https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=09a54135cecacc2fcdc844fcf12a73c8191439e0
commit 09a54135cecacc2fcdc844fcf12a73c8191439e0 Author: Takashi Yano <[email protected]> Date: Fri Mar 4 22:02:35 2022 +0900 Cygwin: pty: Fix a possible race issue in initialization of pcon. - Currently, tty::pcon_start flag is cleared before transfer_input() in master::write(), however, the code in setup_pseudoconsole() waits for transfer_input() using tty::pcon_start. This possibly causes the race issue. The patch fixes this potential issue. Diff: --- winsup/cygwin/fhandler_tty.cc | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc index 2d7e2cf69..a97460660 100644 --- a/winsup/cygwin/fhandler_tty.cc +++ b/winsup/cygwin/fhandler_tty.cc @@ -3297,7 +3297,8 @@ fhandler_pty_slave::setup_pseudoconsole (bool nopcon) get_ttyp ()->pcon_start_pid = myself->pid; WriteFile (get_output_handle (), "\033[6n", 4, &n, NULL); ReleaseMutex (input_mutex); - while (get_ttyp ()->pcon_start) + while (get_ttyp ()->pcon_start_pid) + /* wait for completion of transfer_input() in master::write(). */ Sleep (1); } /* Attach to the pseudo console which already exits. */
