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From: Roland McGrath <roland@hack.frob.com>
To: "GNU C. Library" <libc-alpha@sourceware.org> 
Subject: [COMMITTED PATCH] NaCl: Fix lll_futex_timed_wait timeout
	calculation.
Message-Id: <20150528223706.D41FC2C3B00@topped-with-meat.com>
Date: Thu, 28 May 2015 15:37:06 -0700 (PDT)
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Arithmetic is hard.  Let's go shopping.


Thanks,
Roland


2015-05-28  Roland McGrath  <roland@hack.frob.com>

	* sysdeps/nacl/lowlevellock-futex.h (lll_futex_timed_wait):
	Add TIMEOUT to current time, don't subtract it.

diff --git a/sysdeps/nacl/lowlevellock-futex.h b/sysdeps/nacl/lowlevellock-futex.h
index 8d888a2..b614ac8 100644
--- a/sysdeps/nacl/lowlevellock-futex.h
+++ b/sysdeps/nacl/lowlevellock-futex.h
@@ -48,12 +48,12 @@
 	&& __glibc_likely ((_err = __nacl_irt_clock.clock_gettime	\
 			    (CLOCK_REALTIME, &_ts)) == 0))		\
       {                                                                 \
-        _ts.tv_sec -= _to->tv_sec;                                      \
-        _ts.tv_nsec -= _to->tv_nsec;                                    \
-        while (_ts.tv_nsec < 0)                                         \
+	_ts.tv_sec += _to->tv_sec;                                      \
+	_ts.tv_nsec += _to->tv_nsec;                                    \
+	while (_ts.tv_nsec >= 1000000000)                               \
 	  {                                                             \
-            _ts.tv_nsec += 1000000000;                                  \
-            --_ts.tv_sec;                                               \
+	    _ts.tv_nsec -= 1000000000;                                  \
+	    ++_ts.tv_sec;                                               \
 	  }                                                             \
 	_to = &_ts;                                                     \
       }                                                                 \