posix: sysconf: match _SC* defines with newlib/picolib

It's possible for newlib/picolib libc libraries to
internally call sysconf() which would execute zephyr's
implementation.  However, if the _SC* defines do not have
matching values, then the incorrect switch case executes.

This issue arises when using newlib/picolib libc that includes
sysconf implementation for ARM.  With current defaults, the
zephyr sysconf() overrides the original libc sysconf() so
we must ensure proper operation.

For Full Sysconf implementation, we will switch to the #define
list just like newlib/picolib, but furthermore, we will try
to reference their unistd.h and use their values when available.

Signed-off-by: Nicholas Lowell <[email protected]>

Author: Nicholas Lowell

include/zephyr/posix/sys/sysconf.h

@@ -7,139 +7,177 @@
 #ifndef ZEPHYR_INCLUDE_POSIX_SYS_SYSCONF_H_
 #define ZEPHYR_INCLUDE_POSIX_SYS_SYSCONF_H_
 
+#include <zephyr/posix/pthread.h>
 #include <zephyr/sys/util_macro.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-enum {
-	_SC_ADVISORY_INFO,
-	_SC_ASYNCHRONOUS_IO,
-	_SC_BARRIERS,
-	_SC_CLOCK_SELECTION,
-	_SC_CPUTIME,
-	_SC_FSYNC,
-	_SC_IPV6,
-	_SC_JOB_CONTROL,
-	_SC_MAPPED_FILES,
-	_SC_MEMLOCK,
-	_SC_MEMLOCK_RANGE,
-	_SC_MEMORY_PROTECTION,
-	_SC_MESSAGE_PASSING,
-	_SC_MONOTONIC_CLOCK,
-	_SC_PRIORITIZED_IO,
-	_SC_PRIORITY_SCHEDULING,
-	_SC_RAW_SOCKETS,
-	_SC_RE_DUP_MAX,
-	_SC_READER_WRITER_LOCKS,
-	_SC_REALTIME_SIGNALS,
-	_SC_REGEXP,
-	_SC_SAVED_IDS,
-	_SC_SEMAPHORES,
-	_SC_SHARED_MEMORY_OBJECTS,
-	_SC_SHELL,
-	_SC_SPAWN,
-	_SC_SPIN_LOCKS,
-	_SC_SPORADIC_SERVER,
-	_SC_SS_REPL_MAX,
-	_SC_SYNCHRONIZED_IO,
-	_SC_THREAD_ATTR_STACKADDR,
-	_SC_THREAD_ATTR_STACKSIZE,
-	_SC_THREAD_CPUTIME,
-	_SC_THREAD_PRIO_INHERIT,
-	_SC_THREAD_PRIO_PROTECT,
-	_SC_THREAD_PRIORITY_SCHEDULING,
-	_SC_THREAD_PROCESS_SHARED,
-	_SC_THREAD_ROBUST_PRIO_INHERIT,
-	_SC_THREAD_ROBUST_PRIO_PROTECT,
-	_SC_THREAD_SAFE_FUNCTIONS,
-	_SC_THREAD_SPORADIC_SERVER,
-	_SC_THREADS,
-	_SC_TIMEOUTS,
-	_SC_TIMERS,
-	_SC_TRACE,
-	_SC_TRACE_EVENT_FILTER,
-	_SC_TRACE_EVENT_NAME_MAX,
-	_SC_TRACE_INHERIT,
-	_SC_TRACE_LOG,
-	_SC_TRACE_NAME_MAX,
-	_SC_TRACE_SYS_MAX,
-	_SC_TRACE_USER_EVENT_MAX,
-	_SC_TYPED_MEMORY_OBJECTS,
-	_SC_VERSION,
-	_SC_V7_ILP32_OFF32,
-	_SC_V7_ILP32_OFFBIG,
-	_SC_V7_LP64_OFF64,
-	_SC_V7_LPBIG_OFFBIG,
-	_SC_V6_ILP32_OFF32,
-	_SC_V6_ILP32_OFFBIG,
-	_SC_V6_LP64_OFF64,
-	_SC_V6_LPBIG_OFFBIG,
-	_SC_BC_BASE_MAX,
-	_SC_BC_DIM_MAX,
-	_SC_BC_SCALE_MAX,
-	_SC_BC_STRING_MAX,
-	_SC_2_C_BIND,
-	_SC_2_C_DEV,
-	_SC_2_CHAR_TERM,
-	_SC_COLL_WEIGHTS_MAX,
-	_SC_DELAYTIMER_MAX,
-	_SC_EXPR_NEST_MAX,
-	_SC_2_FORT_DEV,
-	_SC_2_FORT_RUN,
-	_SC_LINE_MAX,
-	_SC_2_LOCALEDEF,
-	_SC_2_PBS,
-	_SC_2_PBS_ACCOUNTING,
-	_SC_2_PBS_CHECKPOINT,
-	_SC_2_PBS_LOCATE,
-	_SC_2_PBS_MESSAGE,
-	_SC_2_PBS_TRACK,
-	_SC_2_SW_DEV,
-	_SC_2_UPE,
-	_SC_2_VERSION,
-	_SC_XOPEN_CRYPT,
-	_SC_XOPEN_ENH_I18N,
-	_SC_XOPEN_REALTIME,
-	_SC_XOPEN_REALTIME_THREADS,
-	_SC_XOPEN_SHM,
