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https://github.com/lwip-tcpip/lwip.git
synced 2024-07-16 09:47:31 +00:00
LWIP_NETCONN_FULLDUPLEX: prevent taking recursive sys arch lock
Calling SYS_ARCH_PROTECT() could happen twice in 'free_socket()' if that free was executed delayed (e.g. in 'done_socket_locked()'). Signed-off-by: goldsimon <goldsimon@gmx.de>
This commit is contained in:
goldsimon
parent
b1fe8cf4b8
commit
1090e9cdec
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@ -297,7 +297,8 @@ static void lwip_setsockopt_callback(void *arg);
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#endif
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static int lwip_getsockopt_impl(int s, int level, int optname, void *optval, socklen_t *optlen);
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static int lwip_setsockopt_impl(int s, int level, int optname, const void *optval, socklen_t optlen);
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static void free_socket(struct lwip_sock *sock, int is_tcp);
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static int free_socket_locked(struct lwip_sock *sock, int is_tcp, union lwip_sock_lastdata *lastdata);
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static void free_socket_free_elements(int is_tcp, union lwip_sock_lastdata *lastdata);
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#if LWIP_IPV4 && LWIP_IPV6
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static void
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@ -329,27 +330,41 @@ lwip_socket_thread_cleanup(void)
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#if LWIP_NETCONN_FULLDUPLEX
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/* Thread-safe increment of sock->fd_used, with overflow check */
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static void
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static int
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sock_inc_used(struct lwip_sock *sock)
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{
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int ret;
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SYS_ARCH_DECL_PROTECT(lev);
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LWIP_ASSERT("sock != NULL", sock != NULL);
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SYS_ARCH_PROTECT(lev);
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++sock->fd_used;
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LWIP_ASSERT("sock->fd_used != 0", sock->fd_used != 0);
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if (sock->fd_free_pending) {
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/* prevent new usage of this socket if free is pending */
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ret = 0;
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} else {
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++sock->fd_used;
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ret = 1;
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LWIP_ASSERT("sock->fd_used != 0", sock->fd_used != 0);
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}
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SYS_ARCH_UNPROTECT(lev);
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return ret;
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}
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/* Like sock_inc_used(), but called under SYS_ARCH_PROTECT lock. */
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static void
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static int
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sock_inc_used_locked(struct lwip_sock *sock)
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{
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LWIP_ASSERT("sock != NULL", sock != NULL);
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if (sock->fd_free_pending) {
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LWIP_ASSERT("sock->fd_used != 0", sock->fd_used != 0);
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return 0;
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}
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++sock->fd_used;
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LWIP_ASSERT("sock->fd_used != 0", sock->fd_used != 0);
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return 1;
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}
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/* In full-duplex mode,sock->fd_used != 0 prevents a socket descriptor from being
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@ -358,33 +373,35 @@ sock_inc_used_locked(struct lwip_sock *sock)
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* This function is called at the end of functions using (try)get_socket*().
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*/
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static void
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done_socket_locked(struct lwip_sock *sock)
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done_socket(struct lwip_sock *sock)
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{
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SYS_ARCH_DECL_PROTECT(lev);
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int freed = 0;
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int is_tcp = 0;
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union lwip_sock_lastdata lastdata;
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LWIP_ASSERT("sock != NULL", sock != NULL);
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SYS_ARCH_PROTECT(lev);
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LWIP_ASSERT("sock->fd_used > 0", sock->fd_used > 0);
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if (--sock->fd_used == 0) {
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if (sock->fd_free_pending) {
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/* free the socket */
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sock->fd_used = 1;
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free_socket(sock, sock->fd_free_pending & LWIP_SOCK_FD_FREE_TCP);
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is_tcp = sock->fd_free_pending & LWIP_SOCK_FD_FREE_TCP;
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freed = free_socket_locked(sock, is_tcp, &lastdata);
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}
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}
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SYS_ARCH_UNPROTECT(lev);
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if (freed) {
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free_socket_free_elements(is_tcp, &lastdata);
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}
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}
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static void
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done_socket(struct lwip_sock *sock)
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{
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SYS_ARCH_DECL_PROTECT(lev);
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SYS_ARCH_PROTECT(lev);
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done_socket_locked(sock);
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SYS_ARCH_UNPROTECT(lev);
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}
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#else /* LWIP_NETCONN_FULLDUPLEX */
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#define sock_inc_used(sock)
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#define sock_inc_used_locked(sock)
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#define sock_inc_used(sock) 1
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#define sock_inc_used_locked(sock) 1
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#define done_socket(sock)
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#define done_socket_locked(sock)
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#endif /* LWIP_NETCONN_FULLDUPLEX */
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/* Translate a socket 'int' into a pointer (only fails if the index is invalid) */
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@ -411,7 +428,9 @@ tryget_socket_unconn(int fd)
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{
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struct lwip_sock *ret = tryget_socket_unconn_nouse(fd);
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if (ret != NULL) {
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sock_inc_used(ret);
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if (!sock_inc_used(ret)) {
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return NULL;
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}
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}
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return ret;
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}
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@ -422,7 +441,9 @@ tryget_socket_unconn_locked(int fd)
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{
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struct lwip_sock *ret = tryget_socket_unconn_nouse(fd);
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if (ret != NULL) {
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sock_inc_used_locked(ret);
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if (!sock_inc_used_locked(ret)) {
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return NULL;
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}
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}
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return ret;
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}
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@ -514,6 +535,44 @@ alloc_socket(struct netconn *newconn, int accepted)
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return -1;
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}
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/** Free a socket (under lock)
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*
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* @param sock the socket to free
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* @param is_tcp != 0 for TCP sockets, used to free lastdata
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* @param lastdata lastdata is stored here, must be freed externally
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*/
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static int
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free_socket_locked(struct lwip_sock *sock, int is_tcp, union lwip_sock_lastdata *lastdata)
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{
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#if LWIP_NETCONN_FULLDUPLEX
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LWIP_ASSERT("sock->fd_used > 0", sock->fd_used > 0);
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sock->fd_used--;
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if (sock->fd_used > 0) {
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sock->fd_free_pending = LWIP_SOCK_FD_FREE_FREE | (is_tcp ? LWIP_SOCK_FD_FREE_TCP : 0);
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return 0;
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}
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#endif
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*lastdata = sock->lastdata;
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sock->lastdata.pbuf = NULL;
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sock->conn = NULL;
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return 1;
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}
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/** Free a socket's leftover members.
