| /* |
| * Copyright (C) 2008 The Android Open Source Project |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <limits.h> |
| #include <pthread.h> |
| #include <stdio.h> // For FOPEN_MAX. |
| #include <sys/auxv.h> |
| #include <sys/param.h> |
| #include <sys/resource.h> |
| #include <sys/sysinfo.h> |
| #include <time.h> |
| #include <unistd.h> |
| |
| #include "platform/bionic/page.h" |
| #include "private/bionic_tls.h" |
| |
| struct sysconf_cache { |
| long size, assoc, linesize; |
| |
| static sysconf_cache from_size_and_geometry(int size_id, int geometry_id) { |
| sysconf_cache result; |
| result.size = getauxval(size_id); |
| unsigned long geometry = getauxval(geometry_id); |
| result.assoc = geometry >> 16; |
| result.linesize = geometry & 0xffff; |
| return result; |
| } |
| }; |
| |
| struct sysconf_caches { |
| sysconf_cache l1_i, l1_d, l2, l3, l4; |
| }; |
| |
| #if defined(__riscv) |
| |
| static sysconf_caches* __sysconf_caches() { |
| static sysconf_caches cached = []{ |
| sysconf_caches info = {}; |
| // riscv64 kernels conveniently hand us all this information. |
| info.l1_i = sysconf_cache::from_size_and_geometry(AT_L1I_CACHESIZE, AT_L1I_CACHEGEOMETRY); |
| info.l1_d = sysconf_cache::from_size_and_geometry(AT_L1D_CACHESIZE, AT_L1D_CACHEGEOMETRY); |
| info.l2 = sysconf_cache::from_size_and_geometry(AT_L2_CACHESIZE, AT_L2_CACHEGEOMETRY); |
| info.l3 = sysconf_cache::from_size_and_geometry(AT_L3_CACHESIZE, AT_L3_CACHEGEOMETRY); |
| return info; |
| }(); |
| return &cached; |
| } |
| |
| #elif defined(__aarch64__) |
| |
| static sysconf_caches* __sysconf_caches() { |
| static sysconf_caches cached = []{ |
| sysconf_caches info = {}; |
| // arm64 is especially limited. We can infer the L1 line sizes, but that's it. |
| uint64_t ctr_el0; |
| __asm__ __volatile__("mrs %0, ctr_el0" : "=r"(ctr_el0)); |
| info.l1_i.linesize = 4 << (ctr_el0 & 0xf); |
| info.l1_d.linesize = 4 << ((ctr_el0 >> 16) & 0xf); |
| return info; |
| }(); |
| return &cached; |
| } |
| |
| #else |
| |
| static long __sysconf_fread_long(const char* path) { |
| long result = 0; |
| FILE* fp = fopen(path, "re"); |
| if (fp != nullptr) { |
| fscanf(fp, "%ld", &result); |
| fclose(fp); |
| } |
| return result; |
| } |
| |
| static sysconf_caches* __sysconf_caches() { |
| static sysconf_caches cached = []{ |
| sysconf_caches info = {}; |
| char path[64]; |
| for (int i = 0; i < 4; i++) { |
| sysconf_cache c; |
| |
| snprintf(path, sizeof(path), "/sys/devices/system/cpu/cpu0/cache/index%d/size", i); |
| c.size = __sysconf_fread_long(path) * 1024; |
| if (c.size == 0) break; |
| |
| snprintf(path, sizeof(path), "/sys/devices/system/cpu/cpu0/cache/index%d/ways_of_associativity", i); |
| c.assoc = __sysconf_fread_long(path); |
| |