-	_SC_XOPEN_STREAMS,
-	_SC_XOPEN_UNIX,
-	_SC_XOPEN_UUCP,
-	_SC_XOPEN_VERSION,
-	_SC_CLK_TCK,
-	_SC_GETGR_R_SIZE_MAX,
-	_SC_GETPW_R_SIZE_MAX,
-	_SC_AIO_LISTIO_MAX,
-	_SC_AIO_MAX,
-	_SC_AIO_PRIO_DELTA_MAX,
-	_SC_ARG_MAX,
-	_SC_ATEXIT_MAX,
-	_SC_CHILD_MAX,
-	_SC_HOST_NAME_MAX,
-	_SC_IOV_MAX,
-	_SC_LOGIN_NAME_MAX,
-	_SC_NGROUPS_MAX,
-	_SC_MQ_OPEN_MAX,
-	_SC_MQ_PRIO_MAX,
-	_SC_OPEN_MAX,
-	_SC_PAGE_SIZE,
-	_SC_PAGESIZE,
-	_SC_THREAD_DESTRUCTOR_ITERATIONS,
-	_SC_THREAD_KEYS_MAX,
-	_SC_THREAD_STACK_MIN,
-	_SC_THREAD_THREADS_MAX,
-	_SC_RTSIG_MAX,
-	_SC_SEM_NSEMS_MAX,
-	_SC_SEM_VALUE_MAX,
-	_SC_SIGQUEUE_MAX,
-	_SC_STREAM_MAX,
-	_SC_SYMLOOP_MAX,
-	_SC_TIMER_MAX,
-	_SC_TTY_NAME_MAX,
-	_SC_TZNAME_MAX,
-};
+#ifdef CONFIG_POSIX_SYSCONF_IMPL_FULL
+#ifndef _SC_ARG_MAX /* Assume if this is defined, so are the others */
+/* Values assigned are intended to match the values assigned in newlib and picolib
+ * Even though the POSIX standard does not require specific values, this seems to be
+ * required for proper sysconf() operation when called from within newlib/picolib itself.
+ */
+#define _SC_ARG_MAX                      0
+#define _SC_CHILD_MAX                    1
+#define _SC_CLK_TCK                      2
+#define _SC_NGROUPS_MAX                  3
+#define _SC_OPEN_MAX                     4
+#define _SC_JOB_CONTROL                  5
+#define _SC_SAVED_IDS                    6
+#define _SC_VERSION                      7
+#define _SC_PAGESIZE                     8
+#define _SC_PAGE_SIZE                    _SC_PAGESIZE
+/* These are non-POSIX values we accidentally introduced in 2000 without
+ * guarding them.  Keeping them unguarded for backward compatibility.
+ */
+#define _SC_NPROCESSORS_CONF             9
+#define _SC_NPROCESSORS_ONLN             10
+#define _SC_PHYS_PAGES                   11
+#define _SC_AVPHYS_PAGES                 12
+/* End of non-POSIX values. */
+#define _SC_MQ_OPEN_MAX                  13
+#define _SC_MQ_PRIO_MAX                  14
+#define _SC_RTSIG_MAX                    15
+#define _SC_SEM_NSEMS_MAX                16
+#define _SC_SEM_VALUE_MAX                17
+#define _SC_SIGQUEUE_MAX                 18
+#define _SC_TIMER_MAX                    19
+#define _SC_TZNAME_MAX                   20
+#define _SC_ASYNCHRONOUS_IO              21
+#define _SC_FSYNC                        22
+#define _SC_MAPPED_FILES                 23
+#define _SC_MEMLOCK                      24
+#define _SC_MEMLOCK_RANGE                25
+#define _SC_MEMORY_PROTECTION            26
+#define _SC_MESSAGE_PASSING              27
+#define _SC_PRIORITIZED_IO               28
+#define _SC_REALTIME_SIGNALS             29
+#define _SC_SEMAPHORES                   30
+#define _SC_SHARED_MEMORY_OBJECTS        31
+#define _SC_SYNCHRONIZED_IO              32
+#define _SC_TIMERS                       33
+#define _SC_AIO_LISTIO_MAX               34
+#define _SC_AIO_MAX                      35