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*/
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static void
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free_socket_free_elements(int is_tcp, union lwip_sock_lastdata *lastdata)
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{
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if (lastdata->pbuf != NULL) {
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if (is_tcp) {
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pbuf_free(lastdata->pbuf);
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} else {
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netbuf_delete(lastdata->netbuf);
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}
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}
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}
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/** Free a socket. The socket's netconn must have been
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* delete before!
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*
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@ -523,34 +582,19 @@ alloc_socket(struct netconn *newconn, int accepted)
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static void
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free_socket(struct lwip_sock *sock, int is_tcp)
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{
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int freed;
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union lwip_sock_lastdata lastdata;
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SYS_ARCH_DECL_PROTECT(lev);
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/* Protect socket array */
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SYS_ARCH_PROTECT(lev);
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#if LWIP_NETCONN_FULLDUPLEX
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LWIP_ASSERT("sock->fd_used > 0", sock->fd_used > 0);
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sock->fd_used--;
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if (sock->fd_used > 0) {
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sock->fd_free_pending = LWIP_SOCK_FD_FREE_FREE | (is_tcp ? LWIP_SOCK_FD_FREE_TCP : 0);
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SYS_ARCH_UNPROTECT(lev);
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return;
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}
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#endif
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lastdata = sock->lastdata;
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sock->lastdata.pbuf = NULL;
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sock->conn = NULL;
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freed = free_socket_locked(sock, is_tcp, &lastdata);
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SYS_ARCH_UNPROTECT(lev);
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/* don't use 'sock' after this line, as another task might have allocated it */
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if (lastdata.pbuf != NULL) {
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if (is_tcp) {
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pbuf_free(lastdata.pbuf);
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} else {
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netbuf_delete(lastdata.netbuf);
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}
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if (freed) {
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free_socket_free_elements(is_tcp, &lastdata);
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}
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}
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@ -1993,14 +2037,15 @@ lwip_select(int maxfdp1, fd_set *readset, fd_set *writeset, fd_set *exceptset,
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if (sock->select_waiting == 0) {
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/* overflow - too many threads waiting */
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sock->select_waiting--;
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done_socket_locked(sock);
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nready = -1;
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maxfdp2 = i;
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SYS_ARCH_UNPROTECT(lev);
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done_socket(sock);
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set_errno(EBUSY);
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break;
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}
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done_socket_locked(sock);
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SYS_ARCH_UNPROTECT(lev);
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done_socket(sock);
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} else {
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/* Not a valid socket */
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nready = -1;
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@ -2009,7 +2054,6 @@ lwip_select(int maxfdp1, fd_set *readset, fd_set *writeset, fd_set *exceptset,
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set_errno(EBADF);
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break;
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}
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SYS_ARCH_UNPROTECT(lev);
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}
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}
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@ -2053,13 +2097,14 @@ lwip_select(int maxfdp1, fd_set *readset, fd_set *writeset, fd_set *exceptset,
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if (sock->select_waiting > 0) {
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sock->select_waiting--;
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}
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done_socket_locked(sock);
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SYS_ARCH_UNPROTECT(lev);
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done_socket(sock);
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} else {
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SYS_ARCH_UNPROTECT(lev);
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/* Not a valid socket */
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nready = -1;
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set_errno(EBADF);
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}
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SYS_ARCH_UNPROTECT(lev);
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}
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}
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@ -2165,9 +2210,9 @@ lwip_pollscan(struct pollfd *fds, nfds_t nfds, enum lwip_pollscan_opts opts)
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if (sock->select_waiting == 0) {
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/* overflow - too many threads waiting */
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sock->select_waiting--;
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done_socket_locked(sock);
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nready = -1;
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SYS_ARCH_UNPROTECT(lev);
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done_socket(sock);
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break;
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}
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} else if ((opts & LWIP_POLLSCAN_DEC_WAIT) != 0) {
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@ -2177,9 +2222,8 @@ lwip_pollscan(struct pollfd *fds, nfds_t nfds, enum lwip_pollscan_opts opts)
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sock->select_waiting--;
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}
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}
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done_socket_locked(sock);
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SYS_ARCH_UNPROTECT(lev);
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done_socket(sock);
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/* ... then examine it: */
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/* See if netconn of this socket is ready for read */
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