Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

join() hang #11

Closed
nyh opened this issue Jun 24, 2013 · 1 comment
Closed

join() hang #11

nyh opened this issue Jun 24, 2013 · 1 comment
Assignees
Labels

Comments

@nyh
Copy link
Contributor

nyh commented Jun 24, 2013

In one run of tst-mutex, the test hung at the end when joining the 20 test threads.

Looking at "osv info threads", we see
36 (0xffffc0003383e000) cpu1 terminating ?? at arch/x64/entry.S:101 vruntime 1372016020739989192
37 (0xffffc00033829000) cpu1 terminated ?? at arch/x64/entry.S:101 vruntime 1372016020739953420
38 (0xffffc00033813000) cpu1 terminated ?? at arch/x64/entry.S:101 vruntime 1372016022969736399
39 (0xffffc000337fe000) cpu1 terminated ?? at arch/x64/entry.S:101 vruntime 1372016024256845711
40 (0xffffc000337e9000) cpu1 terminated ?? at arch/x64/entry.S:101 vruntime 1372016023734879695
41 (0xffffc000337d3000) cpu1 terminated ?? at arch/x64/entry.S:101 vruntime 1372016024605295666
42 (0xffffc000337be000) cpu2 terminated ?? at arch/x64/entry.S:101 vruntime 1372016023144445721
43 (0xffffc000337a9000) cpu1 terminated ?? at arch/x64/entry.S:101 vruntime 1372016024014862832
44 (0xffffc00033793000) cpu2 terminated ?? at arch/x64/entry.S:101 vruntime 1372016024783200136
45 (0xffffc0003377e000) cpu2 terminated ?? at arch/x64/entry.S:101 vruntime 1372016023507271733
46 (0xffffc00033769000) cpu2 terminated ?? at arch/x64/entry.S:101 vruntime 1372016024155354410
47 (0xffffc00033753000) cpu0 terminated ?? at arch/x64/entry.S:101 vruntime 1372016025922601336
48 (0xffffc0003373e000) cpu2 terminated ?? at arch/x64/entry.S:101 vruntime 1372016022280810107
49 (0xffffc00033729000) cpu0 terminated ?? at arch/x64/entry.S:101 vruntime 1372016023182387074
50 (0xffffc00033713000) cpu0 terminated ?? at arch/x64/entry.S:101 vruntime 1372016024034689208
51 (0xffffc000336fe000) cpu0 terminated ?? at arch/x64/entry.S:101 vruntime 1372016025329941850
52 (0xffffc000336e9000) cpu1 terminated ?? at arch/x64/entry.S:101 vruntime 1372016023366949297
53 (0xffffc000336d3000) cpu0 terminated ?? at arch/x64/entry.S:101 vruntime 1372016023013167672
54 (0xffffc000336be000) cpu1 terminated ?? at arch/x64/entry.S:101 vruntime 1372016024129763748

So it seems that 1 thread was successfully joined, but 19 weren't: The problem is that the 2nd thread remained in "terminating" state, so join() for it never finished; The other 18 successfully made it to the terminated state, but the test only joins them after joining the second thread, so it's not surprising that they don't get deleted and rather remain in "terminated" state.

The problem is why thread 36 remained in "terminating" state.
A bit more analysis:

The only place in the code we set "terminating" state is in thread::complete(), which then also sets _cpu->terminating_thread = this. We cannot run one and not the other because of the preempt_disable().
[TODO: assert that _cpu->terminating_thread == nullptr before; but how can it be not null?]

So we set _cpu->terminating_thread != null, but at the time of the hang, in thread 36, _cpu->terminating_thread==nullptr.
If _cpu hasn't changed (can it? I don't think we migrate non-queued threads), this means that we got to the only place in the code that resets terminating_thread it back to zero:
if (p->_cpu->terminating_thread) {
p->_cpu->terminating_thread->unref();
p->_cpu->terminating_thread = nullptr;
}
Which means unref() must have run, but done nothing. Printing the threads ref_count we indeed see 1 which means that either unref() wasn't run in the above code (how can that be possible?) or something else is keeping the thread's reference count up - but that shouldn't happen as all the other threads participating in our mutex wakeups are all done (terminated).

I need to tracepoints to understand what's happening, if I can reproduce this bug.

@ghost ghost assigned nyh Jun 24, 2013
@nyh
Copy link
Contributor Author

nyh commented Jun 24, 2013

The bug happened because complete() overwrote an existing _cpu->terminating_thread - causing this thread never to be terminated.
Normally, complete() doesn't get a chance to see a non-null _cpu->terminating_thread, because right after switching to any thread, we clear it. The problem is that we don't do this clearing on new threads (see switch_to_first()), so if a short-running new thread starts, and exits, in one time-slice, it will cause _cpu->terminating_thread to be overwritten.

A trivial solution (posted in a patch) is when we try to overwrite _cpu->terminating_thread, terminate the previous thread listed there first.

We don't need a more elaborate solution - if we want to be more elaborate, let's do issue #10 instead.

@nyh nyh closed this as completed Jun 24, 2013
nyh added a commit that referenced this issue Jun 24, 2013
This patch solves issue #11, where join() hangs were seen in tst-mutex, with
threads remaining in "terminating" state.

The problem was that complete() assumed that _cpu->terminating_thread was
nullptr, so it could overwrite it with the current thread. This is usually
true - when we switch to any thread, if terminating_thread!=0 it is
handled. The problem is that when we switch to a *new* thread (in
sched::init(), call switch_to_first()) this code does not run, and if
this thread quickly terminates, _cpu->terminating_thread gets overwritten
instead of being handled.

The simplest workaround, in this patch is simply to handle (i.e., call
unref()) the previous _cpu->terminating_thread before overwriting it.

The downside with this approach is that the termination of a thread
may be delayed by the run time of the first time-slice of a new thread.

But we anyway plan to eventually replace this termination mechanism
(see issue #10), so I think this solution is fine.
penberg pushed a commit that referenced this issue Aug 15, 2013
Building OSv with debug memory allocator enabled:

  $ make -j mode=debug conf-preempt=0 conf-debug_memory=1

Causes the guest to enter a busy loop right after JVM starts up:

  $ ./scripts/run.py -d

  [...]

  OpenJDK 64-Bit Server VM warning: Can't detect initial thread stack location - find_vma failed

GDB explains:

  #0  0x00000000003b5c54 in
boost::intrusive::rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::member_hook_traits<memory::page_range,
boost::intrusive::set_member_hook<boost::intrusive::none,
boost::intrusive::none, boost::intrusive::none, boost::intrusive::none>,
&memory::page_range::member_hook>, memory::addr_cmp, unsigned long, true>
>::private_erase (this=0x1d2f8c8 <memory::free_page_ranges+8>, b=..., e=...,
n=@0x3b40e9: 6179885759521391432) at
../../external/misc.bin/usr/include/boost/intrusive/rbtree.hpp:1417
  #1  0x00000000003b552e in
boost::intrusive::rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::member_hook_traits<memory::page_range,
boost::intrusive::set_member_hook<boost::intrusive::none,
boost::intrusive::none, boost::intrusive::none, boost::intrusive::none>,
&memory::page_range::member_hook>, memory::addr_cmp, unsigned long, true>
>::erase<memory::page_range, memory::addr_cmp>(memory::page_range const&,
memory::addr_cmp,
boost::intrusive::detail::enable_if_c<!boost::intrusive::detail::is_convertible<memory::addr_cmp,
boost::intrusive::tree_iterator<boost::intrusive::rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::member_hook_traits<memory::page_range,
boost::intrusive::set_member_hook<boost::intrusive::none,
boost::intrusive::none, boost::intrusive::none, boost::intrusive::none>,
&memory::page_range::member_hook>, memory::addr_cmp, unsigned long, true> >,
true> >::value, void>::type*) (this=0x1d2f8c0 <memory::free_page_ranges>,
key=..., comp=...) at
../../external/misc.bin/usr/include/boost/intrusive/rbtree.hpp:878
  #2  0x00000000003b4c4e in
boost::intrusive::rbtree_impl<boost::intrusive::setopt<boost::intrusive::detail::member_hook_traits<memory::page_range,
boost::intrusive::set_member_hook<boost::intrusive::none,
boost::intrusive::none, boost::intrusive::none, boost::intrusive::none>,
&memory::page_range::member_hook>, memory::addr_cmp, unsigned long, true>
>::erase (this=0x1d2f8c0 <memory::free_page_ranges>, value=...) at
../../external/misc.bin/usr/include/boost/intrusive/rbtree.hpp:856
  #3  0x00000000003b4145 in
boost::intrusive::set_impl<boost::intrusive::setopt<boost::intrusive::detail::member_hook_traits<memory::page_range,
boost::intrusive::set_member_hook<boost::intrusive::none,
boost::intrusive::none, boost::intrusive::none, boost::intrusive::none>,
&memory::page_range::member_hook>, memory::addr_cmp, unsigned long, true>
>::erase (this=0x1d2f8c0 <memory::free_page_ranges>, value=...) at
../../external/misc.bin/usr/include/boost/intrusive/set.hpp:601
  #4  0x00000000003b0130 in memory::refill_page_buffer () at ../../core/mempool.cc:487
  #5  0x00000000003b05f8 in memory::untracked_alloc_page () at ../../core/mempool.cc:569
  #6  0x00000000003b0631 in memory::alloc_page () at ../../core/mempool.cc:577
  #7  0x0000000000367a7c in mmu::populate::small_page (this=0x2000001fd460, ptep=..., offset=0) at ../../core/mmu.cc:456
  #8  0x0000000000365b00 in mmu::page_range_operation::operate_page
(this=0x2000001fd460, huge=false, addr=0xffffe0004ec9b000, offset=0) at
../../core/mmu.cc:438
  #9  0x0000000000365790 in mmu::page_range_operation::operate
(this=0x2000001fd460, start=0xffffe0004ec9b000, size=4096) at
../../core/mmu.cc:387
  #10 0x0000000000366148 in mmu::vpopulate (addr=0xffffe0004ec9b000, size=4096) at ../../core/mmu.cc:657
  #11 0x00000000003b0d8d in dbg::malloc (size=16) at ../../core/mempool.cc:818
  #12 0x00000000003b0f32 in malloc (size=16) at ../../core/mempool.cc:854

