From: Takashi Yano <takashi.yano@nifty.ne.jp>
To: cygwin-patches@cygwin.com
Subject: [PATCH] Cygwin: sigproc: Fix potential race issue regarding exit_state.
Date: Sat, 20 Nov 2021 03:39:05 +0900 [thread overview]
Message-ID: <20211119183905.1878-1-takashi.yano@nifty.ne.jp> (raw)
- If sig_send() is called while another thread is processing exit(),
race issue regarding exit_state may occur. This patch fixes the
issue.
---
winsup/cygwin/sigproc.cc | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc
index fde41a9f6..02d875a7f 100644
--- a/winsup/cygwin/sigproc.cc
+++ b/winsup/cygwin/sigproc.cc
@@ -603,11 +603,6 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls)
its_me = false;
}
- /* Do not send signal to myself if exiting, which will be
- ignored in wait_sig thread. */
- if (its_me && exit_state > ES_EXIT_STARTING && si.si_signo > 0)
- goto out;
-
if (its_me)
sendsig = my_sendsig;
else
@@ -1372,7 +1367,7 @@ wait_sig (VOID *)
sigq.retry = false;
/* Don't process signals when we start exiting */
if (exit_state > ES_EXIT_STARTING && pack.si.si_signo > 0)
- continue;
+ goto skip_process_signal;
sigset_t dummy_mask;
threadlist_t *tl_entry;
@@ -1384,8 +1379,10 @@ wait_sig (VOID *)
pack.mask = &dummy_mask;
}
- sigpacket *q = &sigq.start;
- bool clearwait = false;
+ sigpacket *q;
+ q = &sigq.start;
+ bool clearwait;
+ clearwait = false;
switch (pack.si.si_signo)
{
case __SIGCOMMUNE:
@@ -1482,6 +1479,7 @@ wait_sig (VOID *)
}
if (clearwait && !have_execed)
proc_subproc (PROC_CLEARWAIT, 0);
+skip_process_signal:
if (pack.wakeup)
{
sigproc_printf ("signalling pack.wakeup %p", pack.wakeup);
--
2.33.0
next reply other threads:[~2021-11-19 18:39 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-19 18:39 Takashi Yano [this message]
2021-11-22 12:45 ` Corinna Vinschen
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