+#define _SC_AIO_PRIO_DELTA_MAX           36
+#define _SC_DELAYTIMER_MAX               37
+#define _SC_THREAD_KEYS_MAX              38
+#define _SC_THREAD_STACK_MIN             39
+#define _SC_THREAD_THREADS_MAX           40
+#define _SC_TTY_NAME_MAX                 41
+#define _SC_THREADS                      42
+#define _SC_THREAD_ATTR_STACKADDR        43
+#define _SC_THREAD_ATTR_STACKSIZE        44
+#define _SC_THREAD_PRIORITY_SCHEDULING   45
+#define _SC_THREAD_PRIO_INHERIT          46
+/* _SC_THREAD_PRIO_PROTECT was _SC_THREAD_PRIO_CEILING in early drafts */
+#define _SC_THREAD_PRIO_PROTECT          47
+#define _SC_THREAD_PRIO_CEILING          _SC_THREAD_PRIO_PROTECT
+#define _SC_THREAD_PROCESS_SHARED        48
+#define _SC_THREAD_SAFE_FUNCTIONS        49
+#define _SC_GETGR_R_SIZE_MAX             50
+#define _SC_GETPW_R_SIZE_MAX             51
+#define _SC_LOGIN_NAME_MAX               52
+#define _SC_THREAD_DESTRUCTOR_ITERATIONS 53
+#define _SC_ADVISORY_INFO                54
+#define _SC_ATEXIT_MAX                   55
+#define _SC_BARRIERS                     56
+#define _SC_BC_BASE_MAX                  57
+#define _SC_BC_DIM_MAX                   58
+#define _SC_BC_SCALE_MAX                 59
+#define _SC_BC_STRING_MAX                60
+#define _SC_CLOCK_SELECTION              61
+#define _SC_COLL_WEIGHTS_MAX             62
+#define _SC_CPUTIME                      63
+#define _SC_EXPR_NEST_MAX                64
+#define _SC_HOST_NAME_MAX                65
+#define _SC_IOV_MAX                      66
+#define _SC_IPV6                         67
+#define _SC_LINE_MAX                     68
+#define _SC_MONOTONIC_CLOCK              69
+#define _SC_RAW_SOCKETS                  70
+#define _SC_READER_WRITER_LOCKS          71
+#define _SC_REGEXP                       72
+#define _SC_RE_DUP_MAX                   73
+#define _SC_SHELL                        74
+#define _SC_SPAWN                        75
+#define _SC_SPIN_LOCKS                   76
+#define _SC_SPORADIC_SERVER              77
+#define _SC_SS_REPL_MAX                  78
+#define _SC_SYMLOOP_MAX                  79
+#define _SC_THREAD_CPUTIME               80
+#define _SC_THREAD_SPORADIC_SERVER       81
+#define _SC_TIMEOUTS                     82
+#define _SC_TRACE                        83
+#define _SC_TRACE_EVENT_FILTER           84
+#define _SC_TRACE_EVENT_NAME_MAX         85
+#define _SC_TRACE_INHERIT                86
+#define _SC_TRACE_LOG                    87
+#define _SC_TRACE_NAME_MAX               88
+#define _SC_TRACE_SYS_MAX                89
+#define _SC_TRACE_USER_EVENT_MAX         90
+#define _SC_TYPED_MEMORY_OBJECTS         91
+#define _SC_V7_ILP32_OFF32               92
+#define _SC_V6_ILP32_OFF32               _SC_V7_ILP32_OFF32
+#define _SC_XBS5_ILP32_OFF32             _SC_V7_ILP32_OFF32
+#define _SC_V7_ILP32_OFFBIG              93
+#define _SC_V6_ILP32_OFFBIG              _SC_V7_ILP32_OFFBIG
