[newlib-cygwin] Cygwin: sigpending: don't report pending signals for other threads

[Corinna Vinschen <corinna@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=bae987be12b12b18a4e7952a25dba2101f5da1d6

commit bae987be12b12b18a4e7952a25dba2101f5da1d6
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Fri Jul 12 17:18:48 2019 +0200

    Cygwin: sigpending: don't report pending signals for other threads
    
    The sigpending mechanism failed to check if the pending signal was a
    process-wide signal, or a signal for the curent thread.  Fix that by
    adding a matching conditional to wait_sig's __SIGPENDING code.
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/release/3.1.0 | 3 +++
 winsup/cygwin/sigproc.cc    | 9 +++++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/winsup/cygwin/release/3.1.0 b/winsup/cygwin/release/3.1.0
index c8fe555..3b73a18 100644
--- a/winsup/cygwin/release/3.1.0
+++ b/winsup/cygwin/release/3.1.0
@@ -37,3 +37,6 @@ Bug Fixes
 
 - Fix a timerfd deadlock.
   Addresses: https://cygwin.com/ml/cygwin/2019-06/msg00096.html
+
+- Fix sigpending() incorrectly returning signals for unrelated threads.
+  Addresses: https://cygwin.com/ml/cygwin/2019-07/msg00051.html
diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc
index cba1af7..900facd 100644
--- a/winsup/cygwin/sigproc.cc
+++ b/winsup/cygwin/sigproc.cc
@@ -1335,8 +1335,13 @@ wait_sig (VOID *)
 	    *pack.mask = 0;
 	    tl_entry = cygheap->find_tls (pack.sigtls);
 	    while ((q = q->next))
-	      if (pack.sigtls->sigmask & (bit = SIGTOMASK (q->si.si_signo)))
-		*pack.mask |= bit;
+	      {
+		/* Skip thread-specific signals for other threads. */
+		if (q->sigtls && pack.sigtls != q->sigtls)
+		  continue;
+		if (pack.sigtls->sigmask & (bit = SIGTOMASK (q->si.si_signo)))
+		  *pack.mask |= bit;
+	      }
 	    cygheap->unlock_tls (tl_entry);
 	  }
 	  break;