call to ffi_call fails even though arguments look right - c

Question

Consider this gist. I have checked and double checked this piece of code for defects and can't find any apparent flaws in the code. It also compiles fine when I use g++ -g -std=c++11 -Wall dynlibtest.cc -ldl -lffi -lstdc++ -odynlibtest && ./dynlibtest (the -ldl and -lffi switches are for the dynamic loading and FFI libraries, respectively).
However, when the highlighted line (l.96) executes it segfaults.
I have also tried pulling it through gdb, and after installing the libc debugging symbols it spits this message out when the ./dynlibtest bin segfaults:
(gdb) next
Program received signal SIGSEGV, Segmentation fault.
__memcpy_sse2_unaligned () at ../sysdeps/x86_64/multiarch/memcpy-sse2-unaligned.S:157
157 ../sysdeps/x86_64/multiarch/memcpy-sse2-unaligned.S: No such file or directory.
Who can help me understand why this segfaults? Is it a bug of some kind or am I using one of the API's wrong?
For reference: the first part of the code calls gettimeofday directly to show that the code can indeed find it, and that even the args are correct when it is called directly.
EDIT: I have added the gdb output when the code segfaults with the output of bt also attached:
$ gdb ./dynlibtest
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Reading symbols from ./dynlibtest...done.
(gdb) break 96
Breakpoint 1 at 0x401032: file dynlibtest.cc, line 96.
(gdb) run
Starting program: /home/j/dev/elisp-ffi/dynlibtest
Test started...
Got main program handle
pre-alloc: tv.tv_sec = 140737340592552
Sleeping for 1 second
post-alloc: tv.tv_sec = 1432058412
Sleeping for 1 second
Fn ptr call: tv.tv_sec = 1432058413
FFI CIF preparation is OK
Sleeping for 1 second
Breakpoint 1, main () at dynlibtest.cc:96
96 ffi_call(&cif, FFI_FN(gettimeofday), &result, args);
(gdb) next
Program received signal SIGSEGV, Segmentation fault.
__memcpy_sse2_unaligned () at ../sysdeps/x86_64/multiarch/memcpy-sse2-unaligned.S:157
157 ../sysdeps/x86_64/multiarch/memcpy-sse2-unaligned.S: No such file or directory.
(gdb) bt
#0 __memcpy_sse2_unaligned () at ../sysdeps/x86_64/multiarch/memcpy-sse2-unaligned.S:157
#1 0x00007ffff79d34c2 in memcpy (__len=8, __src=0x0, __dest=0x7fffffffda48) at /usr/include/x86_64-linux-gnu/bits/string3.h:51
#2 ffi_call (cif=0x7fffffffdca0, fn=0x400ab0 , rvalue=0x7fffffffdc40, avalue=0x7fffffffdc00) at ../src/x86/ffi64.c:504
#3 0x000000000040104e in main () at dynlibtest.cc:96
(gdb)