| snprintf(path, sizeof(path), "/sys/devices/system/cpu/cpu0/cache/index%d/coherency_line_size", i); |
| c.linesize = __sysconf_fread_long(path); |
| |
| snprintf(path, sizeof(path), "/sys/devices/system/cpu/cpu0/cache/index%d/level", i); |
| int level = __sysconf_fread_long(path); |
| if (level == 1) { |
| snprintf(path, sizeof(path), "/sys/devices/system/cpu/cpu0/cache/index%d/type", i); |
| FILE* fp = fopen(path, "re"); |
| char type = fgetc(fp); |
| fclose(fp); |
| if (type == 'D') { |
| info.l1_d = c; |
| } else if (type == 'I') { |
| info.l1_i = c; |
| } |
| } else if (level == 2) { |
| info.l2 = c; |
| } else if (level == 3) { |
| info.l3 = c; |
| } |
| } |
| return info; |
| }(); |
| return &cached; |
| } |
| |
| #endif |
| |
| static long __sysconf_rlimit(int resource) { |
| rlimit rl; |
| getrlimit(resource, &rl); |
| return rl.rlim_cur; |
| } |
| |
| long sysconf(int name) { |
| switch (name) { |
| // |
| // Things we actually have to calculate... |
| // |
| case _SC_ARG_MAX: |
| // You might think that just returning a constant 128KiB (ARG_MAX) would |
| // make sense, as this guy did: |
| // |
| // https://lkml.org/lkml/2017/11/15/813... |
| // |
| // I suspect a 128kB sysconf(_SC_ARG_MAX) is the sanest bet, simply |
| // because of that "conservative is better than aggressive". |
| // |
| // Especially since _technically_ we're still limiting things to that |
| // 128kB due to the single-string limit. |
| // |
| // Linus |
| // |
| // In practice that caused us trouble with toybox tests for xargs edge |
| // cases. The tests assume that they can at least reach the kernel's |
| // "minimum maximum" of 128KiB, but if we report 128KiB for _SC_ARG_MAX |
| // and xargs starts subtracting the environment space and so on from that, |
| // then xargs will think it's run out of space when given 128KiB of data, |
| // which should always work. See this thread for more: |
| // |
| // http://lists.landley.net/pipermail/toybox-landley.net/2019-November/011229.html |
| // |
| // So let's resign ourselves to tracking what the kernel actually does. |
| // Right now (2019, Linux 5.3) that amounts to: |
| return MAX(MIN(__sysconf_rlimit(RLIMIT_STACK) / 4, 3 * _STK_LIM / 4), ARG_MAX); |
| |
| case _SC_AVPHYS_PAGES: return get_avphys_pages(); |
| case _SC_CHILD_MAX: return __sysconf_rlimit(RLIMIT_NPROC); |
| case _SC_CLK_TCK: |
| return static_cast<long>(getauxval(AT_CLKTCK)); |
| case _SC_NPROCESSORS_CONF: return get_nprocs_conf(); |
| case _SC_NPROCESSORS_ONLN: return get_nprocs(); |
| case _SC_OPEN_MAX: return __sysconf_rlimit(RLIMIT_NOFILE); |
| |
| case _SC_PAGESIZE: |
| case _SC_PAGE_SIZE: |
| // _SC_PAGESIZE and _SC_PAGE_SIZE are distinct, but return the same value. |
| return getpagesize(); |
| |