Fix the problem by checking if free_page_ranges is empty in
refill_page_buffer(). This fixes the busy loop issue and shows what's
really happening:

  OpenJDK 64-Bit Server VM warning: Can't detect initial thread stack location - find_vma failed
  alloc_page(): out of memory
  Aborted
penberg pushed a commit that referenced this issue Aug 16, 2013
Starting up Cassandra with debug memory allocator GPFs as follows:

  Breakpoint 1, abort () at ../../runtime.cc:85
  85	{
  (gdb) bt
  #0  abort () at ../../runtime.cc:85
  #1  0x0000000000375812 in osv::generate_signal (siginfo=..., ef=ef@entry=0xffffc0003ffe3008) at ../../libc/signal.cc:40
  #2  0x000000000037587c in osv::handle_segmentation_fault (addr=addr@entry=18446708889768681440, ef=ef@entry=0xffffc0003ffe3008)
      at ../../libc/signal.cc:55
  #3  0x00000000002fba02 in page_fault (ef=0xffffc0003ffe3008) at ../../core/mmu.cc:876
  #4  <signal handler called>
  #5  dbg::realloc (v=v@entry=0xffffe00019b3e000, size=size@entry=16) at ../../core/mempool.cc:846
  #6  0x000000000032654c in realloc (obj=0xffffe00019b3e000, size=16) at ../../core/mempool.cc:870
  #7  0x0000100000627743 in ?? ()
  #8  0x00002000001fe770 in ?? ()
  #9  0x00002000001fe780 in ?? ()
  #10 0x00002000001fe710 in ?? ()
  #11 0x00002000001fe700 in ?? ()
  #12 0xffffe000170e8000 in ?? ()
  #13 0x0000000200000001 in ?? ()
  #14 0x0000000000000020 in ?? ()
  #15 0x00002000001ffe70 in ?? ()
  #16 0xffffe000170e0004 in ?? ()
  #17 0x000000000036f361 in strcpy (dest=0x100001087420 "", src=<optimized out>) at ../../libc/string/strcpy.c:8
  #18 0x0000100000629b53 in ?? ()
  #19 0xffffe00019b22000 in ?? ()
  #20 0x0000000000000001 in ?? ()
  #21 0x0000000000000000 in ?? ()

The problem was introduced in commit 1ea5672 ("memory: let the debug
allocator mimic the standard allocator more closely") which forgot
to convert realloc() to use 'pad_before'.
penberg pushed a commit that referenced this issue Aug 26, 2013
If a crashed OSv guest is restarted, ZFS mount causes a GPF in early
startup:

  VFS: mounting zfs at /usr
  zfs: mounting osv/usr from device /dev/vblk1
  Aborted

GDB backtrace points finger at zfs_rmnode():

  #0  processor::halt_no_interrupts () at ../../arch/x64/processor.hh:212
  #1  0x00000000003e7f2a in osv::halt () at ../../core/power.cc:20
  #2  0x000000000021cdd4 in abort (msg=0x636df0 "Aborted\n") at ../../runtime.cc:95
  #3  0x000000000021cda2 in abort () at ../../runtime.cc:86
  #4  0x000000000044c149 in osv::generate_signal (siginfo=..., ef=0xffffc0003ffe7008) at ../../libc/signal.cc:44
  #5  0x000000000044c220 in osv::handle_segmentation_fault (addr=72, ef=0xffffc0003ffe7008) at ../../libc/signal.cc:55
  #6  0x0000000000366df3 in page_fault (ef=0xffffc0003ffe7008) at ../../core/mmu.cc:876
  #7  <signal handler called>
  #8  0x0000000000345eaa in zfs_rmnode (zp=0xffffc0003d1de400)
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_dir.c:611
  #9  0x000000000035650c in zfs_zinactive (zp=0xffffc0003d1de400)
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_znode.c:1355
  #10 0x0000000000345be1 in zfs_unlinked_drain (zfsvfs=0xffffc0003ddfe000)
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_dir.c:523
  #11 0x000000000034f45c in zfsvfs_setup (zfsvfs=0xffffc0003ddfe000, mounting=true)
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c:881
  #12 0x000000000034f7a4 in zfs_domount (vfsp=0xffffc0003de02000, osname=0x6b14cb "osv/usr")
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c:1016
  #13 0x000000000034f98c in zfs_mount (mp=0xffffc0003de02000, dev=0x6b14d7 "/dev/vblk1", flags=0, data=0x6b14cb)
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c:1415
  #14 0x0000000000406852 in sys_mount (dev=0x6b14d7 "/dev/vblk1", dir=0x6b14a3 "/usr", fsname=0x6b14d3 "zfs", flags=0, data=0x6b14cb)
      at ../../fs/vfs/vfs_mount.c:171
  #15 0x00000000003eff97 in mount_usr () at ../../fs/vfs/main.cc:1415
  #16 0x0000000000203a89 in do_main_thread (_args=0xffffc0003fe9ced0) at ../../loader.cc:215
  #17 0x0000000000448575 in pthread_private::pthread::pthread(void* (*)(void*), void*, sigset_t, pthread_private::thread_attr const*)::{lambda()#1}::operator()() const () at ../../libc/pthread.cc:59
  #18 0x00000000004499d3 in std::_Function_handler<void(), pthread_private::pthread::pthread(void* (*)(void*), void*, sigset_t, const pthread_private::thread_attr*)::__lambda0>::_M_invoke(const std::_Any_data &) (__functor=...)
      at ../../external/gcc.bin/usr/include/c++/4.8.1/functional:2071
  #19 0x000000000037e602 in std::function<void ()>::operator()() const (this=0xffffc0003e170038)
      at ../../external/gcc.bin/usr/include/c++/4.8.1/functional:2468
  #20 0x00000000003bae3e in sched::thread::main (this=0xffffc0003e170010) at ../../core/sched.cc:581
  #21 0x00000000003b8c92 in sched::thread_main_c (t=0xffffc0003e170010) at ../../arch/x64/arch-switch.hh:133
  #22 0x0000000000399c8e in thread_main () at ../../arch/x64/entry.S:101

The problem is that ZFS tries to check if the znode is an attribute
directory and trips over zp->z_vnode being NULL.  However, as explained
in commit b7ee91e ("zfs: port vop_lookup"), we don't even support
extended attributes so drop the check completely for OSv.
penberg pushed a commit that referenced this issue Aug 26, 2013
If a crashed OSv guest is restarted, ZFS mount causes a GPF in early
startup:

  VFS: mounting zfs at /usr
  zfs: mounting osv/usr from device /dev/vblk1
  Aborted

GDB backtrace points finger at zfs_rmnode():

