posix: deprecate POSIX_MAX_FDS and add POSIX_DEVICE_IO

The POSIX_MAX_FDS option does not correspond to any standard
POSIX option. It was used to define the size of the file
descriptor table, which is by no means exclusively used by
POSIX (also net, fs, ...).

POSIX_MAX_FDS is being deprecated in order to ensure that
Zephyr's POSIX Kconfig variables correspond to those defined in
the specification, as of IEEE 1003.1-2017. Namely,
POSIX_OPEN_MAX. CONFIG_POSIX_MAX_OPEN_FILES is being deprecated
for the same reason.

To mitigate any possible layering violations, that option is
not user selectable. It tracks the newly added
CONFIG_ZVFS_OPEN_MAX option, which is native to Zephyr.

With this deprecation, we introduce the following Kconfig
options that map directly to standard POSIX Option Groups by
simply removing "CONFIG_":

* CONFIG_POSIX_DEVICE_IO

Similarly, with this deprecation, we introduce the following
Kconfig options that map directly to standard POSIX Options by
simply removing "CONFIG":

* CONFIG_POSIX_OPEN_MAX

In order to maintain parity with the current feature set, we
introduce the following Kconfig options.

* CONFIG_POSIX_DEVICE_IO_ALIAS_CLOSE
* CONFIG_POSIX_DEVICE_IO_ALIAS_OPEN
* CONFIG_POSIX_DEVICE_IO_ALIAS_READ
* CONFIG_POSIX_DEVICE_IO_ALIAS_WRITE

Gate open(), close(), read(), and write() via the
CONFIG_POSIX_DEVICE_IO Kconfig option and move
implementations into device_io.c, to be conformant with the
spec.

Lastly, stage function names for upcoming ZVFS work, to be
completed as part of the LTSv3 Roadmap (e.g. zvfs_open(), ..).

Signed-off-by: Chris Friedt <cfriedt@tenstorrent.com>

doc/connectivity/networking/net_config_guide.rst

@@ -87,7 +87,7 @@ Socket Options
   Maximum number of supported poll() entries. One needs to select proper value here depending
   on how many BSD sockets are polled in the system.
 
-:kconfig:option:`CONFIG_POSIX_MAX_FDS`
+:kconfig:option:`CONFIG_ZVFS_OPEN_MAX`
   Maximum number of open file descriptors, this includes files, sockets, special devices, etc.
   One needs to select proper value here depending on how many BSD sockets are created in
   the system.

doc/services/portability/posix/aep/index.rst

@@ -50,7 +50,7 @@ The *Minimal Realtime System Profile* (PSE51) includes all of the
 
     :ref:`POSIX_C_LANG_JUMP <posix_option_group_c_lang_jump>`, yes,
     :ref:`POSIX_C_LANG_SUPPORT <posix_option_group_c_lang_support>`, yes,
-    :ref:`POSIX_DEVICE_IO <posix_option_group_device_io>`,,
+    :ref:`POSIX_DEVICE_IO <posix_option_group_device_io>`,, :kconfig:option:`CONFIG_POSIX_DEVICE_IO`
     :ref:`POSIX_SIGNALS <posix_option_group_signals>`,,
     :ref:`POSIX_SINGLE_PROCESS <posix_option_group_single_process>`, yes,
     :ref:`POSIX_THREADS_BASE <posix_option_group_threads_base>`, yes,

doc/services/portability/posix/kconfig/index.rst

@@ -25,8 +25,8 @@ implementation of the POSIX API.
 * :kconfig:option:`CONFIG_NET_SOCKETS_POLL_MAX`
 * :kconfig:option:`CONFIG_POSIX_API`
 * :kconfig:option:`CONFIG_POSIX_FS`
-* :kconfig:option:`CONFIG_POSIX_MAX_FDS`
+* :kconfig:option:`CONFIG_ZVFS_OPEN_MAX`
-* :kconfig:option:`CONFIG_POSIX_MAX_OPEN_FILES`
+* :kconfig:option:`CONFIG_POSIX_OPEN_MAX`
 * :kconfig:option:`CONFIG_POSIX_MQUEUE`
 * :kconfig:option:`CONFIG_POSIX_RTSIG_MAX`
 * :kconfig:option:`CONFIG_POSIX_SIGNAL`

drivers/modem/Kconfig

@@ -155,7 +155,7 @@ config MODEM_SOCKET
 	  modem_socket_init().
 	  Note that the modem socket uses runtime allocated file descriptors
 	  reserved from the fdtable, for which the max count is set using the
-	  Kconfig option POSIX_MAX_FDS. Make sure to update this value as both
+	  Kconfig option ZVFS_OPEN_MAX. Make sure to update this value as both
 	  the modem sockets and the POSIX_API, if used, share them.
 
 config MODEM_SOCKET_PACKET_COUNT

include/zephyr/net/socket_select.h

@@ -28,7 +28,7 @@ extern "C" {
 
 /** Socket file descriptor set. */
 typedef struct zsock_fd_set {
-	uint32_t bitset[(CONFIG_POSIX_MAX_FDS + 31) / 32];
+	uint32_t bitset[(CONFIG_ZVFS_OPEN_MAX + 31) / 32];
 } zsock_fd_set;
 
