libs/newlib-cygwin
libs/newlib-cygwin
4
0
Fork 0
mirror of git://sourceware.org/git/newlib-cygwin.git synced 2025-02-21 00:07:36 +08:00
Code Issues Projects Releases Wiki Activity

Cygwin: pty: Additional race issue fix regarding pseudo console.

Browse Source 
- In commit bb93c6d7, the race issue was not completely fixed. In
  the pseudo console inheritance, if the destination process to
  which the ownership of pseudo console switches, is found but exits
  before switching, the inheritance fails. Currently, this extremely
  rarely happens. This patch fixes the issue.
This commit is contained in:
Takashi Yano 2021-04-21 12:06:00 +09:00 committed by Corinna Vinschen
parent 13fd26ecf5
commit 01387f1ff4
1 changed files with 14 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
winsup/cygwin/fhandler_tty.cc
View File

@ -64,6 +64,8 @@ struct pipe_reply {
extern HANDLE attach_mutex; /* Defined in fhandler_console.cc */
inline static bool pcon_pid_alive (DWORD pid);
DWORD
fhandler_pty_common::get_console_process_id (DWORD pid, bool match,
bool cygwin, bool stub_only)
@ -90,20 +92,18 @@ fhandler_pty_common::get_console_process_id (DWORD pid, bool match,
else
{
pinfo p (cygwin_pid (list[i]));
if (!!p && p->dwProcessId && p->exec_dwProcessId
&& p->dwProcessId != p->exec_dwProcessId)
if (!!p && p->exec_dwProcessId)
{
res_pri = list[i];
res_pri = stub_only ? p->exec_dwProcessId : list[i];
break;
}
if (!!p && !res)
if (!p && !res && pcon_pid_alive (list[i]) && stub_only)
res = list[i];
if (!!p && !res && !stub_only)
res = list[i];
}
}
if (stub_only)
return res_pri;
else
return res_pri ?: res;
return res_pri ?: res;
}
static bool isHybrid;
@ -3384,35 +3384,17 @@ fallback:
void
fhandler_pty_slave::close_pseudoconsole (tty *ttyp, DWORD force_switch_to)
{
DWORD switch_to_stub = 0, switch_to = 0;
DWORD new_pcon_pid = 0;
DWORD switch_to = 0;
if (force_switch_to)
{
switch_to_stub = force_switch_to;
new_pcon_pid = force_switch_to;
switch_to = force_switch_to;
ttyp->setpgid (force_switch_to + MAX_PID);
}
else if (pcon_pid_self (ttyp->pcon_pid))
{
/* Search another process which attaches to the pseudo console */
DWORD current_pid = myself->exec_dwProcessId ?: myself->dwProcessId;
switch_to = get_console_process_id (current_pid, false, true);
if (switch_to)
{
pinfo p (cygwin_pid (switch_to));
if (p)
{
if (p->exec_dwProcessId)
switch_to_stub = p->exec_dwProcessId;
new_pcon_pid = p->exec_dwProcessId;
}
}
else
{
switch_to = get_console_process_id (current_pid, false, false);
if (switch_to)
new_pcon_pid = switch_to;
}
switch_to = get_console_process_id (current_pid, false, true, true);
}
if (ttyp->pcon_activated)
{
@ -3420,7 +3402,6 @@ fhandler_pty_slave::close_pseudoconsole (tty *ttyp, DWORD force_switch_to)
ttyp->previous_output_code_page = GetConsoleOutputCP ();
if (pcon_pid_self (ttyp->pcon_pid))
{
switch_to = switch_to_stub ?: switch_to;
if (switch_to)
{
/* Change pseudo console owner to another process */
@ -3454,7 +3435,7 @@ fhandler_pty_slave::close_pseudoconsole (tty *ttyp, DWORD force_switch_to)
CloseHandle (ttyp->h_pcon_conhost_process);
CloseHandle (ttyp->h_pcon_in);
CloseHandle (ttyp->h_pcon_out);
ttyp->pcon_pid = new_pcon_pid;
ttyp->pcon_pid = switch_to;
ttyp->h_pcon_write_pipe = new_write_pipe;
ttyp->h_pcon_condrv_reference = new_condrv_reference;
ttyp->h_pcon_conhost_process = new_conhost_process;
@ -3513,8 +3494,8 @@ fhandler_pty_slave::close_pseudoconsole (tty *ttyp, DWORD force_switch_to)
}
else if (pcon_pid_self (ttyp->pcon_pid))
{
if (switch_to_stub)
ttyp->pcon_pid = new_pcon_pid;
if (switch_to)
ttyp->pcon_pid = switch_to;
else
{
ttyp->pcon_pid = 0;