| case _SC_PHYS_PAGES: return get_phys_pages(); |
| |
| // |
| // Constants... |
| // |
| case _SC_BC_BASE_MAX: return _POSIX2_BC_BASE_MAX; // Minimum requirement. |
| case _SC_BC_DIM_MAX: return _POSIX2_BC_DIM_MAX; // Minimum requirement. |
| case _SC_BC_SCALE_MAX: return _POSIX2_BC_SCALE_MAX; // Minimum requirement. |
| case _SC_BC_STRING_MAX: return _POSIX2_BC_STRING_MAX; // Minimum requirement. |
| case _SC_COLL_WEIGHTS_MAX: return _POSIX2_COLL_WEIGHTS_MAX; // Minimum requirement. |
| case _SC_EXPR_NEST_MAX: return _POSIX2_EXPR_NEST_MAX; // Minimum requirement. |
| case _SC_LINE_MAX: return _POSIX2_LINE_MAX; // Minimum requirement. |
| case _SC_NGROUPS_MAX: |
| // Only root can read /proc/sys/kernel/ngroups_max on Android, and groups |
| // are vestigial anyway, so the "maximum maximum" of NGROUPS_MAX is a good |
| // enough answer for _SC_NGROUPS_MAX... |
| return NGROUPS_MAX; |
| case _SC_PASS_MAX: return PASS_MAX; |
| case _SC_2_C_BIND: return _POSIX2_C_BIND; |
| case _SC_2_C_DEV: return _POSIX2_C_DEV; |
| case _SC_2_CHAR_TERM: return _POSIX2_CHAR_TERM; |
| case _SC_2_FORT_DEV: return -1; |
| case _SC_2_FORT_RUN: return -1; |
| case _SC_2_LOCALEDEF: return _POSIX2_LOCALEDEF; |
| case _SC_2_SW_DEV: return _POSIX2_SW_DEV; |
| case _SC_2_UPE: return _POSIX2_UPE; |
| case _SC_2_VERSION: return _POSIX2_VERSION; |
| case _SC_JOB_CONTROL: return _POSIX_JOB_CONTROL; |
| case _SC_SAVED_IDS: return _POSIX_SAVED_IDS; |
| case _SC_VERSION: return _POSIX_VERSION; |
| case _SC_RE_DUP_MAX: return _POSIX_RE_DUP_MAX; // Minimum requirement. |
| case _SC_STREAM_MAX: return FOPEN_MAX; |
| case _SC_TZNAME_MAX: return _POSIX_TZNAME_MAX; // Minimum requirement. |
| case _SC_XOPEN_CRYPT: return _XOPEN_CRYPT; |
| case _SC_XOPEN_ENH_I18N: return _XOPEN_ENH_I18N; |
| case _SC_XOPEN_SHM: return _XOPEN_SHM; |
| case _SC_XOPEN_VERSION: return _XOPEN_VERSION; |
| case _SC_XOPEN_REALTIME: return _XOPEN_REALTIME; |
| case _SC_XOPEN_REALTIME_THREADS: return _XOPEN_REALTIME_THREADS; |
| case _SC_XOPEN_LEGACY: return _XOPEN_LEGACY; |
| case _SC_ATEXIT_MAX: return LONG_MAX; // Unlimited. |
| case _SC_IOV_MAX: return IOV_MAX; |
| |
| case _SC_XOPEN_UNIX: return _XOPEN_UNIX; |
| case _SC_AIO_LISTIO_MAX: return _POSIX_AIO_LISTIO_MAX; // Minimum requirement. |
| case _SC_AIO_MAX: return _POSIX_AIO_MAX; // Minimum requirement. |
| case _SC_AIO_PRIO_DELTA_MAX:return 0; // Minimum requirement. |
| case _SC_DELAYTIMER_MAX: return _POSIX_DELAYTIMER_MAX; |
| case _SC_MQ_OPEN_MAX: return _POSIX_MQ_OPEN_MAX; // Minimum requirement. |
| case _SC_MQ_PRIO_MAX: return _POSIX_MQ_PRIO_MAX; // Minimum requirement. |
| case _SC_RTSIG_MAX: return RTSIG_MAX; |
| case _SC_SEM_NSEMS_MAX: return _POSIX_SEM_NSEMS_MAX; // Minimum requirement. |
