[GHC] #16150: Data races in itimer_thread_func reported by ThreadSanitizer

[GHC]

#16150: Data races in itimer_thread_func reported by ThreadSanitizer
-------------------------------------+-------------------------------------
           Reporter:  gnezdo         |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Runtime        |           Version:  8.4.4
  System                             |
           Keywords:                 |  Operating System:  Linux
       Architecture:  x86_64         |   Type of failure:  Incorrect result
  (amd64)                            |  at runtime
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 Our local environment allows running Haskell programs under
 ThreadSanitizer. Even though the GHC runtime and compiled Haskell code are
 not instrumented, ThreadSanitizer still found a bug through interceptor
 instrumentation. I'll try to minimize the case and create a reproducer,
 but in case somebody wants to look at this with just the report, here it
 is (mildly massaged to remove irrelevant addresses):

 {{{
 ==================
 WARNING: ThreadSanitizer: data race (pid=2367)
   Write of size 1 at 0x55986a3e4f10 by thread T1:
     #0 pthread_mutex_destroy llvm/compiler-
 rt/lib/tsan/rtl/tsan_interceptors.cc:1245:3
     #1 itimer_thread_func
 vendor_src/v8_4_4/rts/posix/itimer/Pthread.c:152:5

   Previous atomic read of size 1 at 0x55986a3e4f10 by main thread:
     #0 pthread_mutex_lock llvm/compiler-
 rt/lib/sanitizer_common/sanitizer_common_interceptors.inc:4097:3
     #1 startTicker vendor_src/v8_4_4/rts/posix/itimer/Pthread.c:184:5
     #2 exitTicker vendor_src/v8_4_4/rts/posix/itimer/Pthread.c:206
     #3 __libc_start_main <null> (libc.so.6+0x38bbc)

   Location is global 'mutex' of size 40 at 0x55986a3e4f10

   Thread T1 'ghc_ticker' (tid=2369, running) created by main thread at:
     #0 pthread_create llvm/compiler-
 rt/lib/tsan/rtl/tsan_interceptors.cc:980:3
     #1 initTicker vendor_src/v8_4_4/rts/posix/itimer/Pthread.c:171:11
     #2 __libc_start_main <null> (libc.so.6+0x38bbc)

 SUMMARY: ThreadSanitizer: data race
 vendor_src/v8_4_4/rts/posix/itimer/Pthread.c:152:5 in itimer_thread_func
 ==================
 ==================
 WARNING: ThreadSanitizer: data race (pid=2367)
   Write of size 8 at 0x55986a3e4ee0 by thread T1:
     #0 pthread_cond_destroy llvm/compiler-
 rt/lib/tsan/rtl/tsan_interceptors.cc:1216:3
     #1 itimer_thread_func
 vendor_src/v8_4_4/rts/posix/itimer/Pthread.c:153:5

   Previous read of size 8 at 0x55986a3e4ee0 by main thread (mutexes: write
 M146179626018688784):
     #0 pthread_cond_signal llvm/compiler-
 rt/lib/tsan/rtl/tsan_interceptors.cc:1202:3
     #1 signalCondition vendor_src/v8_4_4/rts/posix/OSThreads.c:111:11
     #2 __libc_start_main <null> (libc.so.6+0x38bbc)

   Location is global 'start_cond' of size 48 at 0x55986a3e4ee0

   Mutex M146179626018688784 is already destroyed.

   Thread T1 'ghc_ticker' (tid=2369, running) created by main thread at:
     #0 pthread_create llvm/compiler-
 rt/lib/tsan/rtl/tsan_interceptors.cc:980:3
     #1 initTicker vendor_src/v8_4_4/rts/posix/itimer/Pthread.c:171:11
     #2 __libc_start_main <null> (libc.so.6+0x38bbc)

 SUMMARY: ThreadSanitizer: data race
 vendor_src/v8_4_4/rts/posix/itimer/Pthread.c:153:5 in itimer_thread_func
 ==================
 ThreadSanitizer: reported 2 warnings
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16150>
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