  #0  processor::halt_no_interrupts () at ../../arch/x64/processor.hh:212
  #1  0x00000000003e7f2a in osv::halt () at ../../core/power.cc:20
  #2  0x000000000021cdd4 in abort (msg=0x636df0 "Aborted\n") at ../../runtime.cc:95
  #3  0x000000000021cda2 in abort () at ../../runtime.cc:86
  #4  0x000000000044c149 in osv::generate_signal (siginfo=..., ef=0xffffc0003ffe7008) at ../../libc/signal.cc:44
  #5  0x000000000044c220 in osv::handle_segmentation_fault (addr=72, ef=0xffffc0003ffe7008) at ../../libc/signal.cc:55
  #6  0x0000000000366df3 in page_fault (ef=0xffffc0003ffe7008) at ../../core/mmu.cc:876
  #7  <signal handler called>
  #8  0x0000000000345eaa in zfs_rmnode (zp=0xffffc0003d1de400)
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_dir.c:611
  #9  0x000000000035650c in zfs_zinactive (zp=0xffffc0003d1de400)
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_znode.c:1355
  #10 0x0000000000345be1 in zfs_unlinked_drain (zfsvfs=0xffffc0003ddfe000)
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_dir.c:523
  #11 0x000000000034f45c in zfsvfs_setup (zfsvfs=0xffffc0003ddfe000, mounting=true)
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c:881
  #12 0x000000000034f7a4 in zfs_domount (vfsp=0xffffc0003de02000, osname=0x6b14cb "osv/usr")
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c:1016
  #13 0x000000000034f98c in zfs_mount (mp=0xffffc0003de02000, dev=0x6b14d7 "/dev/vblk1", flags=0, data=0x6b14cb)
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c:1415
  #14 0x0000000000406852 in sys_mount (dev=0x6b14d7 "/dev/vblk1", dir=0x6b14a3 "/usr", fsname=0x6b14d3 "zfs", flags=0, data=0x6b14cb)
      at ../../fs/vfs/vfs_mount.c:171
  #15 0x00000000003eff97 in mount_usr () at ../../fs/vfs/main.cc:1415
  #16 0x0000000000203a89 in do_main_thread (_args=0xffffc0003fe9ced0) at ../../loader.cc:215
  #17 0x0000000000448575 in pthread_private::pthread::pthread(void* (*)(void*), void*, sigset_t, pthread_private::thread_attr const*)::{lambda()#1}::operator()() const () at ../../libc/pthread.cc:59
  #18 0x00000000004499d3 in std::_Function_handler<void(), pthread_private::pthread::pthread(void* (*)(void*), void*, sigset_t, const pthread_private::thread_attr*)::__lambda0>::_M_invoke(const std::_Any_data &) (__functor=...)
      at ../../external/gcc.bin/usr/include/c++/4.8.1/functional:2071
  #19 0x000000000037e602 in std::function<void ()>::operator()() const (this=0xffffc0003e170038)
      at ../../external/gcc.bin/usr/include/c++/4.8.1/functional:2468
  #20 0x00000000003bae3e in sched::thread::main (this=0xffffc0003e170010) at ../../core/sched.cc:581
  #21 0x00000000003b8c92 in sched::thread_main_c (t=0xffffc0003e170010) at ../../arch/x64/arch-switch.hh:133
  #22 0x0000000000399c8e in thread_main () at ../../arch/x64/entry.S:101

The problem is that ZFS tries to check if the znode is an attribute
directory and trips over zp->z_vnode being NULL.  However, as explained
in commit b7ee91e ("zfs: port vop_lookup"), we don't even support
extended attributes so drop the check completely for OSv.
penberg pushed a commit that referenced this issue Aug 26, 2013
Fix mincore() to deal with unmapped addresses like msync() does.

This fixes a SIGSEGV in libunwind's access_mem() when leak detector is
enabled:

   (gdb) bt
  #0  page_fault (ef=0xffffc0003ffe7008) at ../../core/mmu.cc:871
  #1  <signal handler called>
  #2  ContiguousSpace::block_start_const (this=<optimized out>, p=0x77d2f3968)
      at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/oops/oop.inline.hpp:411
  #3  0x00001000008ae16c in GenerationBlockStartClosure::do_space (this=0x2000001f9100, s=<optimized out>)
      at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/memory/generation.cpp:242
  #4  0x00001000007f097c in DefNewGeneration::space_iterate (this=0xffffc0003fb68c00, blk=0x2000001f9100, usedOnly=<optimized out>)
      at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/memory/defNewGeneration.cpp:480
  #5  0x00001000008aca0e in Generation::block_start (this=<optimized out>, p=<optimized out>)
      at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/memory/generation.cpp:251
  #6  0x0000100000b06d2f in os::print_location (st=st@entry=0x2000001f9560, x=32165017960, verbose=verbose@entry=false)
      at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/runtime/os.cpp:868
  #7  0x0000100000b11b5b in os::print_register_info (st=0x2000001f9560, context=0x2000001f9740)
      at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/os_cpu/linux_x86/vm/os_linux_x86.cpp:839
  #8  0x0000100000c6cde8 in VMError::report (this=0x2000001f9610, st=st@entry=0x2000001f9560)
      at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/utilities/vmError.cpp:551
  #9  0x0000100000c6da3b in VMError::report_and_die (this=this@entry=0x2000001f9610)
      at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/utilities/vmError.cpp:984
  #10 0x0000100000b1109f in JVM_handle_linux_signal (sig=11, info=0x2000001f9bb8, ucVoid=0x2000001f9740,
      abort_if_unrecognized=<optimized out>)
      at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/os_cpu/linux_x86/vm/os_linux_x86.cpp:528
  #11 0x000000000039f242 in call_signal_handler (frame=0x2000001f9b10) at ../../arch/x64/signal.cc:69
  #12 <signal handler called>
  #13 0x000000000057d721 in access_mem ()
  #14 0x000000000057cb1d in dwarf_get ()
  #15 0x000000000057ce51 in _ULx86_64_step ()
  #16 0x00000000004315fd in backtrace (buffer=0x1ff9d80 <memory::alloc_tracker::remember(void*, int)::bt>, size=20)
      at ../../libc/misc/backtrace.cc:16
  #17 0x00000000003b8d99 in memory::alloc_tracker::remember (this=0x1777ae0 <memory::tracker>, addr=0xffffc0004508de00, size=54)
      at ../../core/alloctracker.cc:59
  #18 0x00000000003b0504 in memory::tracker_remember (addr=0xffffc0004508de00, size=54) at ../../core/mempool.cc:43
  #19 0x00000000003b2152 in std_malloc (size=54) at ../../core/mempool.cc:723
  #20 0x00000000003b259c in malloc (size=54) at ../../core/mempool.cc:856
  #21 0x0000100001615e4c in JNU_GetStringPlatformChars (env=env@entry=0xffffc0003a4dc1d8, jstr=jstr@entry=0xffffc0004591b800,
      isCopy=isCopy@entry=0x0) at ../../../src/share/native/common/jni_util.c:801
  #22 0x000010000161ada6 in Java_java_io_UnixFileSystem_getBooleanAttributes0 (env=0xffffc0003a4dc1d8, this=<optimized out>,
      file=<optimized out>) at ../../../src/solaris/native/java/io/UnixFileSystem_md.c:111
  #23 0x000020000021ed8e in ?? ()
  #24 0x00002000001faa58 in ?? ()
  #25 0x00002000001faac0 in ?? ()
  #26 0x00002000001faa50 in ?? ()
  #27 0x0000000000000000 in ?? ()

Spotted by Avi Kivity.
penberg pushed a commit that referenced this issue Sep 3, 2013
If "-javaagent" option is enabled, the JVM page faults:

