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* dtable.cc (dtable::find_fifo): Release lock after fifo found (still racy).

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* fhandler.h (fhandler_fifo::get_io_handle): New fifo-specific method.
* fhandler_fifo.cc (fhandler_fifo::close): Close output_handle only if it is
open.
(fhandler_fifo::open_not_mine): Reorganize slightly.  Don't call _pinfo methods
when the fifo is owned by me or suffer dtable lock_cs deadlock.
(fhandler_fifo::open): Call open_not_mine first, otherwise open myself
(racy).
* pinfo.cc (_pinfo::commune_recv): Duplicate fifo handles here in requesting
processes arena to avoid one potential race (of many).
(_pinfo::commune_send): Move all PICOM_FIFO code under one case statement.
* thread.cc (pthread::init_mainthread) Use existing hMainProc handle rather
than calling GetCurrentProcess.
This commit is contained in:
Christopher Faylor
2004-06-07 04:26:32 +00:00
parent 6a02213b52
commit beffbc5efd
6 changed files with 119 additions and 71 deletions
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107
winsup/cygwin/fhandler_fifo.cc
View File

@@ -60,7 +60,8 @@ int
fhandler_fifo::close ()
{
fhandler_pipe::close ();
CloseHandle (get_output_handle ());
if (get_output_handle ())
CloseHandle (get_output_handle ());
set_use (-1);
return 0;
}
@@ -72,44 +73,53 @@ fhandler_fifo::open_not_mine (int flags)
winpids pids;
static int flagtypes[] = {DUMMY_O_RDONLY | O_RDWR, O_WRONLY | O_APPEND | O_RDWR};
HANDLE *usehandles[2] = {&(get_handle ()), &(get_output_handle ())};
int res;
int res = 0;
int testflags = (flags & (O_RDWR | O_WRONLY | O_APPEND)) ?: DUMMY_O_RDONLY;
for (unsigned i = 0; i < pids.npids; i++)
{
_pinfo *p = pids[i];
HANDLE hp = OpenProcess (PROCESS_DUP_HANDLE, false, p->dwProcessId);
if (!hp)
{
__seterrno ();
goto err;
}
HANDLE handles[2];
commune_result r;
r = p->commune_send (PICOM_FIFO, get_win32_name ());
if (r.handles[0] == NULL)
continue; // process doesn't own fifo
flags = (flags & (O_RDWR | O_WRONLY | O_APPEND)) ?: DUMMY_O_RDONLY;
for (int i = 0; i < 2; i++)
if (p->pid != myself->pid)
{
if (!(flags & flagtypes[i]))
r = p->commune_send (PICOM_FIFO, get_win32_name ());
if (r.handles[0] == NULL)
continue; // process doesn't own fifo
}
else
{
/* FIXME: racy? */
fhandler_fifo *fh = cygheap->fdtab.find_fifo (get_win32_name ());
if (!fh)
continue;
if (!DuplicateHandle (hp, r.handles[i], hMainProc, usehandles[i], 0,
false, DUPLICATE_SAME_ACCESS))
if (!DuplicateHandle (hMainProc, fh->get_handle (), hMainProc,
&r.handles[0], 0, false, DUPLICATE_SAME_ACCESS))
{
debug_printf ("couldn't duplicate handle %d/%p, %E", i, handles[i]);
__seterrno ();
goto err;
goto out;
}
if (i == 0)
if (!DuplicateHandle (hMainProc, fh->get_handle (), hMainProc,
&r.handles[1], 0, false, DUPLICATE_SAME_ACCESS))
{
read_state = CreateEvent (&sec_none_nih, FALSE, FALSE, NULL);
need_fork_fixup (true);
CloseHandle (r.handles[0]);
__seterrno ();
goto out;
}
}
CloseHandle (hp);
for (int i = 0; i < 2; i++)
if (!(testflags & flagtypes[i]))
CloseHandle (r.handles[i]);
else
{
*usehandles[i] = r.handles[i];
if (i == 0)
{
read_state = CreateEvent (&sec_none_nih, FALSE, FALSE, NULL);
need_fork_fixup (true);
}
}
res = 1;
set_flags (flags);
@@ -118,10 +128,6 @@ fhandler_fifo::open_not_mine (int flags)
set_errno (EAGAIN);
err:
res = 0;
debug_printf ("failed");
out:
debug_printf ("res %d", res);
return res;
@@ -132,26 +138,31 @@ fhandler_fifo::open (int flags, mode_t)
{
int res = 1;
set_io_handle (NULL);
set_output_handle (NULL);
if (open_not_mine (flags))
goto out;
fhandler_pipe *fhs[2];
if (create (fhs, 0, flags, true))
goto errnout;
set_flags (fhs[0]->get_flags ());
set_io_handle (fhs[0]->get_handle ());
set_output_handle (fhs[1]->get_handle ());
guard = fhs[0]->guard;
read_state = fhs[0]->read_state;
writepipe_exists = fhs[1]->writepipe_exists;
orig_pid = fhs[0]->orig_pid;
id = fhs[0]->id;
delete (fhs[0]);
delete (fhs[1]);
set_use (1);
goto out;
errnout:
__seterrno ();
res = 0;
{
__seterrno ();
res = 0;
}
else
{
set_flags (fhs[0]->get_flags ());
set_io_handle (fhs[0]->get_handle ());
set_output_handle (fhs[1]->get_handle ());
guard = fhs[0]->guard;
read_state = fhs[0]->read_state;
writepipe_exists = fhs[1]->writepipe_exists;
orig_pid = fhs[0]->orig_pid;
id = fhs[0]->id;
delete (fhs[0]);
delete (fhs[1]);
set_use (1);
}
out:
debug_printf ("returning %d, errno %d", res, get_errno ());