 /**

include/zephyr/posix/posix_features.h

@@ -211,7 +211,7 @@
 #define _POSIX_MQ_PRIO_MAX                  (32)
 #define _POSIX_NAME_MAX                     (14)
 #define _POSIX_NGROUPS_MAX                  (8)
-#define _POSIX_OPEN_MAX                     CONFIG_POSIX_MAX_FDS
+#define _POSIX_OPEN_MAX                     CONFIG_POSIX_OPEN_MAX
 #define _POSIX_PATH_MAX                     (256)
 #define _POSIX_PIPE_BUF                     (512)
 #define _POSIX_RE_DUP_MAX                   (255)

include/zephyr/posix/sys/sysconf.h

@@ -268,7 +268,7 @@ enum {
 #define __z_posix_sysconf_SC_NGROUPS_MAX                  _POSIX_NGROUPS_MAX
 #define __z_posix_sysconf_SC_MQ_OPEN_MAX                  MQ_OPEN_MAX
 #define __z_posix_sysconf_SC_MQ_PRIO_MAX                  MQ_PRIO_MAX
-#define __z_posix_sysconf_SC_OPEN_MAX                     CONFIG_POSIX_MAX_FDS
+#define __z_posix_sysconf_SC_OPEN_MAX                     CONFIG_ZVFS_OPEN_MAX
 #define __z_posix_sysconf_SC_PAGE_SIZE                    PAGE_SIZE
 #define __z_posix_sysconf_SC_PAGESIZE                     PAGESIZE
 #define __z_posix_sysconf_SC_THREAD_DESTRUCTOR_ITERATIONS PTHREAD_DESTRUCTOR_ITERATIONS

lib/libc/Kconfig

@@ -102,6 +102,10 @@ config NEWLIB_LIBC
 	depends on !NATIVE_APPLICATION
 	depends on NEWLIB_LIBC_SUPPORTED
 	select NEED_LIBC_MEM_PARTITION
+	imply POSIX_DEVICE_IO_ALIAS_CLOSE
+	imply POSIX_DEVICE_IO_ALIAS_OPEN
+	imply POSIX_DEVICE_IO_ALIAS_READ
+	imply POSIX_DEVICE_IO_ALIAS_WRITE
 	imply POSIX_FD_MGMT_ALIAS_LSEEK
 	help
 	  Build with newlib library. The newlib library is expected to be

lib/libc/newlib/libc-hooks.c

@@ -23,6 +23,12 @@
 #include <zephyr/kernel/mm.h>
 #include <sys/time.h>
 
+int _read(int fd, void *buf, int nbytes);
+int _write(int fd, const void *buf, int nbytes);
+int _open(const char *name, int mode);
+int _close(int file);
+int _lseek(int file, int ptr, int dir);
+
 #define LIBC_BSS	K_APP_BMEM(z_libc_partition)
 #define LIBC_DATA	K_APP_DMEM(z_libc_partition)
 
@@ -210,8 +216,8 @@ static inline int z_vrfy_zephyr_write_stdout(const void *buf, int nbytes)
 #include <zephyr/syscalls/zephyr_write_stdout_mrsh.c>
 #endif
 
-#ifndef CONFIG_POSIX_API
+#ifndef CONFIG_POSIX_DEVICE_IO
-int _read(int fd, char *buf, int nbytes)
+int _read(int fd, void *buf, int nbytes)
 {
 	ARG_UNUSED(fd);
 
@@ -238,10 +244,7 @@ int _close(int file)
 	return -1;
 }
 __weak FUNC_ALIAS(_close, close, int);
-#else
+#endif /* CONFIG_POSIX_DEVICE_IO */
-extern ssize_t write(int file, const char *buffer, size_t count);
-#define _write	write
-#endif
 
 #ifndef CONFIG_POSIX_FD_MGMT
 int _lseek(int file, int ptr, int dir)
@@ -275,6 +278,7 @@ int _fstat(int file, struct stat *st)
 	return 0;
 }
 __weak FUNC_ALIAS(_fstat, fstat, int);
+#endif /* CONFIG_POSIX_FILE_SYSTEM */
 
 __weak void _exit(int status)
 {
@@ -478,11 +482,6 @@ __weak FUNC_NORETURN void __chk_fail(void)
 }
 
 #if CONFIG_XTENSA
-extern int _read(int fd, char *buf, int nbytes);
-extern int _open(const char *name, int mode);
-extern int _close(int file);
-extern int _lseek(int file, int ptr, int dir);
-
 /* The Newlib in xtensa toolchain has a few missing functions for the
  * reentrant versions of the syscalls.
  */

lib/os/Kconfig

@@ -10,6 +10,15 @@ config FDTABLE
 	  for any I/O object implementing POSIX I/O semantics (i.e. read/write +
 	  aux operations).
 
+config ZVFS_OPEN_MAX
+	int "Maximum number of open file descriptors"
+	default 16 if WIFI_NM_WPA_SUPPLICANT
+	default 16 if POSIX_API
+	default 4
+	help
+	  Maximum number of open file descriptors, this includes
+	  files, sockets, special devices, etc.
+
 config PRINTK_SYNC
 	bool "Serialize printk() calls"
 	default y if SMP && MP_MAX_NUM_CPUS > 1 && !(EFI_CONSOLE && LOG)

lib/os/fdtable.c

@@ -31,12 +31,14 @@ struct fd_entry {
 	struct k_condvar cond;
 };
 
-#ifdef CONFIG_POSIX_API
+#if defined(CONFIG_POSIX_DEVICE_IO)
 static const struct fd_op_vtable stdinout_fd_op_vtable;
-#endif
 
-static struct fd_entry fdtable[CONFIG_POSIX_MAX_FDS] = {
+BUILD_ASSERT(CONFIG_ZVFS_OPEN_MAX >= 3, "CONFIG_ZVFS_OPEN_MAX >= 3 for CONFIG_POSIX_DEVICE_IO");
-#ifdef CONFIG_POSIX_API
+#endif /* defined(CONFIG_POSIX_DEVICE_IO) */
+
+static struct fd_entry fdtable[CONFIG_ZVFS_OPEN_MAX] = {
+#if defined(CONFIG_POSIX_DEVICE_IO)
 	/*
 	 * Predefine entries for stdin/stdout/stderr.
 	 */
@@ -62,9 +64,7 @@ static struct fd_entry fdtable[CONFIG_POSIX_MAX_FDS] = {
 		.cond = Z_CONDVAR_INITIALIZER(fdtable[2].cond),
 	},
 #else
-	{
+	{0},
-	0
-	},
 #endif
 };
 