  (gdb) bt
  #0  0x000000000033d432 in halt_no_interrupts () at ../../arch/x64/processor.hh:232
  #1  osv::halt () at ../../core/power.cc:20
  #2  0x0000000000214d82 in abort (msg=msg@entry=0x57ea90 "page fault outside application") at ../../runtime.cc:98
  #3  0x00000000002fd4d8 in page_fault (ef=0xffffc0003ffe6008) at ../../core/mmu.cc:943
  #4  <signal handler called>
  #5  0x0000000000373169 in __stpncpy (d=d@entry=0x2000001fe7f0 "dlsym: symbol JVM_begin_signal_setting not found", s=0x0, n=1023)
      at ../../libc/string/stpncpy.c:19
  #6  0x0000000000373ad1 in strncpy (d=0x2000001fe7f0 "dlsym: symbol JVM_begin_signal_setting not found", s=<optimized out>,
      n=<optimized out>) at ../../libc/string/strncpy.c:7
  #7  0x0000100000b0ab67 in os::dll_load (filename=filename@entry=0x2000001febf0 "libinstrument.so",
      ebuf=ebuf@entry=0x2000001fe7f0 "dlsym: symbol JVM_begin_signal_setting not found", ebuflen=ebuflen@entry=1024)
      at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/os/linux/vm/os_linux.cpp:1841
  #8  0x0000100000c247eb in lookup_on_load (agent=agent@entry=0xffffc0003976ccc0,
      on_load_symbols=on_load_symbols@entry=0x2000001ffd40, num_symbol_entries=1)
      at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/runtime/thread.cpp:3585
  #9  0x0000100000c2a64f in lookup_agent_on_load (agent=0xffffc0003976ccc0)
      at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/runtime/thread.cpp:3617
  #10 create_vm_init_agents ()
      at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/runtime/thread.cpp:3656
  #11 Threads::create_vm (args=<optimized out>, canTryAgain=canTryAgain@entry=0x2000001ffdb0)
      at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/runtime/thread.cpp:3177
  #12 0x000010000094d7b0 in JNI_CreateJavaVM (vm=0x2000001ffe58, penv=0x2000001ffe60, args=<optimized out>)
      at /usr/src/debug/java-1.7.0-openjdk-1.7.0.25-2.3.12.3.fc19.x86_64/openjdk/hotspot/src/share/vm/prims/jni.cpp:5127
  #13 0x0000100000007b3b in main (argc=<optimized out>, argv=0xffffc0003fff2008) at ../../java/java.cc:73
  #14 0x0000000000208ac8 in run_main (prog=<optimized out>, args=args@entry=0xffffc0003fe9bfa0) at ../../loader.cc:196
  #15 0x0000000000208c68 in do_main_thread (_args=0xffffc0003fe9bfa0) at ../../loader.cc:217
  #16 0x0000000000376d36 in operator() (__closure=0xffffc0003b5e2a00) at ../../libc/pthread.cc:59
  #17 std::_Function_handler<void(), pthread_private::pthread::pthread(void* (*)(void*), void*, sigset_t, const pthread_private::thread_attr*)::__lambda0>::_M_invoke(const std::_Any_data &) (__functor=...) at ../../external/gcc.bin/usr/include/c++/4.8.1/functional:2071
  #18 0x000000000032ed6b in main (this=0xffffc0003a807010) at ../../core/sched.cc:536
  #19 sched::thread_main_c (t=0xffffc0003a807010) at ../../arch/x64/arch-switch.hh:133
  #20 0x000000000031873e in thread_main () at ../../arch/x64/entry.S:101
  Backtrace stopped: frame did not save the PC

This is caused by the JVM expecting dlerror() to return an error string
if dlopen() fails. Fix that up.
penberg pushed a commit that referenced this issue Dec 23, 2013
I saw this Abort:

35.159 Mb/s
50.230 Mb/s
46.648 Mb/s
68.850 Mb/s
Wrote 613.418 MB in 10.00 s
Aborted

The backtrace says:

  (gdb) bt
  #0  0x000000000035bb82 in halt_no_interrupts () at
  /home/asias/src/cloudius-systems/osv/arch/x64/processor.hh:241
  #1  osv::halt () at
  /home/asias/src/cloudius-systems/osv/core/power.cc:28
  #2  0x0000000000218142 in abort (msg=msg@entry=0x55197f "Aborted\n") at
  /home/asias/src/cloudius-systems/osv/runtime.cc:89
  #3  0x000000000021816e in abort () at
  /home/asias/src/cloudius-systems/osv/runtime.cc:79
  #4  0x000000000039eaa2 in osv::generate_signal (siginfo=...,
  ef=0xffffc0003eb56008) at
  /home/asias/src/cloudius-systems/osv/libc/signal.cc:58
  #5  0x000000000039eb0c in osv::handle_segmentation_fault
  (addr=<optimized out>, ef=<optimized out>) at
  /home/asias/src/cloudius-systems/osv/libc/signal.cc:73
  #6  0x000000000030b45c in mmu::vm_sigsegv
  (addr=addr@entry=17592186060800, ef=ef@entry=0xffffc0003eb56008) at
  /home/asias/src/cloudius-systems/osv/core/mmu.cc:763
  #7  0x000000000030b54b in mmu::vm_fault (addr=<optimized out>,
  addr@entry=17592186061840, ef=ef@entry=0xffffc0003eb56008)
      at /home/asias/src/cloudius-systems/osv/core/mmu.cc:773
  #8  0x000000000032bff5 in page_fault (ef=0xffffc0003eb56008) at
  /home/asias/src/cloudius-systems/osv/arch/x64/mmu.cc:35
  #9  <signal handler called>
  #10 0x0000100000004410 in ?? ()
  #11 0x000000000031e5fd in virtio::blk::req_done
  (this=0xffffc0003eddb800) at
  /home/asias/src/cloudius-systems/osv/drivers/virtio-blk.

Wait until all the bio are done to fix this use after free.

This patch also make the test to measure completed writes instead of
submitted writes.

Reviewed-by: Tomasz Grabiec <[email protected]>
Signed-off-by: Asias He <[email protected]>
Signed-off-by: Pekka Enberg <[email protected]>
penberg pushed a commit that referenced this issue Jul 17, 2014
This reverts commit 902535a.

Raphael reports the following breakage in tst-poll.so:

  OSv
  ---

    TEST tst-nway-merger.so        OK  (0.782 s)
    TEST tst-openat.so             OK  (0.731 s)
    TEST tst-pipe.so               OK  (6.840 s)
    TEST tst-poll.so              OSv v0.10-319-g1bdd4a2
  eth0: 192.168.122.15
  Running 3 test cases...
  Assertion failed: tp->t_flags & 0x1000000
  (/data/osv/bsd/sys/netinet/tcp_timer.cc: tcp_timer_tso_flush: 438)

  [backtrace]
  0x0000000000223e98 <__assert_fail+24>
  0x0000000000279de4 <???+2596324>
  0x00000000003dbd9d <async::timer_task::fire(async::percpu_timer_task&)+125>
  0x00000000003dcb13 <async::async_worker::run()+1587>
  0x00000000003be11a <thread_main_c+26>
  0x0000000000372525 <???+3613989>

  GDB
  ---

  (gdb) bt
  #0  0x00000000003d2a72 in cli_hlt () at /data/osv/arch/x64/processor.hh:242
  #1  halt_no_interrupts () at /data/osv/arch/x64/arch.hh:48
  #2  osv::halt () at /data/osv/core/power.cc:34
  #3  0x0000000000223df0 in abort (fmt=fmt@entry=0x5c9980 "Assertion
  failed: %s (%s: %s: %d)\n") at /data/osv/runtime.cc:139
  #4  0x0000000000223e99 in __assert_fail (expr=<optimized out>,
  file=<optimized out>, line=<optimized out>, func=<optimized out>)
      at /data/osv/runtime.cc:145
  #5  0x0000000000279de5 in tcp_timer_tso_flush (timer=...,
  tp=0xffffa0003db51800) at /data/osv/bsd/sys/netinet/tcp_timer.cc:438
  #6  0x00000000003dbd9e in async::timer_task::fire
  (this=this@entry=0xffffa0003d6b9a10, task=...) at
  /data/osv/core/async.cc:362
  #7  0x00000000003dcb14 in fire (task=..., this=0xffff80003fa84030) at
  /data/osv/core/async.cc:227
  #8  async::async_worker::run (this=0xffff80003fa84030) at
  /data/osv/core/async.cc:175
  #9  0x00000000003be11b in main (this=0xffff80003fa84730) at
  /data/osv/core/sched.cc:915
  #10 sched::thread_main_c (t=0xffff80003fa84730) at
  /data/osv/arch/x64/arch-switch.hh:137
  #11 0x0000000000372526 in thread_main () at /data/osv/arch/x64/entry.S:113
  (gdb) print tp->t_flags
  No symbol "tp" in current context.
  (gdb) frame 5
  #5  0x0000000000279de5 in tcp_timer_tso_flush (timer=...,
  tp=0xffffa0003db51800) at /data/osv/bsd/sys/netinet/tcp_timer.cc:438
  438     KASSERT(tp->t_flags & TF_TSO, "tcp_timer_tso_flush: TSO disabled");
  (gdb) print tp->t_flags
  $1 = 992

Signed-off-by: Pekka Enberg <[email protected]>
asias added a commit to asias/osv that referenced this issue Aug 28, 2014
   $ sudo scripts/run.py -c1 -nv -m4g  -e "/tests/tst-epoll.so"
   ...

