https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66756
Bug ID: 66756
Summary: libgfortran: ThreadSanitizer: lock-order-inversion
Product: gcc
Version: 5.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libfortran
Assignee: unassigned at gcc dot gnu.org
Reporter: Joost.VandeVondele at mat dot ethz.ch
Target Milestone: ---
After building libgfortran with -fsanitize=thread (see below) any Fortran
program that opens a file fails with:
> cat test.f90
OPEN(10,FILE="foo.bar")
CLOSE(10)
END
> gfortran -fsanitize=thread -g test.f90
> ./a.out
WARNING: ThreadSanitizer: lock-order-inversion (potential deadlock) (pid=28274)
Cycle in lock order graph: M20 (0x7f4472668d80) => M21 (0x7d580000f3d0) =>
M20
Mutex M21 acquired here while holding mutex M20 in main thread:
#0 pthread_mutex_lock
/data/vjoost/toolchain-sanitize/build/gcc-5.1.0/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:2988
(libtsan.so.0+0x0000000349a6)
#1 __gthread_mutex_lock ../libgcc/gthr-default.h:748
(libgfortran.so.3+0x000000160c4b)
#2 insert_unit
/data/vjoost/toolchain-sanitize/build/gcc-5.1.0/libgfortran/io/unit.c:220
(libgfortran.so.3+0x000000160c4b)
#3 get_external_unit
/data/vjoost/toolchain-sanitize/build/gcc-5.1.0/libgfortran/io/unit.c:330
(libgfortran.so.3+0x000000160dc5)
#4 _gfortrani_find_or_create_unit
/data/vjoost/toolchain-sanitize/build/gcc-5.1.0/libgfortran/io/unit.c:394
(libgfortran.so.3+0x000000160ff8)
#5 _gfortran_st_open
/data/vjoost/toolchain-sanitize/build/gcc-5.1.0/libgfortran/io/open.c:829
(libgfortran.so.3+0x000000154f47)
#6 MAIN__ /data/vjoost/gnu/bugs/test.f90:1 (a.out+0x000000400a67)
#7 main /data/vjoost/gnu/bugs/test.f90:4 (a.out+0x000000400b30)
Hint: use TSAN_OPTIONS=second_deadlock_stack=1 to get more informative
warning message
Mutex M20 acquired here while holding mutex M21 in main thread:
#0 pthread_mutex_lock
/data/vjoost/toolchain-sanitize/build/gcc-5.1.0/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:2988
(libtsan.so.0+0x0000000349a6)
#1 __gthread_mutex_lock ../libgcc/gthr-default.h:748
(libgfortran.so.3+0x0000001644e6)
#2 _gfortrani_find_file
/data/vjoost/toolchain-sanitize/build/gcc-5.1.0/libgfortran/io/unix.c:1613
(libgfortran.so.3+0x0000001644e6)
#3 _gfortrani_new_unit
/data/vjoost/toolchain-sanitize/build/gcc-5.1.0/libgfortran/io/open.c:486
(libgfortran.so.3+0x00000015427f)
#4 already_open
/data/vjoost/toolchain-sanitize/build/gcc-5.1.0/libgfortran/io/open.c:672
(libgfortran.so.3+0x00000015502e)
#5 _gfortran_st_open
/data/vjoost/toolchain-sanitize/build/gcc-5.1.0/libgfortran/io/open.c:837
(libgfortran.so.3+0x00000015502e)
#6 MAIN__ /data/vjoost/gnu/bugs/test.f90:1 (a.out+0x000000400a67)
#7 main /data/vjoost/gnu/bugs/test.f90:4 (a.out+0x000000400b30)
SUMMARY: ThreadSanitizer: lock-order-inversion (potential deadlock)
../libgcc/gthr-default.h:748 __gthread_mutex_lock
To build the sanitized libgfortran one first builds gcc, followed by the
equivalent of:
cd
/data/vjoost/toolchain-sanitize/build/gcc-5.1.0/obj/x86_64-unknown-linux-gnu/libgfortran
make clean
make CFLAGS="-std=gnu99 -g -O2 -fsanitize=thread " FCFLAGS="-g -O2
-fsanitize=thread" CXXFLAGS="-std=gnu99 -g -O2 -fsanitize=thread "
LDFLAGS="-B`pwd`/../libsanitizer/tsan/.libs/
-Wl,-rpath,`pwd`/../libsanitizer/tsan/.libs/ -fsanitize=thread"
make install
