MSYS2-packages/msys2-runtime/0045-Cygwin-signal-Do-not-handle-signal-when-__SIGFLUSHFA.patch

89 lines
3.3 KiB
Diff

From 33799c250f0a7d353cfc34961c7bba26d3a4219a Mon Sep 17 00:00:00 2001
From: Takashi Yano <takashi.yano@nifty.ne.jp>
Date: Mon, 23 Dec 2024 10:33:25 +0900
Subject: [PATCH 45/N] Cygwin: signal: Do not handle signal when
__SIGFLUSHFAST is sent
After the commit d243e51ef1d3, zsh sometimes hangs at startup. This
occurs because SIGCHLD, which should trigger sigsuspend(), is handled
in cygwait() that is used to wait for a wakeup event in sig_send(),
even when __SIGFLUSHFAST is sent. Despite __SIGFLUSHFAST being
required to return before handling the signal, this does not happen.
With this patch, if the signal currently being sent is __SIGFLUSHFAST,
do not handle the received signal and keep it asserted after the
cygwait() for the wakeup event. Apply the same logic to the cygwait()
in the retrying loop for WriteFile() as well.
Applied-from: https://inbox.sourceware.org/cygwin-patches/20241223013332.1269-1-takashi.yano@nifty.ne.jp
Addresses: https://cygwin.com/pipermail/cygwin/2024-December/256954.html
Fixes: d243e51ef1d3 ("Cygwin: signal: Fix deadlock between main thread and sig thread")
Reported-by: Daisuke Fujimura <booleanlabel@gmail.com>
Reviewed-by:
Signed-off-by: Takashi Yano <takashi.yano@nifty.ne.jp>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
winsup/cygwin/release/3.5.6 | 5 +++++
winsup/cygwin/sigproc.cc | 20 +++++++++++++++-----
2 files changed, 20 insertions(+), 5 deletions(-)
create mode 100644 winsup/cygwin/release/3.5.6
diff --git a/winsup/cygwin/release/3.5.6 b/winsup/cygwin/release/3.5.6
new file mode 100644
index 0000000..643d58e
--- /dev/null
+++ b/winsup/cygwin/release/3.5.6
@@ -0,0 +1,5 @@
+Fixes:
+------
+
+- Fix zsh hang at startup.
+ Addresses: https://cygwin.com/pipermail/cygwin/2024-December/256954.html
diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc
index cf43aa9..c298527 100644
--- a/winsup/cygwin/sigproc.cc
+++ b/winsup/cygwin/sigproc.cc
@@ -751,10 +751,14 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls)
res = WriteFile (sendsig, leader, packsize, &nb, NULL);
if (!res || packsize == nb)
break;
- if (cygwait (NULL, 10, cw_sig_eintr) == WAIT_SIGNALED)
+ if (cygwait (NULL, 10, cw_sig_eintr) == WAIT_SIGNALED
+ && pack.si.si_signo != __SIGFLUSHFAST)
_my_tls.call_signal_handler ();
res = 0;
}
+ /* Re-assert signal_arrived which has been cleared in cygwait(). */
+ if (_my_tls.sig)
+ _my_tls.set_signal_arrived ();
if (!res)
{
@@ -785,7 +789,16 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls)
if (wait_for_completion)
{
sigproc_printf ("Waiting for pack.wakeup %p", pack.wakeup);
- rc = cygwait (pack.wakeup, WSSC);
+ do
+ {
+ rc = cygwait (pack.wakeup, WSSC, cw_sig_eintr);
+ if (rc == WAIT_SIGNALED && pack.si.si_signo != __SIGFLUSHFAST)
+ _my_tls.call_signal_handler ();
+ }
+ while (rc != WAIT_OBJECT_0 && rc != WAIT_TIMEOUT);
+ /* Re-assert signal_arrived which has been cleared in cygwait(). */
+ if (_my_tls.sig)
+ _my_tls.set_signal_arrived ();
ForceCloseHandle (pack.wakeup);
}
else
@@ -806,9 +819,6 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls)
rc = -1;
}
- if (wait_for_completion && si.si_signo != __SIGFLUSHFAST)
- _my_tls.call_signal_handler ();
-
out:
if (communing && rc)
{