   PASS: epoll_wait
   PASS: write
   PASS: epoll_wait
   PASS: epoll_ctl MOD
   PASS: epoll_wait
   PASS: epoll_ctl ADD
   PASS: errno == EEXIST
   Assertion failed: i != f_epolls->end() (/home/asias/src/cloudius-systems/osv/fs/vfs/kern_descrip.cc: epoll_del: 249)

   [backtrace]
   0x0000000000223648 <__assert_fail+24>
   0x000000000041743a <file::epoll_del(epoll_ptr)+186>
   0x00000000003f7682 <epoll_ctl+786>
   0x0000100000c032db <???+12595931>
   0x000000000040510a <osv::application::run_main(std::string, int, char**)+266>
   0x0000000000405847 <osv::application::run_main()+551>
   0x000000000020bbd1 <osv::application::main()+97>
   0x0000000000406698 <???+4220568>
   0x0000000000433745 <???+4405061>
   0x00000000003e38aa <thread_main_c+26>
   0x0000000000389c75 <???+3710069>

   (gdb) bt
   #0  0x00000000003f8e92 in cli_hlt () at /home/asias/src/cloudius-systems/osv/arch/x64/processor.hh:242
   cloudius-systems#1  halt_no_interrupts () at /home/asias/src/cloudius-systems/osv/arch/x64/arch.hh:49
   cloudius-systems#2  osv::halt () at /home/asias/src/cloudius-systems/osv/core/power.cc:34
   cloudius-systems#3  0x000000000022360f in abort (fmt=fmt@entry=0x603b60 "Assertion failed: %s (%s: %s: %d)\n") at /home/asias/src/cloudius-systems/osv/runtime.cc:150
   cloudius-systems#4  0x0000000000223649 in __assert_fail (expr=<optimized out>, file=<optimized out>, line=<optimized out>, func=<optimized out>)
       at /home/asias/src/cloudius-systems/osv/runtime.cc:156
   cloudius-systems#5  0x000000000041743b in file::epoll_del (this=<optimized out>, ep=...) at /home/asias/src/cloudius-systems/osv/fs/vfs/kern_descrip.cc:249
   cloudius-systems#6  0x00000000003f7683 in del (key=..., this=0xffff800001746040) at /home/asias/src/cloudius-systems/osv/core/epoll.cc:96
   cloudius-systems#7  epoll_ctl (epfd=<optimized out>, op=<optimized out>, fd=<optimized out>, event=0x2000002f9d50) at /home/asias/src/cloudius-systems/osv/core/epoll.cc:283
   cloudius-systems#8  0x0000100000c032dc in test_epolloneshot () at /home/asias/src/cloudius-systems/osv/tests/tst-epoll.cc:78
   cloudius-systems#9  main (ac=<optimized out>, av=<optimized out>) at /home/asias/src/cloudius-systems/osv/tests/tst-epoll.cc:231
   cloudius-systems#10 0x000000000040510b in osv::application::run_main (this=this@entry=0xffffa00001561f18, path="/tests/tst-epoll.so", argc=argc@entry=1,
       argv=argv@entry=0xffffa00002994760) at /home/asias/src/cloudius-systems/osv/core/app.cc:182
   cloudius-systems#11 0x0000000000405848 in osv::application::run_main (this=this@entry=0xffffa00001561f18) at /home/asias/src/cloudius-systems/osv/core/app.cc:197
   cloudius-systems#12 0x000000000020bbd2 in osv::application::main (this=0xffffa00001561f18) at /home/asias/src/cloudius-systems/osv/core/app.cc:144
   cloudius-systems#13 0x0000000000406699 in operator() (__closure=0x0, app=<optimized out>) at /home/asias/src/cloudius-systems/osv/core/app.cc:104
   cloudius-systems#14 osv::application::__lambda3::_FUN (app=<optimized out>) at /home/asias/src/cloudius-systems/osv/core/app.cc:106
   cloudius-systems#15 0x0000000000433746 in operator() (__closure=0xffffa00003320600) at /home/asias/src/cloudius-systems/osv/libc/pthread.cc:97
   cloudius-systems#16 std::_Function_handler<void(), pthread_private::pthread::pthread(void* (*)(void*), void*, sigset_t, const pthread_private::thread_attr*)::__lambda7>::_M_invoke(const std::_Any_data &) (__functor=...) at /home/asias/src/cloudius-systems/osv/external/x64/gcc.bin/usr/include/c++/4.8.2/functional:2071
   cloudius-systems#17 0x00000000003e38ab in main (this=0xffff80000354d050) at /home/asias/src/cloudius-systems/osv/core/sched.cc:940
   cloudius-systems#18 sched::thread_main_c (t=0xffff80000354d050) at /home/asias/src/cloudius-systems/osv/arch/x64/arch-switch.hh:137
   cloudius-systems#19 0x0000000000389c76 in thread_main () at /home/asias/src/cloudius-systems/osv/arch/x64/entry.S:113
asias added a commit to asias/osv that referenced this issue Aug 28, 2014
After:
    Revert "Revert "epoll: fix up lock ordering issues""
    This reverts commit 408a982.

I saw the following without this patch:

   $ sudo scripts/run.py -c1 -nv -m4g  -e "/tests/tst-epoll.so"
   ...

   PASS: epoll_wait
   PASS: write
   PASS: epoll_wait
   PASS: epoll_ctl MOD
   PASS: epoll_wait
   PASS: epoll_ctl ADD
   PASS: errno == EEXIST
   Assertion failed: i != f_epolls->end() (/home/asias/src/cloudius-systems/osv/fs/vfs/kern_descrip.cc: epoll_del: 249)

   [backtrace]
   0x0000000000223648 <__assert_fail+24>
   0x000000000041743a <file::epoll_del(epoll_ptr)+186>
   0x00000000003f7682 <epoll_ctl+786>
   0x0000100000c032db <???+12595931>
   0x000000000040510a <osv::application::run_main(std::string, int, char**)+266>
   0x0000000000405847 <osv::application::run_main()+551>
   0x000000000020bbd1 <osv::application::main()+97>
   0x0000000000406698 <???+4220568>
   0x0000000000433745 <???+4405061>
   0x00000000003e38aa <thread_main_c+26>
   0x0000000000389c75 <???+3710069>

   (gdb) bt
   #0  0x00000000003f8e92 in cli_hlt () at /home/asias/src/cloudius-systems/osv/arch/x64/processor.hh:242
   cloudius-systems#1  halt_no_interrupts () at /home/asias/src/cloudius-systems/osv/arch/x64/arch.hh:49
   cloudius-systems#2  osv::halt () at /home/asias/src/cloudius-systems/osv/core/power.cc:34
   cloudius-systems#3  0x000000000022360f in abort (fmt=fmt@entry=0x603b60 "Assertion failed: %s (%s: %s: %d)\n") at /home/asias/src/cloudius-systems/osv/runtime.cc:150
   cloudius-systems#4  0x0000000000223649 in __assert_fail (expr=<optimized out>, file=<optimized out>, line=<optimized out>, func=<optimized out>)
       at /home/asias/src/cloudius-systems/osv/runtime.cc:156
   cloudius-systems#5  0x000000000041743b in file::epoll_del (this=<optimized out>, ep=...) at /home/asias/src/cloudius-systems/osv/fs/vfs/kern_descrip.cc:249
   cloudius-systems#6  0x00000000003f7683 in del (key=..., this=0xffff800001746040) at /home/asias/src/cloudius-systems/osv/core/epoll.cc:96
   cloudius-systems#7  epoll_ctl (epfd=<optimized out>, op=<optimized out>, fd=<optimized out>, event=0x2000002f9d50) at /home/asias/src/cloudius-systems/osv/core/epoll.cc:283
   cloudius-systems#8  0x0000100000c032dc in test_epolloneshot () at /home/asias/src/cloudius-systems/osv/tests/tst-epoll.cc:78
   cloudius-systems#9  main (ac=<optimized out>, av=<optimized out>) at /home/asias/src/cloudius-systems/osv/tests/tst-epoll.cc:231
   cloudius-systems#10 0x000000000040510b in osv::application::run_main (this=this@entry=0xffffa00001561f18, path="/tests/tst-epoll.so", argc=argc@entry=1,
       argv=argv@entry=0xffffa00002994760) at /home/asias/src/cloudius-systems/osv/core/app.cc:182
   cloudius-systems#11 0x0000000000405848 in osv::application::run_main (this=this@entry=0xffffa00001561f18) at /home/asias/src/cloudius-systems/osv/core/app.cc:197
   cloudius-systems#12 0x000000000020bbd2 in osv::application::main (this=0xffffa00001561f18) at /home/asias/src/cloudius-systems/osv/core/app.cc:144
   cloudius-systems#13 0x0000000000406699 in operator() (__closure=0x0, app=<optimized out>) at /home/asias/src/cloudius-systems/osv/core/app.cc:104
   cloudius-systems#14 osv::application::__lambda3::_FUN (app=<optimized out>) at /home/asias/src/cloudius-systems/osv/core/app.cc:106
   cloudius-systems#15 0x0000000000433746 in operator() (__closure=0xffffa00003320600) at /home/asias/src/cloudius-systems/osv/libc/pthread.cc:97
   cloudius-systems#16 std::_Function_handler<void(), pthread_private::pthread::pthread(void* (*)(void*), void*, sigset_t, const pthread_private::thread_attr*)::__lambda7>::_M_invoke(const std::_Any_data &) (__functor=...) at /home/asias/src/cloudius-systems/osv/external/x64/gcc.bin/usr/include/c++/4.8.2/functional:2071
   cloudius-systems#17 0x00000000003e38ab in main (this=0xffff80000354d050) at /home/asias/src/cloudius-systems/osv/core/sched.cc:940
   cloudius-systems#18 sched::thread_main_c (t=0xffff80000354d050) at /home/asias/src/cloudius-systems/osv/arch/x64/arch-switch.hh:137
   cloudius-systems#19 0x0000000000389c76 in thread_main () at /home/asias/src/cloudius-systems/osv/arch/x64/entry.S:113
asias added a commit to asias/osv that referenced this issue Aug 28, 2014
The problem is that when epoll_wait removes the key from _file map, it
does not remove the key from _epoll map, so when epoll_ctrl(DEL) tries
to remove _file_map again, we hit the assert.