@@ -296,9 +296,7 @@ int z_alloc_fd(void *obj, const struct fd_op_vtable *vtable)
 	return fd;
 }
 
-#ifdef CONFIG_POSIX_API
+ssize_t zvfs_read(int fd, void *buf, size_t sz)
-
-ssize_t read(int fd, void *buf, size_t sz)
 {
 	ssize_t res;
 
@@ -314,9 +312,8 @@ ssize_t read(int fd, void *buf, size_t sz)
 
 	return res;
 }
-FUNC_ALIAS(read, _read, ssize_t);
 
-ssize_t write(int fd, const void *buf, size_t sz)
+ssize_t zvfs_write(int fd, const void *buf, size_t sz)
 {
 	ssize_t res;
 
@@ -332,9 +329,8 @@ ssize_t write(int fd, const void *buf, size_t sz)
 
 	return res;
 }
-FUNC_ALIAS(write, _write, ssize_t);
 
-int close(int fd)
+int zvfs_close(int fd)
 {
 	int res;
 
@@ -352,7 +348,6 @@ int close(int fd)
 
 	return res;
 }
-FUNC_ALIAS(close, _close, int);
 
 #ifdef CONFIG_POSIX_FSYNC
 int fsync(int fd)
@@ -372,8 +367,8 @@ off_t zvfs_lseek(int fd, off_t offset, int whence)
 		return -1;
 	}
 
-	return z_fdtable_call_ioctl(fdtable[fd].vtable, fdtable[fd].obj, ZFD_IOCTL_LSEEK,
+	return z_fdtable_call_ioctl(fdtable[fd].vtable, fdtable[fd].obj, ZFD_IOCTL_LSEEK, offset,
-			  offset, whence);
+				    whence);
 }
 
 int ioctl(int fd, unsigned long request, ...)
@@ -406,6 +401,7 @@ int zvfs_fcntl(int fd, int cmd, va_list args)
 	return res;
 }
 
+#if defined(CONFIG_POSIX_DEVICE_IO)
 /*
  * fd operations for stdio/stdout/stderr
  */
@@ -420,7 +416,7 @@ static ssize_t stdinout_read_vmeth(void *obj, void *buffer, size_t count)
 static ssize_t stdinout_write_vmeth(void *obj, const void *buffer, size_t count)
 {
 #if defined(CONFIG_BOARD_NATIVE_POSIX)
-	return write(1, buffer, count);
+	return zvfs_write(1, buffer, count);
 #elif defined(CONFIG_NEWLIB_LIBC) || defined(CONFIG_ARCMWDT_LIBC)
 	return z_impl_zephyr_write_stdout(buffer, count);
 #else
@@ -441,4 +437,4 @@ static const struct fd_op_vtable stdinout_fd_op_vtable = {
 	.ioctl = stdinout_ioctl_vmeth,
 };
 
-#endif /* CONFIG_POSIX_API */
+#endif /* defined(CONFIG_POSIX_DEVICE_IO) */

lib/posix/options/CMakeLists.txt

@@ -37,9 +37,13 @@ add_subdirectory_ifdef(CONFIG_GETOPT getopt)
 zephyr_library_sources_ifdef(CONFIG_EVENTFD eventfd.c)
 zephyr_library_sources_ifdef(CONFIG_FNMATCH fnmatch.c)
 zephyr_library_sources_ifdef(CONFIG_GETENTROPY getentropy.c)
-zephyr_library_sources_ifdef(CONFIG_POSIX_API perror.c)
 zephyr_library_sources_ifdef(CONFIG_POSIX_ASYNCHRONOUS_IO aio.c)
 zephyr_library_sources_ifdef(CONFIG_POSIX_CONFSTR confstr.c)
+zephyr_library_sources_ifdef(CONFIG_POSIX_DEVICE_IO
+  # perror should be moved to the common libc
+  perror.c
+  device_io.c
+)
 zephyr_library_sources_ifdef(CONFIG_POSIX_ENV env.c)
 zephyr_library_sources_ifdef(CONFIG_POSIX_FD_MGMT
   fd_mgmt.c

lib/posix/options/Kconfig

@@ -27,9 +27,9 @@ rsource "Kconfig.aio"
 rsource "Kconfig.barrier"
 rsource "Kconfig.cond"
 rsource "Kconfig.confstr"
+rsource "Kconfig.device_io"
 rsource "Kconfig.env"
 rsource "Kconfig.eventfd"
-rsource "Kconfig.fdtable"
 rsource "Kconfig.fd_mgmt"
 rsource "Kconfig.fnmatch"
 rsource "Kconfig.fs"

lib/posix/options/Kconfig.deprecated

@@ -37,6 +37,26 @@ config POSIX_LIMITS_RTSIG_MAX
 
 	  Please use CONFIG_POSIX_RTSIG_MAX instead.
 
