_R_SIZE_MAX] = -1,
90		[_SC_LOGIN_NAME_MAX] = 256,
91		[_SC_TTY_NAME_MAX] = TTY_NAME_MAX,
92		[_SC_THREAD_DESTRUCTOR_ITERATIONS] = PTHREAD_DESTRUCTOR_ITERATIONS,
93		[_SC_THREAD_KEYS_MAX] = PTHREAD_KEYS_MAX,
94		[_SC_THREAD_STACK_MIN] = PTHREAD_STACK_MIN,
95		[_SC_THREAD_THREADS_MAX] = -1,
96		[_SC_THREAD_ATTR_STACKADDR] = VER,
97		[_SC_THREAD_ATTR_STACKSIZE] = VER,
98		[_SC_THREAD_PRIORITY_SCHEDULING] = VER,
99		[_SC_THREAD_PRIO_INHERIT] = -1,
100		[_SC_THREAD_PRIO_PROTECT] = -1,
101		[_SC_THREAD_PROCESS_SHARED] = VER,
102		[_SC_NPROCESSORS_CONF] = JT_NPROCESSORS_CONF,
103		[_SC_NPROCESSORS_ONLN] = JT_NPROCESSORS_ONLN,
104		[_SC_PHYS_PAGES] = JT_PHYS_PAGES,
105		[_SC_AVPHYS_PAGES] = JT_AVPHYS_PAGES,
106		[_SC_ATEXIT_MAX] = -1,
107		[_SC_PASS_MAX] = -1,
108		[_SC_XOPEN_VERSION] = _XOPEN_VERSION,
109		[_SC_XOPEN_XCU_VERSION] = _XOPEN_VERSION,
110		[_SC_XOPEN_UNIX] = 1,
111		[_SC_XOPEN_CRYPT] = -1,
112		[_SC_XOPEN_ENH_I18N] = 1,
113		[_SC_XOPEN_SHM] = 1,
114		[_SC_2_CHAR_TERM] = -1,
115		[_SC_2_UPE] = -1,
116		[_SC_XOPEN_XPG2] = -1,
117		[_SC_XOPEN_XPG3] = -1,
118		[_SC_XOPEN_XPG4] = -1,
119		[_SC_NZERO] = NZERO,
120		[_SC_XBS5_ILP32_OFF32] = -1,
121		[_SC_XBS5_ILP32_OFFBIG] = sizeof(long)==4 ? 1 : -1,
122		[_SC_XBS5_LP64_OFF64] = sizeof(long)==8 ? 1 : -1,
123		[_SC_XBS5_LPBIG_OFFBIG] = -1,
124		[_SC_XOPEN_LEGACY] = -1,
125		[_SC_XOPEN_REALTIME] = -1,
126		[_SC_XOPEN_REALTIME_THREADS] = -1,
127		[_SC_ADVISORY_INFO] = VER,
128		[_SC_BARRIERS] = VER,
129		[_SC_CLOCK_SELECTION] = VER,
130		[_SC_CPUTIME] = VER,
131		[_SC_THREAD_CPUTIME] = VER,
132		[_SC_MONOTONIC_CLOCK] = VER,
133		[_SC_READER_WRITER_LOCKS] = VER,
134		[_SC_SPIN_LOCKS] = VER,
135		[_SC_REGEXP] = 1,
136		[_SC_SHELL] = 1,
137		[_SC_SPAWN] = VER,
138		[_SC_SPORADIC_SERVER] = -1,
139		[_SC_THREAD_SPORADIC_SERVER] = -1,
140		[_SC_TIMEOUTS] = VER,
141		[_SC_TYPED_MEMORY_OBJECTS] = -1,
142		[_SC_2_PBS] = -1,
143		[_SC_2_PBS_ACCOUNTING] = -1,
144		[_SC_2_PBS_LOCATE] = -1,
145		[_SC_2_PBS_MESSAGE] = -1,
146		[_SC_2_PBS_TRACK] = -1,
147		[_SC_SYMLOOP_MAX] = SYMLOOP_MAX,
148		[_SC_STREAMS] = JT_ZERO,
149		[_SC_2_PBS_CHECKPOINT] = -1,
150		[_SC_V6_ILP32_OFF32] = -1,
151		[_SC_V6_ILP32_OFFBIG] = sizeof(long)==4 ? 1 : -1,
152		[_SC_V6_LP64_OFF64] = sizeof(long)==8 ? 1 : -1,
153		[_SC_V6_LPBIG_OFFBIG] = -1,
154		[_SC_HOST_NAME_MAX] = HOST_NAME_MAX,