This fixes the following.

After:
    Revert "Revert "epoll: fix up lock ordering issues""

I saw:

   $ sudo scripts/run.py -c1 -nv -m4g  -e "/tests/tst-epoll.so"
   ...

   PASS: epoll_wait
   PASS: write
   PASS: epoll_wait
   PASS: epoll_ctl MOD
   PASS: epoll_wait
   PASS: epoll_ctl ADD
   PASS: errno == EEXIST
   Assertion failed: i != f_epolls->end() (/home/asias/src/cloudius-systems/osv/fs/vfs/kern_descrip.cc: epoll_del: 249)

   [backtrace]
   0x0000000000223648 <__assert_fail+24>
   0x000000000041743a <file::epoll_del(epoll_ptr)+186>
   0x00000000003f7682 <epoll_ctl+786>
   0x0000100000c032db <???+12595931>
   0x000000000040510a <osv::application::run_main(std::string, int, char**)+266>
   0x0000000000405847 <osv::application::run_main()+551>
   0x000000000020bbd1 <osv::application::main()+97>
   0x0000000000406698 <???+4220568>
   0x0000000000433745 <???+4405061>
   0x00000000003e38aa <thread_main_c+26>
   0x0000000000389c75 <???+3710069>

   (gdb) bt
   #0  0x00000000003f8e92 in cli_hlt () at /home/asias/src/cloudius-systems/osv/arch/x64/processor.hh:242
   cloudius-systems#1  halt_no_interrupts () at /home/asias/src/cloudius-systems/osv/arch/x64/arch.hh:49
   cloudius-systems#2  osv::halt () at /home/asias/src/cloudius-systems/osv/core/power.cc:34
   cloudius-systems#3  0x000000000022360f in abort (fmt=fmt@entry=0x603b60 "Assertion failed: %s (%s: %s: %d)\n") at /home/asias/src/cloudius-systems/osv/runtime.cc:150
   cloudius-systems#4  0x0000000000223649 in __assert_fail (expr=<optimized out>, file=<optimized out>, line=<optimized out>, func=<optimized out>)
       at /home/asias/src/cloudius-systems/osv/runtime.cc:156
   cloudius-systems#5  0x000000000041743b in file::epoll_del (this=<optimized out>, ep=...) at /home/asias/src/cloudius-systems/osv/fs/vfs/kern_descrip.cc:249
   cloudius-systems#6  0x00000000003f7683 in del (key=..., this=0xffff800001746040) at /home/asias/src/cloudius-systems/osv/core/epoll.cc:96
   cloudius-systems#7  epoll_ctl (epfd=<optimized out>, op=<optimized out>, fd=<optimized out>, event=0x2000002f9d50) at /home/asias/src/cloudius-systems/osv/core/epoll.cc:283
   cloudius-systems#8  0x0000100000c032dc in test_epolloneshot () at /home/asias/src/cloudius-systems/osv/tests/tst-epoll.cc:78
   cloudius-systems#9  main (ac=<optimized out>, av=<optimized out>) at /home/asias/src/cloudius-systems/osv/tests/tst-epoll.cc:231
   cloudius-systems#10 0x000000000040510b in osv::application::run_main (this=this@entry=0xffffa00001561f18, path="/tests/tst-epoll.so", argc=argc@entry=1,
       argv=argv@entry=0xffffa00002994760) at /home/asias/src/cloudius-systems/osv/core/app.cc:182
   cloudius-systems#11 0x0000000000405848 in osv::application::run_main (this=this@entry=0xffffa00001561f18) at /home/asias/src/cloudius-systems/osv/core/app.cc:197
   cloudius-systems#12 0x000000000020bbd2 in osv::application::main (this=0xffffa00001561f18) at /home/asias/src/cloudius-systems/osv/core/app.cc:144
   cloudius-systems#13 0x0000000000406699 in operator() (__closure=0x0, app=<optimized out>) at /home/asias/src/cloudius-systems/osv/core/app.cc:104
   cloudius-systems#14 osv::application::__lambda3::_FUN (app=<optimized out>) at /home/asias/src/cloudius-systems/osv/core/app.cc:106
   cloudius-systems#15 0x0000000000433746 in operator() (__closure=0xffffa00003320600) at /home/asias/src/cloudius-systems/osv/libc/pthread.cc:97
   cloudius-systems#16 std::_Function_handler<void(), pthread_private::pthread::pthread(void* (*)(void*), void*, sigset_t, const pthread_private::thread_attr*)::__lambda7>::_M_invoke(const std::_Any_data &) (__functor=...) at /home/asias/src/cloudius-systems/osv/external/x64/gcc.bin/usr/include/c++/4.8.2/functional:2071
   cloudius-systems#17 0x00000000003e38ab in main (this=0xffff80000354d050) at /home/asias/src/cloudius-systems/osv/core/sched.cc:940
   cloudius-systems#18 sched::thread_main_c (t=0xffff80000354d050) at /home/asias/src/cloudius-systems/osv/arch/x64/arch-switch.hh:137
   cloudius-systems#19 0x0000000000389c76 in thread_main () at /home/asias/src/cloudius-systems/osv/arch/x64/entry.S:113

Signed-off-by: Asias He <[email protected]>
avikivity pushed a commit that referenced this issue Aug 28, 2014
The problem is that when epoll_wait removes the key from _file map, it
does not remove the key from _epoll map, so when epoll_ctrl(DEL) tries
to remove _file_map again, we hit the assert.

This fixes the following.

After:
    Revert "Revert "epoll: fix up lock ordering issues""

I saw:

   $ sudo scripts/run.py -c1 -nv -m4g  -e "/tests/tst-epoll.so"
   ...

   PASS: epoll_wait
   PASS: write
   PASS: epoll_wait
   PASS: epoll_ctl MOD
   PASS: epoll_wait
   PASS: epoll_ctl ADD
   PASS: errno == EEXIST
   Assertion failed: i != f_epolls->end() (/home/asias/src/cloudius-systems/osv/fs/vfs/kern_descrip.cc: epoll_del: 249)

   [backtrace]
   0x0000000000223648 <__assert_fail+24>
   0x000000000041743a <file::epoll_del(epoll_ptr)+186>
   0x00000000003f7682 <epoll_ctl+786>
   0x0000100000c032db <???+12595931>
   0x000000000040510a <osv::application::run_main(std::string, int, char**)+266>
   0x0000000000405847 <osv::application::run_main()+551>
   0x000000000020bbd1 <osv::application::main()+97>
   0x0000000000406698 <???+4220568>
   0x0000000000433745 <???+4405061>
   0x00000000003e38aa <thread_main_c+26>
   0x0000000000389c75 <???+3710069>