+#define _SC_XBS5_ILP32_OFFBIG            _SC_V7_ILP32_OFFBIG
+#define _SC_V7_LP64_OFF64                94
+#define _SC_V6_LP64_OFF64                _SC_V7_LP64_OFF64
+#define _SC_XBS5_LP64_OFF64              _SC_V7_LP64_OFF64
+#define _SC_V7_LPBIG_OFFBIG              95
+#define _SC_V6_LPBIG_OFFBIG              _SC_V7_LPBIG_OFFBIG
+#define _SC_XBS5_LPBIG_OFFBIG            _SC_V7_LPBIG_OFFBIG
+#define _SC_XOPEN_CRYPT                  96
+#define _SC_XOPEN_ENH_I18N               97
+#define _SC_XOPEN_LEGACY                 98
+#define _SC_XOPEN_REALTIME               99
+#define _SC_STREAM_MAX                   100
+#define _SC_PRIORITY_SCHEDULING          101
+#define _SC_XOPEN_REALTIME_THREADS       102
+#define _SC_XOPEN_SHM                    103
+#define _SC_XOPEN_STREAMS                104
+#define _SC_XOPEN_UNIX                   105
+#define _SC_XOPEN_VERSION                106
+#define _SC_2_CHAR_TERM                  107
+#define _SC_2_C_BIND                     108
+#define _SC_2_C_DEV                      109
+#define _SC_2_FORT_DEV                   110
+#define _SC_2_FORT_RUN                   111
+#define _SC_2_LOCALEDEF                  112
+#define _SC_2_PBS                        113
+#define _SC_2_PBS_ACCOUNTING             114
+#define _SC_2_PBS_CHECKPOINT             115
+#define _SC_2_PBS_LOCATE                 116
+#define _SC_2_PBS_MESSAGE                117
+#define _SC_2_PBS_TRACK                  118
+#define _SC_2_SW_DEV                     119
+#define _SC_2_UPE                        120
+#define _SC_2_VERSION                    121
+#define _SC_THREAD_ROBUST_PRIO_INHERIT   122
+#define _SC_THREAD_ROBUST_PRIO_PROTECT   123
+#define _SC_XOPEN_UUCP                   124
+#define _SC_LEVEL1_ICACHE_SIZE           125
+#define _SC_LEVEL1_ICACHE_ASSOC          126
+#define _SC_LEVEL1_ICACHE_LINESIZE       127
+#define _SC_LEVEL1_DCACHE_SIZE           128
+#define _SC_LEVEL1_DCACHE_ASSOC          129
+#define _SC_LEVEL1_DCACHE_LINESIZE       130
+#define _SC_LEVEL2_CACHE_SIZE            131
+#define _SC_LEVEL2_CACHE_ASSOC           132
+#define _SC_LEVEL2_CACHE_LINESIZE        133
+#define _SC_LEVEL3_CACHE_SIZE            134
+#define _SC_LEVEL3_CACHE_ASSOC           135
+#define _SC_LEVEL3_CACHE_LINESIZE        136
+#define _SC_LEVEL4_CACHE_SIZE            137
+#define _SC_LEVEL4_CACHE_ASSOC           138
+#define _SC_LEVEL4_CACHE_LINESIZE        139
+#define _SC_POSIX_26_VERSION             140
+#endif /* ifdef _SC_ARG_MAX */
+#endif /* ifdef CONFIG_POSIX_SYSCONF_IMPL_FULL */
 
 #define __z_posix_sysconf_SC_ADVISORY_INFO (-1L)
 #define __z_posix_sysconf_SC_ASYNCHRONOUS_IO                                                       \

include/zephyr/posix/unistd.h

@@ -6,6 +6,9 @@
 #ifndef ZEPHYR_INCLUDE_POSIX_UNISTD_H_
 #define ZEPHYR_INCLUDE_POSIX_UNISTD_H_
 
+#ifdef CONFIG_POSIX_SYSCONF_IMPL_FULL
+#include_next <unistd.h>
+#endif
 #include <zephyr/posix/posix_types.h>
 
 #ifdef CONFIG_POSIX_API