+config POSIX_MAX_FDS
+	int "Maximum number of open file descriptors [DEPRECATED]"
+	default POSIX_OPEN_MAX
+	help
+	  This option is deprecated.
+
+	  Please use CONFIG_POSIX_OPEN_MAX instead.
+
+	  See also CONFIG_ZVFS_OPEN_MAX.
+
+config POSIX_MAX_OPEN_FILES
+	int "Maximum number of open file descriptors [DEPRECATED]"
+	default POSIX_OPEN_MAX
+	help
+	  This option is deprecated.
+
+	  Please use CONFIG_POSIX_OPEN_MAX instead.
+
+	  See also CONFIG_ZVFS_OPEN_MAX.
+
 config TIMER
 	bool "Timer support [DEPRECATED]"
 	select DEPRECATED

lib/posix/options/Kconfig.device_io

@@ -0,0 +1,57 @@
+# Copyright (c) 2024 Tenstorrent AI ULC
+#
+# SPDX-License-Identifier: Apache-2.0
+
+menu "POSIX device I/O"
+
+config POSIX_DEVICE_IO
+	bool "POSIX device I/O [EXPERIMENTAL]"
+	default y if POSIX_API
+	select FDTABLE
+	select EXPERIMENTAL
+	help
+	  Select 'y' here and Zephyr will provide an implementation of the POSIX_DEVICE_IO Option
+	  Group such as FD_CLR(), FD_ISSET(), FD_SET(), FD_ZERO(), close(), fdopen(), fileno(), open(),
+	  poll(), pread(), pselect(), pwrite(), read(), select(), and write().
+
+	  For more informnation, please see
+	  https://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_subprofiles.html
+
+if POSIX_DEVICE_IO
+
+# These options are intended to be used for compatibility with external POSIX
+# implementations such as those in Newlib or Picolibc.
+
+config POSIX_DEVICE_IO_ALIAS_CLOSE
+	bool
+	help
+	  Select 'y' here and Zephyr will provide an alias for close() as _close().
+
+config POSIX_DEVICE_IO_ALIAS_OPEN
+	bool
+	help
+	  Select 'y' here and Zephyr will provide an alias for open() as _open().
+
+config POSIX_DEVICE_IO_ALIAS_READ
+	bool
+	help
+	  Select 'y' here and Zephyr will provide an alias for read() as _read().
+
+config POSIX_DEVICE_IO_ALIAS_WRITE
+	bool
+	help
+	  Select 'y' here and Zephyr will provide an alias for write() as _write().
+
+endif # POSIX_DEVICE_IO
+
+config POSIX_OPEN_MAX
+	int
+	default ZVFS_OPEN_MAX
+	help
+	  The maximum number of files that a process can have open at one time. This option is not
+	  directly user-configurable but can be adjusted via CONFIG_ZVFS_OPEN_MAX.
+
+	  For more information, please see
+	  https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/limits.h.html
+
+endmenu

lib/posix/options/Kconfig.fdtable

@@ -1,16 +0,0 @@
-# Copyright (c) 2018 Linaro
-#
-# SPDX-License-Identifier: Apache-2.0
-
-menu "File descriptor table options"
-
-config POSIX_MAX_FDS
-	int "Maximum number of open file descriptors"
-	default 16 if WIFI_NM_WPA_SUPPLICANT
-	default 16 if POSIX_API
-	default 4
-	help
-	  Maximum number of open file descriptors, this includes
-	  files, sockets, special devices, etc.
-
-endmenu # "File descriptor table options"

lib/posix/options/Kconfig.fs

@@ -12,13 +12,6 @@ menuconfig POSIX_FS
 
 if POSIX_FS
 
-config POSIX_MAX_OPEN_FILES
-	int "Maximum number of open file descriptors"
-	default 16
-	help
-	  Maximum number of open files. Note that this setting
-	  is additionally bounded by CONFIG_POSIX_MAX_FDS.
-
 config POSIX_FSYNC
 	bool "Support for fsync()"
 	default y

lib/posix/options/device_io.c

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2024, Tenstorrent AI ULC
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <zephyr/posix/poll.h>
+#include <zephyr/posix/unistd.h>
+#include <zephyr/posix/sys/select.h>
+#include <zephyr/posix/sys/socket.h>
+
+/* prototypes for external, not-yet-public, functions in fdtable.c or fs.c */
+int zvfs_close(int fd);
+int zvfs_open(const char *name, int flags);
+ssize_t zvfs_read(int fd, void *buf, size_t sz);
+ssize_t zvfs_write(int fd, const void *buf, size_t sz);
+
+int close(int fd)
+{
+	return zvfs_close(fd);
+}
+#ifdef CONFIG_POSIX_DEVICE_IO_ALIAS_CLOSE
+FUNC_ALIAS(close, _close, int);
+#endif
+
+int open(const char *name, int flags, ...)
+{
+	/* FIXME: necessarily need to check for O_CREAT and unpack ... if set */
+	return zvfs_open(name, flags);
+}
+#ifdef CONFIG_POSIX_DEVICE_IO_ALIAS_OPEN
+FUNC_ALIAS(open, _open, int);
+#endif
+
+int poll(struct pollfd *fds, int nfds, int timeout)
+{
+	/* TODO: create  zvfs_poll() and dispatch to subsystems based on file type */
+	return zsock_poll(fds, nfds, timeout);
+}
+
+ssize_t read(int fd, void *buf, size_t sz)
+{
+	return zvfs_read(fd, buf, sz);
+}
+#ifdef CONFIG_POSIX_DEVICE_IO_ALIAS_READ
+FUNC_ALIAS(read, _read, ssize_t);
+#endif
+
+int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout)
+{
+	/* TODO: create  zvfs_select() and dispatch to subsystems based on file type */
+	return zsock_select(nfds, readfds, writefds, exceptfds, (struct zsock_timeval *)timeout);
+}
+
+ssize_t write(int fd, const void *buf, size_t sz)
+{
+	return zvfs_write(fd, buf, sz);
+}
+#ifdef CONFIG_POSIX_DEVICE_IO_ALIAS_WRITE
+FUNC_ALIAS(write, _write, ssize_t);
+#endif

lib/posix/options/fs.c

@@ -26,7 +26,7 @@ struct posix_fs_desc {
 	bool used;
 };
 