   (gdb) bt
   #0  0x00000000003f8e92 in cli_hlt () at /home/asias/src/cloudius-systems/osv/arch/x64/processor.hh:242
   #1  halt_no_interrupts () at /home/asias/src/cloudius-systems/osv/arch/x64/arch.hh:49
   #2  osv::halt () at /home/asias/src/cloudius-systems/osv/core/power.cc:34
   #3  0x000000000022360f in abort (fmt=fmt@entry=0x603b60 "Assertion failed: %s (%s: %s: %d)\n") at /home/asias/src/cloudius-systems/osv/runtime.cc:150
   #4  0x0000000000223649 in __assert_fail (expr=<optimized out>, file=<optimized out>, line=<optimized out>, func=<optimized out>)
       at /home/asias/src/cloudius-systems/osv/runtime.cc:156
   #5  0x000000000041743b in file::epoll_del (this=<optimized out>, ep=...) at /home/asias/src/cloudius-systems/osv/fs/vfs/kern_descrip.cc:249
   #6  0x00000000003f7683 in del (key=..., this=0xffff800001746040) at /home/asias/src/cloudius-systems/osv/core/epoll.cc:96
   #7  epoll_ctl (epfd=<optimized out>, op=<optimized out>, fd=<optimized out>, event=0x2000002f9d50) at /home/asias/src/cloudius-systems/osv/core/epoll.cc:283
   #8  0x0000100000c032dc in test_epolloneshot () at /home/asias/src/cloudius-systems/osv/tests/tst-epoll.cc:78
   #9  main (ac=<optimized out>, av=<optimized out>) at /home/asias/src/cloudius-systems/osv/tests/tst-epoll.cc:231
   #10 0x000000000040510b in osv::application::run_main (this=this@entry=0xffffa00001561f18, path="/tests/tst-epoll.so", argc=argc@entry=1,
       argv=argv@entry=0xffffa00002994760) at /home/asias/src/cloudius-systems/osv/core/app.cc:182
   #11 0x0000000000405848 in osv::application::run_main (this=this@entry=0xffffa00001561f18) at /home/asias/src/cloudius-systems/osv/core/app.cc:197
   #12 0x000000000020bbd2 in osv::application::main (this=0xffffa00001561f18) at /home/asias/src/cloudius-systems/osv/core/app.cc:144
   #13 0x0000000000406699 in operator() (__closure=0x0, app=<optimized out>) at /home/asias/src/cloudius-systems/osv/core/app.cc:104
   #14 osv::application::__lambda3::_FUN (app=<optimized out>) at /home/asias/src/cloudius-systems/osv/core/app.cc:106
   #15 0x0000000000433746 in operator() (__closure=0xffffa00003320600) at /home/asias/src/cloudius-systems/osv/libc/pthread.cc:97
   #16 std::_Function_handler<void(), pthread_private::pthread::pthread(void* (*)(void*), void*, sigset_t, const pthread_private::thread_attr*)::__lambda7>::_M_invoke(const std::_Any_data &) (__functor=...) at /home/asias/src/cloudius-systems/osv/external/x64/gcc.bin/usr/include/c++/4.8.2/functional:2071
   #17 0x00000000003e38ab in main (this=0xffff80000354d050) at /home/asias/src/cloudius-systems/osv/core/sched.cc:940
   #18 sched::thread_main_c (t=0xffff80000354d050) at /home/asias/src/cloudius-systems/osv/arch/x64/arch-switch.hh:137
   #19 0x0000000000389c76 in thread_main () at /home/asias/src/cloudius-systems/osv/arch/x64/entry.S:113

Signed-off-by: Asias He <[email protected]>
Signed-off-by: Avi Kivity <[email protected]>
nyh pushed a commit that referenced this issue Dec 9, 2019
New versions of boost like 1.69.0 have more complicated
dependendencies and cause issues with some of the unit tests.

```
tst-rcu-list.so
  libboost_unit_test_framework.so.1.69.0
    libboost_timer.so.1.69.0
      libboost_chrono.so.1.69.0
        libboost_system.so.1.69.0
        libgcc_s.so.1
      libboost_system.so.1.69.0
      libgcc_s.so.1
    libboost_system.so.1.69.0
    libgcc_s.so.1
  libboost_filesystem.so.1.69.0
    libboost_system.so.1.69.0
    libgcc_s.so.1
  libgcc_s.so.1
```

More specifically unit tests like tst-rcu-list and tst-rcu-hashtable
crash when executing FINI functions while unloading boost libraries
with a stack trace like this:

```
#0  0x00000000403a3cf2 in processor::cli_hlt () at arch/x64/processor.hh:247
#1  arch::halt_no_interrupts () at arch/x64/arch.hh:48
#2  osv::halt () at arch/x64/power.cc:26
#3  0x0000000040239dae in abort (fmt=fmt@entry=0x4064155f "Aborted\n") at runtime.cc:132
#4  0x00000000402028ab in abort () at runtime.cc:98
#5  0x000000004021981e in osv::generate_signal (siginfo=..., ef=0xffff80000123c068) at libc/signal.cc:124
#6  0x0000000040463f7f in osv::handle_mmap_fault (addr=<optimized out>, sig=<optimized out>, ef=<optimized out>) at libc/signal.cc:139
#7  0x000000004033da62 in mmu::vm_fault (addr=17592187015168, addr@entry=17592187015648, ef=ef@entry=0xffff80000123c068) at core/mmu.cc:1337
#8  0x000000004039dc30 in page_fault (ef=0xffff80000123c068) at arch/x64/mmu.cc:42
#9  <signal handler called>
#10 0x00001000000ed1e0 in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string() ()
#11 0x000000004023a357 in __cxxabiv1::__cxa_finalize (dso=<optimized out>) at runtime.cc:183
#12 0x000010000041f5f7 in __do_global_dtors_aux ()
#13 0x00002000001008f0 in ?? ()
#14 0x0000000040352f34 in elf::object::run_fini_funcs (this=0xffffa000015d0a00) at core/elf.cc:1105
```

The order in which FINI functions are executed currently follows
the order in which its objects are unloaded. It is not exactly clear why,
but there seems to be some dependency between child
objects in the DT_NEEDED list of paricular object. For example,
if in tst-rcu-list.so the libboost_unit_test_framework.so.1.69.0
is unloaded first and libboost_filesystem.so.1.69.0 unloaded later,
the std string destructor called by libboost_filesystem.so.1.69.0 FINI
function causes page fault shown above.

The commit #4d24b90aa38d90bdcf5ebecf7a5badeca3b657eb from 6 years ago
made process of unloading of objects symmetrical to the loading one
but not quite exactly which seems to be a culprit.

This patch refines the `elf::unload_needed()` method by changing the order
in which the dependent object references are released.

First we release references held by the `_used_by_resolve_plt_got` set
mostly because they are added after DT_NEEDED is processed and `_needed` populated and
we want this to be symmetrical.

Secondly we release references from the `_needed` vector
by iterating and removing elements starting at the end. This
also makes the unloading behavior symmetrical to the order
in which the objects from DT_NEEDED were loaded in first place.

Concluding with this patch all the unit tests now
pass when linked the boost 1.69.0 from Fedora 30 host.

Signed-off-by: Waldemar Kozaczuk <[email protected]>
Message-Id: <[email protected]>
nyh pushed a commit that referenced this issue Mar 29, 2021
…ssembly

This patch adds necessary CFI (Call Frame Information) directives
to the assembly code in entry.S and macros.S to make stack traces
for page faults and interrupt handler look correct. Otherwise
debugging scenarios that involve those becomes very painful.

Before the patch:
-----------------
#0  mmu::file_vma::fault (this=0xffffa00040c9b280, addr=17592186171392, ef=0x200000100110) at core/mmu.cc:1708
#1  0x00000000401da05c in mmu::vm_fault (addr=17592186171392, ef=0x200000100110) at core/mmu.cc:1354
#2  0x000000004020ba9c in page_fault (ef=0x200000100110) at arch/aarch64/mmu.cc:50
#3  0x000000004020b82c in handle_mem_abort () at arch/aarch64/entry.S:161
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

After the patch:
----------------
#0  mmu::file_vma::fault (this=0xffffa00040c9b280, addr=17592186171392, ef=0x200000100110) at core/mmu.cc:1708
#1  0x00000000401da05c in mmu::vm_fault (addr=17592186171392, ef=0x200000100110) at core/mmu.cc:1354
#2  0x000000004020ba9c in page_fault (ef=0x200000100110) at arch/aarch64/mmu.cc:50
#3  <signal handler called>
#4  elf::object::_dynamic_tag (tag=29, this=0xffffa00040dcf800) at core/elf.cc:649
#5  elf::object::dynamic_exists (tag=29, this=0xffffa00040dcf800) at core/elf.cc:641
#6  elf::object::load_needed (this=0xffffa00040dcf800, loaded_objects=std::vector of length 1, capacity 1 = {...}) at core/elf.cc:1068
#7  0x00000000401f1bd4 in elf::program::load_object (this=this@entry=0xffffa00040897ba0, name="/libvdso.so", extra_path=std::vector of length 0, capacity 0,
    loaded_objects=std::vector of length 1, capacity 1 = {...}) at build/downloaded_packages/aarch64/gcc/install/usr/include/c++/10/bits/shared_ptr_base.h:1321
#8  0x00000000401f24fc in elf::program::get_library (this=0xffffa00040897ba0, name="libvdso.so", extra_path=std::vector of length 0, capacity 0, delay_init=false)
    at core/elf.cc:1459
#9  0x0000000040314ea0 in osv::application::prepare_argv (this=this@entry=0xffffa00040dcf610, program=program@entry=0xffffa00040897ba0) at core/app.cc:361
#10 0x0000000040315694 in osv::application::application(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const&, bool, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::function<void ()>) (this=0xffffa00040dcf610, command="/tests/tst-hello.so", args=..., new_program=false, env=0x0, main_function_name="main", post_main=...)
    at core/app.cc:182
...

