fftw-3 @3.3.8 (math): on macOS Catalina (only) segmentation fault for 2^N with N=12

[sa35]

On macOS Catalina 10.15.1 I get a segmentation fault for 2 to power N with N=12. If I am downloading fftw3 source (3.3.8) and compile it myself, this is not the case. Hence I assume something is wrong with the fftw-3 package.

[sa35]

Little example I used to reproduce the seg.fault

[jmroot (Joshua Root)]

How did you configure it when you built it yourself?

[sa35]

I just used the automake tool chain:

configure 
make 
make install

[jmroot (Joshua Root)]

Yes but what configure options and CFLAGS etc did you use? That's going to be the difference between your build and one done with MacPorts.

[sa35]

To compile fftw I just configured it with

--enable-shared

and nothing else.

[volgy (Peter Volgyesi)]

Minimal program demonstrating the crash.

[volgy (Peter Volgyesi)]

I have a similar problem with several packages using fftw-3 or fftw-3-single (3.3.8) on Catalina. I created a minimal program to trigger the crash (Abort trap: 6), see the attached file (fftw_crash.c). The FFTW library corrupts the stack during the planning phase (fftw_plan_dft_1d)

It seems the problem is with the binary distribution, only. Installing the same package from source (port -s install fftw-3) resolves the problem. Here is some information on my system:

$ uname -a
Darwin watney.local 19.2.0 Darwin Kernel Version 19.2.0: Sat Nov  9 03:47:04 PST 2019; root:xnu-6153.61.1~20/RELEASE_X86_64 x86_64

$ xcode-select -p
/Applications/Xcode.app/Contents/Developer

$ /usr/bin/xcodebuild -version
Xcode 11.3
Build version 11C29

[astroboylrx (Rixin Li)]

I've countered this issue, too. I don't know whose bug it is, either fftw-3 or Catalina. But there are reports from other softwares with this issue, e.g., ffmpeg ​https://trac.ffmpeg.org/ticket/8073

If you use LLDB to debug the program you attached (see below), you'll see it's a general protection fault: code=EXC_I386_GPFLT (some explanations here ​https://stackoverflow.com/a/19652167/4009531). And the error is called libdyld.dylib`stack_not_16_byte_aligned_error. The 12th comment ​https://trac.ffmpeg.org/ticket/8073#comment:12 in the ffmpeg bug tracker forum explained a little bit: "Stack checking is on by default on all platforms to prevent memory corruptions. (25859140)". And this post ​https://artempyanykh.com/blog/posts/2019-01-16-assembling-fizz-buzz.html#stack-align also explains a little bit: "When memory is not aligned the processor generates a general protection exception that translates to a segmentation fault."

➜  ~/build $ lldb ./fftw3_test
(lldb) target create "./fftw3_test"
Current executable set to './fftw3_test' (x86_64).
(lldb) run
Process 80432 launched: '/Users/rixin/Downloads/fftw3_bare/build/fftw3_test' (x86_64)
debug> N=4096, offset=0
Process 80432 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=EXC_I386_GPFLT)
    frame #0: 0x00007fff655352be libdyld.dylib`stack_not_16_byte_aligned_error
libdyld.dylib`stack_not_16_byte_aligned_error:
->  0x7fff655352be <+0>: movdqa %xmm0, (%rsp)
    0x7fff655352c3 <+5>: int3
    0x7fff655352c4 <+6>: nop
    0x7fff655352c5 <+7>: nop
Target 0: (fftw3_test) stopped.

Hopefully, my search can contribute more information to the discussions here. Sadly, there is no listed maintainer for this port. I've tried to Google this error but got no luck. Thanks a lot for mentioning that compiling fftw from the source could work. I will try that.

[MarcusCalhoun-Lopez (Marcus Calhoun-Lopez)]

In 86e82cd007b387d3b3762654ce670db810602324/macports-ports (master):

fftw-3: use xcode_workaround PG

Fixes #59678