-static struct posix_fs_desc desc_array[CONFIG_POSIX_MAX_OPEN_FILES];
+static struct posix_fs_desc desc_array[CONFIG_POSIX_OPEN_MAX];
 
 static struct fs_dirent fdirent;
 static struct dirent pdirent;
@@ -39,7 +39,7 @@ static struct posix_fs_desc *posix_fs_alloc_obj(bool is_dir)
 	struct posix_fs_desc *ptr = NULL;
 	unsigned int key = irq_lock();
 
-	for (i = 0; i < CONFIG_POSIX_MAX_OPEN_FILES; i++) {
+	for (i = 0; i < CONFIG_POSIX_OPEN_MAX; i++) {
 		if (desc_array[i].used == false) {
 			ptr = &desc_array[i];
 			ptr->used = true;
@@ -80,12 +80,7 @@ static int posix_mode_to_zephyr(int mf)
 	return mode;
 }
 
-/**
+int zvfs_open(const char *name, int flags)
- * @brief Open a file.
- *
- * See IEEE 1003.1
- */
-int open(const char *name, int flags, ...)
 {
 	int rc, fd;
 	struct posix_fs_desc *ptr = NULL;
@@ -123,10 +118,6 @@ int open(const char *name, int flags, ...)
 	return fd;
 }
 
-#if !defined(CONFIG_NEWLIB_LIBC) && !defined(CONFIG_PICOLIBC)
-FUNC_ALIAS(open, _open, int);
-#endif
-
 static int fs_close_vmeth(void *obj)
 {
 	struct posix_fs_desc *ptr = obj;

lib/posix/options/net.c

@@ -13,8 +13,6 @@
 #include <zephyr/posix/arpa/inet.h>
 #include <zephyr/posix/netinet/in.h>
 #include <zephyr/posix/net/if.h>
-#include <zephyr/posix/poll.h>
-#include <zephyr/posix/sys/select.h>
 #include <zephyr/posix/sys/socket.h>
 
 /* From arpa/inet.h */
@@ -355,11 +353,6 @@ int listen(int sock, int backlog)
 	return zsock_listen(sock, backlog);
 }
 
-int poll(struct pollfd *fds, int nfds, int timeout)
-{
-	return zsock_poll(fds, nfds, timeout);
-}
-
 ssize_t recv(int sock, void *buf, size_t max_len, int flags)
 {
 	return zsock_recv(sock, buf, max_len, flags);
@@ -376,11 +369,6 @@ ssize_t recvmsg(int sock, struct msghdr *msg, int flags)
 	return zsock_recvmsg(sock, msg, flags);
 }
 
-int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout)
-{
-	return zsock_select(nfds, readfds, writefds, exceptfds, (struct zsock_timeval *)timeout);
-}
-
 ssize_t send(int sock, const void *buf, size_t len, int flags)
 {
 	return zsock_send(sock, buf, len, flags);

modules/hostap/Kconfig

@@ -41,7 +41,7 @@ config WIFI_NM_WPA_SUPPLICANT_WQ_PRIO
 	int "Thread priority of wpa_supplicant iface workqueue"
 	default 7
 
-# Currently we default POSIX_MAX_FDS to 16 in lib/posix/Kconfig
+# Currently we default ZVFS_OPEN_MAX to 16 in lib/posix/Kconfig
 # l2_packet - 1
 # ctrl_iface - 2 * socketpairs = 4(local and global)
 # z_wpa_event_sock - 1 socketpair = 2

samples/modules/thrift/hello/client/prj.conf

@@ -28,7 +28,7 @@ CONFIG_NET_TCP=y
 CONFIG_NET_IPV6=n
 CONFIG_NET_IPV4=y
 CONFIG_NET_SOCKETS=y
-CONFIG_POSIX_MAX_FDS=6
+CONFIG_ZVFS_OPEN_MAX=6
 CONFIG_NET_CONNECTION_MANAGER=y
 
 # Kernel options
@@ -61,7 +61,7 @@ CONFIG_NET_CONFIG_PEER_IPV4_ADDR="192.0.2.2"
 
 # Number of socket descriptors might need adjusting
 # if there are more than 1 handlers defined.
-CONFIG_POSIX_MAX_FDS=16
+CONFIG_ZVFS_OPEN_MAX=16
 
 # Some platforms require relatively large stack sizes.
 # This can be tuned per-board.

samples/modules/thrift/hello/server/prj.conf

@@ -51,7 +51,7 @@ CONFIG_NET_CONFIG_PEER_IPV4_ADDR="192.0.2.2"
 
 # Number of socket descriptors might need adjusting
 # if there are more than 1 handlers defined.
-CONFIG_POSIX_MAX_FDS=16
+CONFIG_ZVFS_OPEN_MAX=16
 
 # Some platforms require relatively large stack sizes.
 # This can be tuned per-board.

samples/net/mqtt_sn_publisher/prj.conf

@@ -5,7 +5,7 @@ CONFIG_NET_IPV4=y
 CONFIG_NET_IPV6=n
 CONFIG_NET_SOCKETS=y
 CONFIG_POSIX_API=y
-CONFIG_POSIX_MAX_FDS=6
+CONFIG_ZVFS_OPEN_MAX=6
 CONFIG_NET_CONNECTION_MANAGER=y
 
