$ curl -JO 'https://bugzilla.redhat.com/attachment.cgi?id=1184246'
$ sh std-function-armv7hl.cc
+ g++ -std=c++11 -g -O2 -Wall -Wextra std-function-armv7hl.cc
+ valgrind ./a.out
==21418== Memcheck, a memory error detector
==21418== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==21418== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==21418== Command: ./a.out
==21418== 
==21418== Conditional jump or move depends on uninitialised value(s)
==21418==    at 0x1095C: __invoke_impl<int, int (C::* const&)(), C&> (functional:226)
==21418==    by 0x1095C: __invoke<int (C::* const&)(), C&> (functional:260)
==21418==    by 0x1095C: operator()<C&> (functional:613)
==21418==    by 0x1095C: std::_Function_handler<int (C&), int (C::*)()>::_M_invoke(std::_Any_data const&, C&) (functional:1788)
==21418==    by 0x1078B: operator() (functional:2136)
==21418==    by 0x1078B: run (std-function-armv7hl.cc:25)
==21418==    by 0x1078B: main (std-function-armv7hl.cc:36)
==21418== 
==21418== Use of uninitialised value of size 4
==21418==    at 0x10960: __invoke_impl<int, int (C::* const&)(), C&> (functional:226)
==21418==    by 0x10960: __invoke<int (C::* const&)(), C&> (functional:260)
==21418==    by 0x10960: operator()<C&> (functional:613)
==21418==    by 0x10960: std::_Function_handler<int (C&), int (C::*)()>::_M_invoke(std::_Any_data const&, C&) (functional:1788)
==21418==    by 0x1078B: operator() (functional:2136)
==21418==    by 0x1078B: run (std-function-armv7hl.cc:25)
==21418==    by 0x1078B: main (std-function-armv7hl.cc:36)
==21418== 
==21418== Jump to the invalid address stated on the next line
==21418==    at 0x2: ???
==21418==  Address 0x2 is not stack'd, malloc'd or (recently) free'd
==21418== 
==21418== 
==21418== Process terminating with default action of signal 11 (SIGSEGV)
==21418==  Bad permissions for mapped region at address 0x2
==21418==    at 0x2: ???
==21418== 
==21418== HEAP SUMMARY:
==21418==     in use at exit: 0 bytes in 0 blocks
==21418==   total heap usage: 2 allocs, 2 frees, 24,320 bytes allocated
==21418== 
==21418== All heap blocks were freed -- no leaks are possible
==21418== 
==21418== For counts of detected and suppressed errors, rerun with: -v
==21418== Use --track-origins=yes to see where uninitialised values come from
==21418== ERROR SUMMARY: 3 errors from 3 contexts (suppressed: 0 from 0)
std-function-armv7hl.cc: line 4: 21418 Segmentation fault      (core dumped) valgrind ./a.out <<< 42
+ exit 139

Any progress on this?

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This is probably https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77686 which was fixed upstream in GCC 6.3 and so should be fixed by one of the gcc errata for f24.

Looks good.  I am able to reproduce it with gcc-7.1.1-3.fc26.armv7hl.

Thank you for fixing it!

(In reply to Kamil Dudka from comment #5)
> I am able to reproduce it with gcc-7.1.1-3.fc26.armv7hl.

Sorry, I meant to say that I am _not_ able to reproduce it with gcc-7.1.1-3.fc26.armv7hl.