Eric Pouech : server/console: Ensure conhost has created the TTY input stream before waiting.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 751a3325a6ac93d11f08088c40b45a9ae05b52de
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=751a3325a6ac93d11f08088c4...

Author: Eric Pouech 
Date:   Fri Dec 17 17:18:51 2021 +0100

server/console: Ensure conhost has created the TTY input stream before waiting.

Some PE executables (like mingw's gdb port) just do something like:
- WaitForSingleObject(GetStdHandle(STD_INPUT_HANDLE), INFINITE) and hang
  for ever (the read operations are done *after* the wait operation
  succeeds)
(of course, the real wait operation is more complex, but the problematic
part boils down to that)

This hangs for ever because conhost's main input thread hasn't been started
yet.

Signed-off-by: Eric Pouech 
Signed-off-by: Jacek Caban 
Signed-off-by: Alexandre Julliard

---

server/console.c | 46 +++++++++++++++++++++++++++++++++-------------
 1 file changed, 33 insertions(+), 13 deletions(-)

diff --git a/server/console.c b/server/console.c
index 977c428cf9f..136c14862e3 100644
--- a/server/console.c
+++ b/server/console.c
@@ -71,13 +71,14 @@ static struct object *console_lookup_name( struct object *obj, struct unicode_st
                                            unsigned int attr, struct object *root );
 static struct object *console_open_file( struct object *obj, unsigned int access,
                                          unsigned int sharing, unsigned int options );
+static int console_add_queue( struct object *obj, struct wait_queue_entry *entry );

static const struct object_ops console_ops =
 {
     sizeof(struct console),           /* size */
     &file_type,                       /* type */
     console_dump,                     /* dump */
-    add_queue,                        /* add_queue */
+    console_add_queue,                /* add_queue */
     remove_queue,                     /* remove_queue */
     console_signaled,                 /* signaled */
     no_satisfied,                     /* satisfied */
@@ -129,14 +130,15 @@ struct console_host_ioctl

struct console_server
 {
-    struct object         obj;         /* object header */
-    struct fd            *fd;          /* pseudo-fd for ioctls */
-    struct console       *console;     /* attached console */
-    struct list           queue;       /* ioctl queue */
-    struct list           read_queue;  /* blocking read queue */
-    int                   busy;        /* flag if server processing an ioctl */
-    int                   term_fd;     /* UNIX terminal fd */
-    struct termios        termios;     /* original termios */
+    struct object         obj;            /* object header */
+    struct fd            *fd;             /* pseudo-fd for ioctls */
+    struct console       *console;        /* attached console */
+    struct list           queue;          /* ioctl queue */
+    struct list           read_queue;     /* blocking read queue */
+    unsigned int          busy : 1;       /* flag if server processing an ioctl */
+    unsigned int          once_input : 1; /* flag if input thread has already been requested */
+    int                   term_fd;        /* UNIX terminal fd */
+    struct termios        termios;        /* original termios */
 };

static void console_server_dump( struct object *obj, int verbose );
@@ -462,6 +464,23 @@ static const struct fd_ops console_connection_fd_ops =

static struct list screen_buffer_list = LIST_INIT(screen_buffer_list);

+static int queue_host_ioctl( struct console_server *server, unsigned int code, unsigned int output,
+                             struct async *async, struct async_queue *queue );
+
+static int console_add_queue( struct object *obj, struct wait_queue_entry *entry )
+{
+    struct console *console = (struct console*)obj;
+    assert( obj->ops == &console_ops );
+    /* before waiting, ensure conhost's input thread has been started */
+    if (console->server && !console->server->once_input)
+    {
+        console->server->once_input = 1;
+        if (console->server->term_fd == -1)
+            queue_host_ioctl( console->server, IOCTL_CONDRV_PEEK, 0, NULL, NULL );
+    }
+    return add_queue( &console->obj, entry );
+}
+
 static int console_signaled( struct object *obj, struct wait_queue_entry *entry )
 {
     struct console *console = (struct console*)obj;
@@ -889,9 +908,10 @@ static struct object *create_console_server( void )
     struct console_server *server;

if (!(server = alloc_object( &console_server_ops ))) return NULL;
-    server->console = NULL;
-    server->busy    = 0;
-    server->term_fd = -1;
+    server->console    = NULL;
+    server->busy       = 0;
+    server->once_input = 0;
+    server->term_fd    = -1;
     list_init( &server->queue );
     list_init( &server->read_queue );
     server->fd = alloc_pseudo_fd( &console_server_fd_ops, &server->obj, FILE_SYNCHRONOUS_IO_NONALERT );
@@ -1315,7 +1335,7 @@ static int console_input_add_queue( struct object *obj, struct wait_queue_entry
         set_error( STATUS_ACCESS_DENIED );
         return 0;
     }
-    return add_queue( &current->process->console->obj, entry );
+    return console_add_queue( &current->process->console->obj, entry );
 }

static struct fd *console_input_get_fd( struct object *obj )