 # Kernel options

samples/net/sockets/dumb_http_server_mt/prj.conf

@@ -2,7 +2,7 @@
 CONFIG_TEST_RANDOM_GENERATOR=y
 
 # POSIX options
-CONFIG_POSIX_MAX_FDS=20
+CONFIG_ZVFS_OPEN_MAX=20
 CONFIG_POSIX_API=y
 
 # Networking config

samples/net/sockets/echo_client/overlay-tls.conf

@@ -12,4 +12,4 @@ CONFIG_MBEDTLS_SSL_MAX_CONTENT_LEN=2048
 CONFIG_NET_SOCKETS_SOCKOPT_TLS=y
 CONFIG_NET_SOCKETS_TLS_MAX_CONTEXTS=4
 CONFIG_NET_SOCKETS_ENABLE_DTLS=y
-CONFIG_POSIX_MAX_FDS=8
+CONFIG_ZVFS_OPEN_MAX=8

samples/net/sockets/echo_server/overlay-tls.conf

@@ -13,4 +13,4 @@ CONFIG_NET_SOCKETS_SOCKOPT_TLS=y
 CONFIG_NET_SOCKETS_TLS_MAX_CONTEXTS=6
 CONFIG_NET_SOCKETS_ENABLE_DTLS=y
 CONFIG_NET_SOCKETS_DTLS_TIMEOUT=30000
-CONFIG_POSIX_MAX_FDS=16
+CONFIG_ZVFS_OPEN_MAX=16

samples/net/sockets/echo_server/prj.conf

@@ -6,7 +6,7 @@ CONFIG_NET_IPV6=y
 CONFIG_NET_IPV4=y
 CONFIG_NET_SOCKETS=y
 CONFIG_POSIX_API=y
-CONFIG_POSIX_MAX_FDS=6
+CONFIG_ZVFS_OPEN_MAX=6
 CONFIG_NET_CONNECTION_MANAGER=y
 
 # Kernel options
@@ -48,7 +48,7 @@ CONFIG_NET_CONFIG_PEER_IPV4_ADDR="192.0.2.2"
 
 # Number of socket descriptors might need adjusting
 # if there are more than 1 handlers defined.
-CONFIG_POSIX_MAX_FDS=12
+CONFIG_ZVFS_OPEN_MAX=12
 
 # How many client can connect to echo-server simultaneously
 CONFIG_NET_SAMPLE_NUM_HANDLERS=1

samples/net/sockets/echo_service/prj.conf

@@ -10,7 +10,7 @@ CONFIG_NET_IPV6=y
 CONFIG_NET_TCP=y
 CONFIG_NET_SOCKETS=y
 CONFIG_NET_IPV4_MAPPING_TO_IPV6=y
-CONFIG_POSIX_MAX_FDS=10
+CONFIG_ZVFS_OPEN_MAX=10
 CONFIG_NET_MAX_CONN=5
 CONFIG_NET_SOCKETS_SERVICE=y
 CONFIG_NET_SOCKETS_POLL_MAX=20

samples/net/sockets/http_server/prj.conf

@@ -5,7 +5,7 @@ CONFIG_LOG=y
 CONFIG_ENTROPY_GENERATOR=y
 CONFIG_TEST_RANDOM_GENERATOR=y
 CONFIG_INIT_STACKS=y
-CONFIG_POSIX_MAX_FDS=32
+CONFIG_ZVFS_OPEN_MAX=32
 CONFIG_POSIX_API=y
 CONFIG_FDTABLE=y
 CONFIG_NET_SOCKETS_POLL_MAX=32

samples/net/sockets/net_mgmt/prj.conf

@@ -6,7 +6,7 @@ CONFIG_NET_IPV6=y
 CONFIG_NET_IPV4=y
 CONFIG_NET_SOCKETS=y
 CONFIG_POSIX_API=y
-CONFIG_POSIX_MAX_FDS=6
+CONFIG_ZVFS_OPEN_MAX=6
 CONFIG_NET_SOCKETS_NET_MGMT=y
 CONFIG_NET_MGMT_EVENT=y
 

samples/net/sockets/packet/prj.conf

@@ -7,7 +7,7 @@ CONFIG_NET_IPV4=n
 CONFIG_NET_MAX_CONTEXTS=10
 CONFIG_NET_SOCKETS=y
 CONFIG_POSIX_API=y
-CONFIG_POSIX_MAX_FDS=6
+CONFIG_ZVFS_OPEN_MAX=6
 CONFIG_NET_CONTEXT_RCVTIMEO=y
 CONFIG_NET_MGMT=y
 CONFIG_NET_MGMT_EVENT=y

samples/net/zperf/prj.conf

@@ -20,7 +20,7 @@ CONFIG_NET_MAX_CONTEXTS=5
 CONFIG_NET_TC_TX_COUNT=1
 CONFIG_NET_SOCKETS=y
 CONFIG_NET_SOCKETS_POLL_MAX=9
-CONFIG_POSIX_MAX_FDS=8
+CONFIG_ZVFS_OPEN_MAX=8
 CONFIG_POSIX_API=y
 
 CONFIG_INIT_STACKS=y

samples/subsys/video/tcpserversink/prj.conf

@@ -3,7 +3,7 @@ CONFIG_NETWORKING=y
 CONFIG_NET_TCP=y
 CONFIG_NET_IPV4=y
 CONFIG_NET_SOCKETS=y
-CONFIG_POSIX_MAX_FDS=6
+CONFIG_ZVFS_OPEN_MAX=6
 CONFIG_POSIX_API=y
 
 # Kernel options

subsys/net/lib/sockets/socket_obj_core.c

@@ -20,8 +20,8 @@ static K_MUTEX_DEFINE(sock_obj_mutex);
 /* Allocate some extra socket objects so that we can track
  * closed sockets and get some historical statistics.
  */
-static struct sock_obj sock_objects[CONFIG_POSIX_MAX_FDS * 2] = {
+static struct sock_obj sock_objects[CONFIG_ZVFS_OPEN_MAX * 2] = {
-	[0 ... ((CONFIG_POSIX_MAX_FDS * 2) - 1)] = {
+	[0 ... ((CONFIG_ZVFS_OPEN_MAX * 2) - 1)] = {
 		.fd = -1,
 		.init_done = false,
 	}

tests/modules/thrift/ThriftTest/overlay-tls.conf

@@ -14,7 +14,7 @@ CONFIG_THRIFT_SSL_SOCKET=y
 # tcp sockets (client, server): 2
 # tls sockets (client, server): 2
 # socketpairs for cancellation (accept, client, server): 6
-CONFIG_POSIX_MAX_FDS=15
+CONFIG_ZVFS_OPEN_MAX=15
 