| case _SC_SEM_VALUE_MAX: return SEM_VALUE_MAX; |
| case _SC_SIGQUEUE_MAX: return _POSIX_SIGQUEUE_MAX; // Minimum requirement. |
| case _SC_TIMER_MAX: return _POSIX_TIMER_MAX; // Minimum requirement. |
| case _SC_ASYNCHRONOUS_IO: return _POSIX_ASYNCHRONOUS_IO; |
| case _SC_FSYNC: return _POSIX_FSYNC; |
| case _SC_MAPPED_FILES: return _POSIX_MAPPED_FILES; |
| case _SC_MEMLOCK: return _POSIX_MEMLOCK; |
| case _SC_MEMLOCK_RANGE: return _POSIX_MEMLOCK_RANGE; |
| case _SC_MEMORY_PROTECTION: return _POSIX_MEMORY_PROTECTION; |
| case _SC_MESSAGE_PASSING: return _POSIX_MESSAGE_PASSING; |
| case _SC_PRIORITIZED_IO: return _POSIX_PRIORITIZED_IO; |
| case _SC_PRIORITY_SCHEDULING: return _POSIX_PRIORITY_SCHEDULING; |
| case _SC_REALTIME_SIGNALS: return _POSIX_REALTIME_SIGNALS; |
| case _SC_SEMAPHORES: return _POSIX_SEMAPHORES; |
| case _SC_SHARED_MEMORY_OBJECTS: return _POSIX_SHARED_MEMORY_OBJECTS; |
| case _SC_SYNCHRONIZED_IO: return _POSIX_SYNCHRONIZED_IO; |
| case _SC_TIMERS: return _POSIX_TIMERS; |
| case _SC_GETGR_R_SIZE_MAX: return 1024; |
| case _SC_GETPW_R_SIZE_MAX: return 1024; |
| case _SC_LOGIN_NAME_MAX: return LOGIN_NAME_MAX; |
| case _SC_THREAD_DESTRUCTOR_ITERATIONS: return PTHREAD_DESTRUCTOR_ITERATIONS; |
| case _SC_THREAD_KEYS_MAX: return PTHREAD_KEYS_MAX; |
| case _SC_THREAD_STACK_MIN: return PTHREAD_STACK_MIN; |
| case _SC_THREAD_THREADS_MAX: return -1; // No specific limit. |
| case _SC_TTY_NAME_MAX: return TTY_NAME_MAX; |
| case _SC_THREADS: return _POSIX_THREADS; |
| case _SC_THREAD_ATTR_STACKADDR: return _POSIX_THREAD_ATTR_STACKADDR; |
| case _SC_THREAD_ATTR_STACKSIZE: return _POSIX_THREAD_ATTR_STACKSIZE; |
| case _SC_THREAD_PRIORITY_SCHEDULING: return _POSIX_THREAD_PRIORITY_SCHEDULING; |
| case _SC_THREAD_PRIO_INHERIT: return _POSIX_THREAD_PRIO_INHERIT; |
| case _SC_THREAD_PRIO_PROTECT: return _POSIX_THREAD_PRIO_PROTECT; |
| case _SC_THREAD_SAFE_FUNCTIONS: return _POSIX_THREAD_SAFE_FUNCTIONS; |
| case _SC_MONOTONIC_CLOCK: return _POSIX_MONOTONIC_CLOCK; |
| |
| case _SC_2_PBS: return -1; // Obsolescent in POSIX.1-2008. |
| case _SC_2_PBS_ACCOUNTING: return -1; // Obsolescent in POSIX.1-2008. |
| case _SC_2_PBS_CHECKPOINT: return -1; // Obsolescent in POSIX.1-2008. |
| case _SC_2_PBS_LOCATE: return -1; // Obsolescent in POSIX.1-2008. |
| case _SC_2_PBS_MESSAGE: return -1; // Obsolescent in POSIX.1-2008. |
| case _SC_2_PBS_TRACK: return -1; // Obsolescent in POSIX.1-2008. |
| case _SC_ADVISORY_INFO: return _POSIX_ADVISORY_INFO; |
| case _SC_BARRIERS: return _POSIX_BARRIERS; |
| case _SC_CLOCK_SELECTION: return _POSIX_CLOCK_SELECTION; |
| case _SC_CPUTIME: return _POSIX_CPUTIME; |
| |
| case _SC_HOST_NAME_MAX: return _POSIX_HOST_NAME_MAX; // Minimum requirement. |
| case _SC_IPV6: return _POSIX_IPV6; |
