From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from conuserg-09.nifty.com (conuserg-09.nifty.com [210.131.2.76]) by sourceware.org (Postfix) with ESMTPS id 86B28385800F for ; Thu, 28 Jan 2021 14:12:33 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 86B28385800F Received: from localhost.localdomain (x067108.dynamic.ppp.asahi-net.or.jp [122.249.67.108]) (authenticated) by conuserg-09.nifty.com with ESMTP id 10SEBeIZ020745; Thu, 28 Jan 2021 23:12:08 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-09.nifty.com 10SEBeIZ020745 X-Nifty-SrcIP: [122.249.67.108] From: Takashi Yano To: cygwin-patches@cygwin.com Subject: [PATCH v3 1/2] Cygwin: console: Make read() thread-safe. Date: Thu, 28 Jan 2021 23:11:32 +0900 Message-Id: <20210128141133.734-2-takashi.yano@nifty.ne.jp> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210128141133.734-1-takashi.yano@nifty.ne.jp> References: <20210128141133.734-1-takashi.yano@nifty.ne.jp> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-10.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: cygwin-patches@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Cygwin core component patch submission and discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Jan 2021 14:12:35 -0000 - Currently read() is somehow not thread-safe. This patch fixes the issue. --- winsup/cygwin/fhandler.h | 10 ++++++++++ winsup/cygwin/fhandler_console.cc | 11 ++++++----- winsup/cygwin/fhandler_termios.cc | 2 ++ 3 files changed, 18 insertions(+), 5 deletions(-) diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h index a4c1a3816..2fad7d33c 100644 --- a/winsup/cygwin/fhandler.h +++ b/winsup/cygwin/fhandler.h @@ -1905,6 +1905,8 @@ class fhandler_termios: public fhandler_base tty_min *_tc; tty *get_ttyp () {return (tty *) tc ();} int eat_readahead (int n); + virtual void acquire_input_mutex_if_necessary (DWORD ms) {}; + virtual void release_input_mutex_if_necessary (void) {}; public: tty_min*& tc () {return _tc;} @@ -2212,6 +2214,14 @@ private: void __release_input_mutex (const char *fn, int ln); DWORD __acquire_output_mutex (const char *fn, int ln, DWORD ms); void __release_output_mutex (const char *fn, int ln); + void acquire_input_mutex_if_necessary (DWORD ms) + { + acquire_input_mutex (ms); + } + void release_input_mutex_if_necessary (void) + { + release_input_mutex (); + } char *&rabuf (); size_t &ralen (); diff --git a/winsup/cygwin/fhandler_console.cc b/winsup/cygwin/fhandler_console.cc index 02d0ac052..0b404411e 100644 --- a/winsup/cygwin/fhandler_console.cc +++ b/winsup/cygwin/fhandler_console.cc @@ -571,31 +571,34 @@ wait_retry: #define buf ((char *) pv) int ret; - acquire_attach_mutex (INFINITE); acquire_input_mutex (INFINITE); + acquire_attach_mutex (INFINITE); ret = process_input_message (); - release_input_mutex (); release_attach_mutex (); switch (ret) { case input_error: + release_input_mutex (); goto err; case input_processing: + release_input_mutex (); continue; case input_ok: /* input ready */ break; case input_signalled: /* signalled */ + release_input_mutex (); goto sig_exit; case input_winch: + release_input_mutex (); continue; default: /* Should not come here */ + release_input_mutex (); goto err; } } /* Check console read-ahead buffer filled from terminal requests */ - acquire_input_mutex (INFINITE); while (con.cons_rapoi && *con.cons_rapoi && buflen) { buf[copied_chars++] = *con.cons_rapoi++; @@ -984,9 +987,7 @@ fhandler_console::process_input_message (void) if (toadd) { ssize_t ret; - release_input_mutex (); line_edit_status res = line_edit (toadd, nread, *ti, &ret); - acquire_input_mutex (INFINITE); if (res == line_edit_signalled) { stat = input_signalled; diff --git a/winsup/cygwin/fhandler_termios.cc b/winsup/cygwin/fhandler_termios.cc index 36bc6255f..9fbace95c 100644 --- a/winsup/cygwin/fhandler_termios.cc +++ b/winsup/cygwin/fhandler_termios.cc @@ -332,7 +332,9 @@ fhandler_termios::line_edit (const char *rptr, size_t nread, termios& ti, termios_printf ("got interrupt %d, sending signal %d", c, sig); eat_readahead (-1); + release_input_mutex_if_necessary (); tc ()->kill_pgrp (sig); + acquire_input_mutex_if_necessary (INFINITE); ti.c_lflag &= ~FLUSHO; sawsig = true; goto restart_output; -- 2.30.0