 # TLS configuration
 CONFIG_MBEDTLS=y

tests/modules/thrift/ThriftTest/prj.conf

@@ -51,7 +51,7 @@ CONFIG_NET_PKT_RX_COUNT=20
 # stdin, stdout, stderr: 3
 # socketpair for channel: 2
 # eventfd for cancellation: 1
-CONFIG_POSIX_MAX_FDS=6
+CONFIG_ZVFS_OPEN_MAX=6
 
 # Network address config
 CONFIG_NET_IPV4=y

tests/net/lib/dns_resolve/prj.conf

@@ -30,4 +30,4 @@ CONFIG_ZTEST=y
 
 CONFIG_MAIN_STACK_SIZE=1344
 CONFIG_NET_SOCKETS_POLL_MAX=9
-CONFIG_POSIX_MAX_FDS=8
+CONFIG_ZVFS_OPEN_MAX=8

tests/net/lib/http_server/crime/prj.conf

@@ -9,7 +9,7 @@ CONFIG_ENTROPY_GENERATOR=y
 CONFIG_TEST_RANDOM_GENERATOR=y
 CONFIG_ZTEST_STACK_SIZE=1024
 
-CONFIG_POSIX_MAX_FDS=10
+CONFIG_ZVFS_OPEN_MAX=10
 CONFIG_REQUIRES_FULL_LIBC=y
 CONFIG_EVENTFD_MAX=10
 CONFIG_NET_MAX_CONTEXTS=10

tests/net/lib/http_server/prototype/prj.conf

@@ -7,7 +7,7 @@ CONFIG_POSIX_API=y
 
 CONFIG_ENTROPY_GENERATOR=y
 CONFIG_TEST_RANDOM_GENERATOR=y
-CONFIG_POSIX_MAX_FDS=10
+CONFIG_ZVFS_OPEN_MAX=10
 CONFIG_REQUIRES_FULL_LIBC=y
 CONFIG_EVENTFD_MAX=10
 CONFIG_NET_MAX_CONTEXTS=10

tests/net/lib/http_server/tls/prj.conf

@@ -37,9 +37,9 @@ CONFIG_NET_BUF_TX_COUNT=128
 CONFIG_NET_BUF_RX_COUNT=128
 CONFIG_NET_PKT_TX_COUNT=16
 CONFIG_NET_PKT_RX_COUNT=16
-CONFIG_POSIX_MAX_FDS=32
+CONFIG_ZVFS_OPEN_MAX=32
 CONFIG_NET_SOCKETS_POLL_MAX=32
-CONFIG_POSIX_MAX_FDS=32
+CONFIG_ZVFS_OPEN_MAX=32
 CONFIG_REQUIRES_FULL_LIBC=y
 CONFIG_EVENTFD_MAX=10
 CONFIG_NET_MAX_CONTEXTS=10

tests/net/pm/prj.conf

@@ -7,7 +7,7 @@ CONFIG_NET_L2_ETHERNET=n
 CONFIG_NET_UDP=y
 CONFIG_NET_IPV4=y
 CONFIG_NET_SOCKETS=y
-CONFIG_POSIX_MAX_FDS=2
+CONFIG_ZVFS_OPEN_MAX=2
 CONFIG_ZTEST_STACK_SIZE=2048
 CONFIG_MAIN_STACK_SIZE=2048
 CONFIG_NET_LOG=y

tests/net/socket/af_packet/prj.conf

@@ -6,7 +6,7 @@ CONFIG_NET_UDP=y
 CONFIG_NET_TCP=n
 CONFIG_NET_SOCKETS=y
 CONFIG_NET_SOCKETS_PACKET=y
-CONFIG_POSIX_MAX_FDS=8
+CONFIG_ZVFS_OPEN_MAX=8
 CONFIG_NET_IPV6_DAD=n
 CONFIG_NET_IPV6_MLD=n
 

tests/net/socket/af_packet_ipproto_raw/prj.conf

@@ -6,7 +6,7 @@ CONFIG_NET_UDP=n
 CONFIG_NET_TCP=n
 CONFIG_NET_SOCKETS=y
 CONFIG_NET_SOCKETS_PACKET=y
-CONFIG_POSIX_MAX_FDS=8
+CONFIG_ZVFS_OPEN_MAX=8
 CONFIG_NET_SOCKETS_LOG_LEVEL_DBG=y
 CONFIG_NET_CORE_LOG_LEVEL_DBG=y
 

tests/net/socket/poll/prj.conf

@@ -5,7 +5,7 @@ CONFIG_NET_IPV6=y
 CONFIG_NET_UDP=y
 CONFIG_NET_TCP=y
 CONFIG_NET_SOCKETS=y
-CONFIG_POSIX_MAX_FDS=10
+CONFIG_ZVFS_OPEN_MAX=10
 CONFIG_NET_PKT_TX_COUNT=8
 CONFIG_NET_PKT_RX_COUNT=8
 CONFIG_NET_MAX_CONN=5

tests/net/socket/reuseaddr_reuseport/prj.conf

@@ -28,7 +28,7 @@ CONFIG_NET_CONTEXT_REUSEPORT=y
 CONFIG_NET_HOSTNAME_ENABLE=y
 CONFIG_NET_HOSTNAME="ztest_hostname"
 