155		[_SC_TRACE] = -1,
156		[_SC_TRACE_EVENT_FILTER] = -1,
157		[_SC_TRACE_INHERIT] = -1,
158		[_SC_TRACE_LOG] = -1,
159
160		[_SC_IPV6] = VER,
161		[_SC_RAW_SOCKETS] = VER,
162		[_SC_V7_ILP32_OFF32] = -1,
163		[_SC_V7_ILP32_OFFBIG] = sizeof(long)==4 ? 1 : -1,
164		[_SC_V7_LP64_OFF64] = sizeof(long)==8 ? 1 : -1,
165		[_SC_V7_LPBIG_OFFBIG] = -1,
166		[_SC_SS_REPL_MAX] = -1,
167		[_SC_TRACE_EVENT_NAME_MAX] = -1,
168		[_SC_TRACE_NAME_MAX] = -1,
169		[_SC_TRACE_SYS_MAX] = -1,
170		[_SC_TRACE_USER_EVENT_MAX] = -1,
171		[_SC_XOPEN_STREAMS] = JT_ZERO,
172		[_SC_THREAD_ROBUST_PRIO_INHERIT] = -1,
173		[_SC_THREAD_ROBUST_PRIO_PROTECT] = -1,
174
175		[_SC_MINSIGSTKSZ] = JT_MINSIGSTKSZ,
176		[_SC_SIGSTKSZ] = JT_SIGSTKSZ,
177	};
178
179	if (name >= sizeof(values)/sizeof(values[0]) || !values[name]) {
180		errno = EINVAL;
181		return -1;
182	} else if (values[name] >= -1) {
183		return values[name];
184	} else if (values[name] < -256) {
185		struct rlimit lim;
186		getrlimit(values[name]&16383, &lim);
187		if (lim.rlim_cur == RLIM_INFINITY)
188			return -1;
189		return lim.rlim_cur > LONG_MAX ? LONG_MAX : lim.rlim_cur;
190	}
191
192	switch ((unsigned char)values[name]) {
193	case VER & 255:
194		return _POSIX_VERSION;
195	case JT_ARG_MAX & 255:
196		return ARG_MAX;
197	case JT_MQ_PRIO_MAX & 255:
198		return MQ_PRIO_MAX;
199	case JT_PAGE_SIZE & 255:
200		return PAGE_SIZE;
201	case JT_SEM_VALUE_MAX & 255:
202		return SEM_VALUE_MAX;
203	case JT_DELAYTIMER_MAX & 255:
204		return DELAYTIMER_MAX;
205	case JT_NPROCESSORS_CONF & 255:
206		return get_nprocs_conf();
207	case JT_NPROCESSORS_ONLN & 255:
208		return get_nprocs();
209	case JT_PHYS_PAGES & 255:
210	case JT_AVPHYS_PAGES & 255: ;
211		unsigned long long mem;
212		struct sysinfo si;
213		__lsysinfo(&si);
214		if (!si.mem_unit) si.mem_unit = 1;
215		if (name==_SC_PHYS_PAGES) mem = si.totalram;
216		else mem = si.freeram + si.bufferram;
217		mem *= si.mem_unit;
218		mem /= PAGE_SIZE;
219		return (mem > LONG_MAX) ? LONG_MAX : mem;
220	case JT_MINSIGSTKSZ & 255:
221	case JT_SIGSTKSZ & 255: ;
222		long val = __getauxval(AT_MINSIGSTKSZ);
223		if (val < MINSIGSTKSZ) val = MINSIGSTKSZ;
224		if (values[name] == JT_SIGSTKSZ)
225			val += SIGSTKSZ - MINSIGSTKSZ;
226		return val;
227	case JT_ZERO & 255:
228		return 0;
229	}
230	return values[name];
231#endif
232}
233