| case _SC_RAW_SOCKETS: return _POSIX_RAW_SOCKETS; |
| case _SC_READER_WRITER_LOCKS: return _POSIX_READER_WRITER_LOCKS; |
| case _SC_REGEXP: return _POSIX_REGEXP; |
| case _SC_SHELL: return _POSIX_SHELL; |
| case _SC_SPAWN: return _POSIX_SPAWN; |
| case _SC_SPIN_LOCKS: return _POSIX_SPIN_LOCKS; |
| case _SC_SPORADIC_SERVER: return _POSIX_SPORADIC_SERVER; |
| case _SC_SS_REPL_MAX: return -1; |
| case _SC_SYMLOOP_MAX: return _POSIX_SYMLOOP_MAX; // Minimum requirement. |
| case _SC_THREAD_CPUTIME: return _POSIX_THREAD_CPUTIME; |
| |
| case _SC_THREAD_PROCESS_SHARED: return _POSIX_THREAD_PROCESS_SHARED; |
| case _SC_THREAD_ROBUST_PRIO_INHERIT: return _POSIX_THREAD_ROBUST_PRIO_INHERIT; |
| case _SC_THREAD_ROBUST_PRIO_PROTECT: return _POSIX_THREAD_ROBUST_PRIO_PROTECT; |
| case _SC_THREAD_SPORADIC_SERVER: return _POSIX_THREAD_SPORADIC_SERVER; |
| case _SC_TIMEOUTS: return _POSIX_TIMEOUTS; |
| case _SC_TRACE: return -1; |
| case _SC_TRACE_EVENT_FILTER: return -1; |
| case _SC_TRACE_EVENT_NAME_MAX: return -1; |
| case _SC_TRACE_INHERIT: return -1; |
| case _SC_TRACE_LOG: return -1; |
| case _SC_TRACE_NAME_MAX: return -1; |
| case _SC_TRACE_SYS_MAX: return -1; |
| case _SC_TRACE_USER_EVENT_MAX: return -1; |
| case _SC_TYPED_MEMORY_OBJECTS: return _POSIX_TYPED_MEMORY_OBJECTS; |
| case _SC_V7_ILP32_OFF32: return _POSIX_V7_ILP32_OFF32; |
| case _SC_V7_ILP32_OFFBIG: return _POSIX_V7_ILP32_OFFBIG; |
| case _SC_V7_LP64_OFF64: return _POSIX_V7_LP64_OFF64; |
| case _SC_V7_LPBIG_OFFBIG: return _POSIX_V7_LPBIG_OFFBIG; |
| case _SC_XOPEN_STREAMS: return -1; |
| case _SC_XOPEN_UUCP: return -1; |
| |
| case _SC_LEVEL1_ICACHE_SIZE: return __sysconf_caches()->l1_i.size; |
| case _SC_LEVEL1_ICACHE_ASSOC: return __sysconf_caches()->l1_i.assoc; |
| case _SC_LEVEL1_ICACHE_LINESIZE: return __sysconf_caches()->l1_i.linesize; |
| case _SC_LEVEL1_DCACHE_SIZE: return __sysconf_caches()->l1_d.size; |
| case _SC_LEVEL1_DCACHE_ASSOC: return __sysconf_caches()->l1_d.assoc; |
| case _SC_LEVEL1_DCACHE_LINESIZE: return __sysconf_caches()->l1_d.linesize; |
| case _SC_LEVEL2_CACHE_SIZE: return __sysconf_caches()->l2.size; |
| case _SC_LEVEL2_CACHE_ASSOC: return __sysconf_caches()->l2.assoc; |
| case _SC_LEVEL2_CACHE_LINESIZE: return __sysconf_caches()->l2.linesize; |
| case _SC_LEVEL3_CACHE_SIZE: return __sysconf_caches()->l3.size; |
| case _SC_LEVEL3_CACHE_ASSOC: return __sysconf_caches()->l3.assoc; |
| case _SC_LEVEL3_CACHE_LINESIZE: return __sysconf_caches()->l3.linesize; |
| case _SC_LEVEL4_CACHE_SIZE: return __sysconf_caches()->l4.size; |
| case _SC_LEVEL4_CACHE_ASSOC: return __sysconf_caches()->l4.assoc; |
| case _SC_LEVEL4_CACHE_LINESIZE: return __sysconf_caches()->l4.linesize; |
| |
| default: |
| errno = EINVAL; |
| return -1; |
| } |
| } |
