zmq 4.2.1 crashes with SIGBUS under 64-bit SunOS Sparc

[zmqsubmitter]

SunOS 5.11 11.2 sun4v sparc
Sun C++ 5.13 SunOS_sparc

64-bit zmq build crashes with the following stack:

t@14 (l@14) terminated by signal BUS (invalid address alignment)
Current function is zmq::msg_t::init_external_storage
  139       u.zclmsg.content->size = size_;
(dbx) where -l
current thread: t@14
=>[1] libzmq.so.5.1.1:zmq::msg_t::init_external_storage(this = 0x10064ace8, content_ = 0x10064dc54, data_ = 0x10064bc56, size_ = 41U, ffn_ = 0xffffffff677bf6c0                         = &zmq::shared_message_memory_allocator::call_dec_ref(void*,void*), hint_ = 0x10064bc50), line 139 in "msg.cpp"
  [2] libzmq.so.5.1.1:zmq::msg_t::init(this = 0x10064ace8, data_ = 0x10064bc56, size_ = 41U, ffn_ = 0xffffffff677bf6c0 = &zmq::shared_message_memory_allocator::                        call_dec_ref(void*,void*), hint = 0x10064bc50, content_ = 0x10064dc54), line 73 in "msg.cpp"
  [3] libzmq.so.5.1.1:zmq::v2_decoder_t::size_ready(this = 0x10064ac70, msg_size = 41U, read_pos = 0x10064bc56 "^EREADY^KSocket-Type"), line 124 in "v2_decoder.                        cpp"
  [4] libzmq.so.5.1.1:zmq::v2_decoder_t::one_byte_size_ready(this = 0x10064ac70, read_from = 0x10064bc56 "^EREADY^KSocket-Type"), line 80 in "v2_decoder.cpp"
  [5] libzmq.so.5.1.1:zmq::decoder_base_t<zmq::v2_decoder_t,zmq::shared_message_memory_allocator>::decode(this = 0x10064aca0, data_ = 0x10064bc54 "^D)^EREADY^KS                        ocket-Type", size_ = 89U, bytes_used_ = 2U), line 147 in "decoder.hpp"
  [6] libzmq.so.5.1.1:zmq::stream_engine_t::in_event(this = 0x100636230), line 344 in "stream_engine.cpp"
  [7] libzmq.so.5.1.1:zmq::poll_t::loop(this = 0x100559410), line 169 in "poll.cpp"
  [8] libzmq.so.5.1.1:zmq::poll_t::worker_routine(arg_ = 0x100559410), line 190 in "poll.cpp"
  [9] libzmq.so.5.1.1:thread_routine(0x1005594c0, 0x0, 0x0, 0xffffffff6778f238, 0x0, 0x1), at 0xffffffff6778f418

The trouble is apparently in decoder_allocators.cpp:45 which returns non-aligned pointer. The possible workaround is the manual expansion of atomic_counter_t to make it of align-friendly size.

Index: src/atomic_counter.hpp
===================================================================
--- src/atomic_counter.hpp      (revision 141922)
+++ src/atomic_counter.hpp      (working copy)
@@ -77,7 +77,7 @@
         typedef uint32_t integer_t;

         inline atomic_counter_t (integer_t value_ = 0) :
-            value (value_)
+            value (value_), align(this)
         {
         }

@@ -212,6 +212,7 @@
         atomic_counter_t (const atomic_counter_t&);
         const atomic_counter_t& operator = (const atomic_counter_t&);
 #endif
+               void *align;
     };

 }

[bluca]

Could you please fix a bit the formatting of the backtrace and the diff? I'm afraid they are not very readable as is

[zmqsubmitter]

have made a try...

[bluca]

Thanks, that is much clearer now.
Does that diff fix it for you?

[zmqsubmitter]

Re: [zeromq/libzmq] zmq 4.2.1 crashes with SIGBUS under 64-bit SunOS (zmqsubmitter: message 3 of 3 -last one!-) Sparc (#2588) Hello Luca, Tuesday, June 6, 2017, 1:31:31 AM, you wrote: Thanks, that is much clearer now. Does that diff fix it for you? Of course. That is why I proposed it...

…

--  Best regards

[bluca]

Thanks, sorry I misunderstood.

Would you like to send a PR to implement it?

The fix looks fine to me, it's internal code only and everywhere it checks for the actual size of the type so I don't foresee issues.