Before the patch:
-----------------
#0  virtio::blk::ack_irq (this=0xffffa00040a91c00) at drivers/virtio-blk.cc:103
#1  operator() (__closure=0xffffa00040950e40) at drivers/virtio-blk.cc:143
#2  std::__invoke_impl<bool, virtio::blk::blk(virtio::virtio_device&)::<lambda(pci::device&)>::<lambda()>&> (__f=...)
    at build/downloaded_packages/aarch64/gcc/install/usr/include/c++/10/bits/invoke.h:60
#3  std::__invoke_r<bool, virtio::blk::blk(virtio::virtio_device&)::<lambda(pci::device&)>::<lambda()>&> (__fn=...)
    at build/downloaded_packages/aarch64/gcc/install/usr/include/c++/10/bits/invoke.h:141
#4  std::_Function_handler<bool(), virtio::blk::blk(virtio::virtio_device&)::<lambda(pci::device&)>::<lambda()> >::_M_invoke(const std::_Any_data &) (__functor=...)
    at build/downloaded_packages/aarch64/gcc/install/usr/include/c++/10/bits/std_function.h:291
#5  0x000000004020c784 in std::function<bool ()>::operator()() const (this=<optimized out>)
    at build/downloaded_packages/aarch64/gcc/install/usr/include/c++/10/bits/std_function.h:622
#6  interrupt_table::invoke_interrupt (this=this@entry=0x40780968 <idt>, id=id@entry=36) at arch/aarch64/exceptions.cc:135
#7  0x000000004020c95c in interrupt (frame=<optimized out>) at arch/aarch64/exceptions.cc:167
#8  0x000000004020b930 in entry_irq () at arch/aarch64/entry.S:175
#9  0x000000004020b930 in entry_irq () at arch/aarch64/entry.S:175
#10 0x000000004020b930 in entry_irq () at arch/aarch64/entry.S:175
#11 0x000000004020b930 in entry_irq () at arch/aarch64/entry.S:175
#12 0x000000004020b930 in entry_irq () at arch/aarch64/entry.S:175
#13 0x000000004020b930 in entry_irq () at arch/aarch64/entry.S:175
... (infinite number of frames)

After the patch:
----------------
#0  virtio::blk::ack_irq (this=0xffffa00040a91c00) at drivers/virtio-blk.cc:103
#1  operator() (__closure=0xffffa00040950e40) at drivers/virtio-blk.cc:143
#2  std::__invoke_impl<bool, virtio::blk::blk(virtio::virtio_device&)::<lambda(pci::device&)>::<lambda()>&> (__f=...)
    at build/downloaded_packages/aarch64/gcc/install/usr/include/c++/10/bits/invoke.h:60
#3  std::__invoke_r<bool, virtio::blk::blk(virtio::virtio_device&)::<lambda(pci::device&)>::<lambda()>&> (__fn=...)
    at build/downloaded_packages/aarch64/gcc/install/usr/include/c++/10/bits/invoke.h:141
#4  std::_Function_handler<bool(), virtio::blk::blk(virtio::virtio_device&)::<lambda(pci::device&)>::<lambda()> >::_M_invoke(const std::_Any_data &) (__functor=...)
    at build/downloaded_packages/aarch64/gcc/install/usr/include/c++/10/bits/std_function.h:291
#5  0x000000004020c784 in std::function<bool ()>::operator()() const (this=<optimized out>)
    at build/downloaded_packages/aarch64/gcc/install/usr/include/c++/10/bits/std_function.h:622
#6  interrupt_table::invoke_interrupt (this=this@entry=0x40780968 <idt>, id=id@entry=36) at arch/aarch64/exceptions.cc:135
#7  0x000000004020c95c in interrupt (frame=<optimized out>) at arch/aarch64/exceptions.cc:167
#8  <signal handler called>
#9  sched::cpu::do_idle (this=this@entry=0xffff8000407fe040) at core/sched.cc:454
#10 0x00000000402e6b78 in sched::cpu::idle (this=0xffff8000407fe040) at core/sched.cc:472
#11 0x00000000402e6ba0 in operator() (__closure=<optimized out>, __closure=<optimized out>) at core/sched.cc:165
#12 std::__invoke_impl<void, sched::cpu::init_idle_thread()::<lambda()>&> (__f=...)
    at build/downloaded_packages/aarch64/gcc/install/usr/include/c++/10/bits/invoke.h:60
#13 std::__invoke_r<void, sched::cpu::init_idle_thread()::<lambda()>&> (__fn=...) at build/downloaded_packages/aarch64/gcc/install/usr/include/c++/10/bits/invoke.h:153
#14 std::_Function_handler<void(), sched::cpu::init_idle_thread()::<lambda()> >::_M_invoke(const std::_Any_data &) (__functor=...)
    at build/downloaded_packages/aarch64/gcc/install/usr/include/c++/10/bits/std_function.h:291
#15 0x00000000402e72b4 in sched::thread::main (this=0xffffa000408eea48) at core/sched.cc:1267
#16 sched::thread_main_c (t=0xffffa000408eea48) at arch/aarch64/arch-switch.hh:162
#17 0x000000004020b788 in thread_main () at arch/aarch64/entry.S:114

Refs #1128

Signed-off-by: Waldemar Kozaczuk <[email protected]>
Message-Id: <[email protected]>
nyh pushed a commit that referenced this issue May 11, 2022
The manifest skeleton files like usr.manifest.skel have an entry
for libgcc_s_dir looking like this:

/usr/lib/libgcc_s.so.1: %(libgcc_s_dir)s/libgcc_s.so.1

This actually gets expanded quite late during the build process
by upload_manifest.py. The unfortunate consequence of this is that
loader.py used during debugging which reads usr.manifest does not have
any logic to load libgcc_s.so.1. And this makes stack traces
look useless in those cases that involve libgcc_s.so.1.

So this patch slightly changes the scripts/build and scripts/module.py
to expand %(libgcc_s_dir) when writing to build/release/usr.manifest.
As a result of this the stack trace of the crash I have been working
on looks much more reasonable:

(gdb) bt
'#0  0x00000000403047c2 in processor::cli_hlt () at arch/x64/processor.hh:247
#1  arch::halt_no_interrupts () at arch/x64/arch.hh:48
#2  osv::halt () at arch/x64/power.cc:29
#3  0x0000000040239504 in abort (fmt=fmt@entry=0x405b1e93 "Aborted\n") at runtime.cc:142
#4  0x0000000040202e80 in abort () at runtime.cc:106
#5  0x000010000002b6b6 in ?? ()
#6  0x000010000003f5cb in _Unwind_Resume ()
#7  0x0000100000062daa in ?? ()
#8  0x0000100000075b5c in boost::execution_monitor::vexecute(boost::function<void ()> const&) ()
#9  0x000010000007f0a9 in boost::unit_test::framework::init(bool (*)(), int, char**) ()
#10 0x000010000009254d in boost::unit_test::unit_test_main(bool (*)(), int, char**) ()
#11 0x000000004039d021 in osv::application::run_main (this=0xffffa00000bd8c10) at core/app.cc:416
#12 0x000000004039d22d in operator() (app=<optimized out>, __closure=0x0) at core/app.cc:236
#13 _FUN () at core/app.cc:238
#14 0x00000000403d089a in operator() (__closure=0xffffa00000d57800) at libc/pthread.cc:116
#15 std::__invoke_impl<void, pthread_private::pthread::pthread(void* (*)(void*), void*, sigset_t, const pthread_private::thread_attr*)::<lambda()>&> (__f=...) at /usr/include/c++/11/bits/invoke.h:61
#16 std::__invoke_r<void, pthread_private::pthread::pthread(void* (*)(void*), void*, sigset_t, const pthread_private::thread_attr*)::<lambda()>&> (__fn=...) at /usr/include/c++/11/bits/invoke.h:154
#17 std::_Function_handler<void(), pthread_private::pthread::pthread(void* (*)(void*), void*, sigset_t, const pthread_private::thread_attr*)::<lambda()> >::_M_invoke(const std::_Any_data &) (__functor=...) at /usr/include/c++/11/bits/std_function.h:290
#18 0x000000004036b5ae in sched::thread::main (this=0xffff800000f6a040) at core/sched.cc:1267
#19 sched::thread_main_c (t=0xffff800000f6a040) at arch/x64/arch-switch.hh:325
#20 0x00000000402fda43 in thread_main () at arch/x64/entry.S:116

Signed-off-by: Waldemar Kozaczuk <[email protected]>
Message-Id: <[email protected]>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
Projects
None yet
Development

No branches or pull requests

1 participant