commit baf20fc9122740ff2baa34d28001e8bdfac9568c
author Josh Gao <jmgao@google.com> Mon Oct 08 17:28:07 2018 -0700
committer Josh Gao <jmgao@google.com> Tue Oct 09 16:27:22 2018 -0700
tree 8e6f717de9cef90828010497ef80ab454c0eb4c6
parent 773c697f815d43182adf1eb430f4899255088d6b

Block TIMER_SIGNAL in sigprocmask(SIG_SETMASK, ...).

Previously, we were zeroing out the reserved signals, when we actually
wanted to have TIMER_SIGNAL always be blocked, and the other signals
always be unblocked. This resulted in process termination when a
SIGEV_THREAD timer callback calls sigprocmask(SIG_SETMASK, ...) with
any signal mask value, and then subsequently fails to complete its
callback and reach the sigtimedwait in bionic before the next timer
iteration triggers.

Add a how argument to filter_reserved_signals to appropriately
block/unblock our reserved signals.

Bug: http://b/116783733
Test: bionic-unit-tests32/64
Change-Id: Ie5339682cdeb914711cd4089cd26ee395704d0df

libc/bionic/poll.cpp

diff --git a/libc/bionic/poll.cpp b/libc/bionic/poll.cpp
index 3df8b18..41b2657 100644
--- a/libc/bionic/poll.cpp
+++ b/libc/bionic/poll.cpp
@@ -71,7 +71,7 @@
   sigset64_t mutable_ss;
   sigset64_t* mutable_ss_ptr = nullptr;
   if (ss != nullptr) {
-    mutable_ss = filter_reserved_signals(*ss);
+    mutable_ss = filter_reserved_signals(*ss, SIG_SETMASK);
     mutable_ss_ptr = &mutable_ss;
   }
 
@@ -121,7 +121,7 @@
   sigset64_t mutable_ss;
   sigset64_t* mutable_ss_ptr = nullptr;
   if (ss != nullptr) {
-    mutable_ss = filter_reserved_signals(*ss);
+    mutable_ss = filter_reserved_signals(*ss, SIG_SETMASK);
     mutable_ss_ptr = &mutable_ss;
   }