-CONFIG_POSIX_MAX_FDS=8
+CONFIG_ZVFS_OPEN_MAX=8
 CONFIG_NET_MAX_CONN=10
 CONFIG_NET_MAX_CONTEXTS=10
 

tests/net/socket/select/prj.conf

@@ -10,7 +10,7 @@ CONFIG_NET_IPV4=n
 CONFIG_NET_IPV6=y
 CONFIG_NET_SOCKETS=y
 # Defines fd_set size
-CONFIG_POSIX_MAX_FDS=33
+CONFIG_ZVFS_OPEN_MAX=33
 
 # Network driver config
 CONFIG_TEST_RANDOM_GENERATOR=y

tests/net/socket/select/src/main.c

@@ -34,7 +34,7 @@ ZTEST_USER(net_socket_select, test_fd_set)
 {
 	zsock_fd_set set;
 
-	/* Relies on specific value of CONFIG_POSIX_MAX_FDS in prj.conf */
+	/* Relies on specific value of CONFIG_ZVFS_OPEN_MAX in prj.conf */
 	zassert_equal(sizeof(set.bitset), sizeof(uint32_t) * 2, "");
 
 	ZSOCK_FD_ZERO(&set);

tests/net/socket/service/prj.conf

@@ -5,7 +5,7 @@ CONFIG_NET_IPV6=y
 CONFIG_NET_UDP=y
 CONFIG_NET_TCP=y
 CONFIG_NET_SOCKETS=y
-CONFIG_POSIX_MAX_FDS=10
+CONFIG_ZVFS_OPEN_MAX=10
 CONFIG_NET_PKT_TX_COUNT=8
 CONFIG_NET_PKT_RX_COUNT=8
 CONFIG_NET_MAX_CONN=5

tests/net/socket/socketpair/prj.conf

@@ -7,7 +7,7 @@ CONFIG_NET_IPV4=y
 CONFIG_NET_SOCKETS=y
 CONFIG_NET_SOCKETPAIR=y
 CONFIG_NET_SOCKETPAIR_BUFFER_SIZE=64
-CONFIG_POSIX_MAX_FDS=10
+CONFIG_ZVFS_OPEN_MAX=10
 
 # Network driver config
 CONFIG_TEST_RANDOM_GENERATOR=y

tests/net/socket/tcp/prj.conf

@@ -11,7 +11,7 @@ CONFIG_NET_IPV6=y
 CONFIG_NET_IPV6_ND=n
 CONFIG_NET_TCP=y
 CONFIG_NET_SOCKETS=y
-CONFIG_POSIX_MAX_FDS=10
+CONFIG_ZVFS_OPEN_MAX=10
 
 # Network driver config
 CONFIG_NET_DRIVERS=y

tests/net/socket/tcp/src/main.c

@@ -2491,7 +2491,7 @@ static void after(void *arg)
 {
 	ARG_UNUSED(arg);
 
-	for (int i = 0; i < CONFIG_POSIX_MAX_FDS; ++i) {
+	for (int i = 0; i < CONFIG_ZVFS_OPEN_MAX; ++i) {
 		(void)zsock_close(i);
 	}
 }

tests/net/socket/tls/prj.conf

@@ -19,7 +19,7 @@ CONFIG_NET_SOCKETS_TLS_MAX_CONTEXTS=4
 CONFIG_NET_CONTEXT_RCVTIMEO=y
 CONFIG_NET_CONTEXT_SNDTIMEO=y
 CONFIG_NET_CONTEXT_RCVBUF=y
-CONFIG_POSIX_MAX_FDS=20
+CONFIG_ZVFS_OPEN_MAX=20
 
 # Keep timings short for the test
 CONFIG_NET_TCP_TIME_WAIT_DELAY=10

tests/net/socket/tls_ext/prj.conf

@@ -29,7 +29,7 @@ CONFIG_NET_BUF_TX_COUNT=64
 CONFIG_NET_PKT_TX_COUNT=64
 CONFIG_NET_BUF_RX_COUNT=64
 CONFIG_NET_PKT_RX_COUNT=64
-CONFIG_POSIX_MAX_FDS=10
+CONFIG_ZVFS_OPEN_MAX=10
 
 # Stack sizes
 CONFIG_MAIN_STACK_SIZE=2048

tests/net/socket/udp/prj.conf

@@ -7,7 +7,7 @@ CONFIG_NET_IPV4=y
 CONFIG_NET_IPV6=y
 CONFIG_NET_UDP=y
 CONFIG_NET_SOCKETS=y
-CONFIG_POSIX_MAX_FDS=10
+CONFIG_ZVFS_OPEN_MAX=10
 CONFIG_NET_IF_UNICAST_IPV6_ADDR_COUNT=3
 CONFIG_NET_IPV6_DAD=n
 CONFIG_NET_IPV6_MLD=n

tests/net/socket/udp/src/main.c

@@ -2532,7 +2532,7 @@ static void after(void *arg)
 {
 	ARG_UNUSED(arg);
 
-	for (int i = 0; i < CONFIG_POSIX_MAX_FDS; ++i) {
+	for (int i = 0; i < CONFIG_ZVFS_OPEN_MAX; ++i) {
 		(void)zsock_close(i);
 	}
 }

tests/posix/fs/src/test_fs_file.c

@@ -290,7 +290,7 @@ ZTEST(posix_fs_file_test, test_fs_unlink)
 ZTEST(posix_fs_file_test, test_fs_fd_leak)
 {
 	const int reps =
-	    MAX(CONFIG_POSIX_MAX_OPEN_FILES, CONFIG_POSIX_MAX_FDS) + 5;
+	    MAX(CONFIG_POSIX_OPEN_MAX, CONFIG_ZVFS_OPEN_MAX) + 5;
 
 	for (int i = 0; i < reps; i++) {
 		if (i > 0) {