Segfault on armv5tel-linux-gnueabi

[Ludovic Courtès]

Hello!

A bisect found that commit f60a7648d5926555c7760364a6fbb7dc0cf60720
(v2.0.0-114-gf60a764) introduced a bug showing up on
armv5tel-linux-gnueabi.

The symptom is that ‘./check-guile threads.test’ segfaults.  The
backtrace I have so far isn’t very talkative:

--8<---------------cut here---------------start------------->8---
Program terminated with signal 11, Segmentation fault.
#0  0x4050f82c in siglongjmp () from 
/nix/store/x7n64n36xpqbsi10lgpr3x9f1z9jsp83-glibc-2.12.2/lib/libc.so.6
(gdb) thread apply all bt

Thread 4 (Thread 18394):
#0  0x405ad7b8 in clone () from 
/nix/store/x7n64n36xpqbsi10lgpr3x9f1z9jsp83-glibc-2.12.2/lib/libc.so.6
#1  0x40135fe0 in T.337 () from 
/nix/store/x7n64n36xpqbsi10lgpr3x9f1z9jsp83-glibc-2.12.2/lib/libpthread.so.0
#2  0x00000000 in ?? ()

Thread 3 (Thread 18314):
#0  0x4013e0a8 in sem_wait@@GLIBC_2.4 () from 
/nix/store/x7n64n36xpqbsi10lgpr3x9f1z9jsp83-glibc-2.12.2/lib/libpthread.so.0
#1  0x004abacc in ?? ()
#2  0x004abacc in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

Thread 2 (Thread 18339):
#0  0x4013f314 in read () from 
/nix/store/x7n64n36xpqbsi10lgpr3x9f1z9jsp83-glibc-2.12.2/lib/libpthread.so.0
#1  0x4013eba4 in __pthread_enable_asynccancel () from 
/nix/store/x7n64n36xpqbsi10lgpr3x9f1z9jsp83-glibc-2.12.2/lib/libpthread.so.0
#2  0x00000000 in ?? ()

Thread 1 (Thread 18393):
#0  0x4050f82c in siglongjmp () from 
/nix/store/x7n64n36xpqbsi10lgpr3x9f1z9jsp83-glibc-2.12.2/lib/libc.so.6
#1  0x40300fa4 in fport_flush (port=<value optimized out>) at 
../../libguile/fports.c:816
#2  0x447bb9b8 in ?? ()
#3  0x447bb9b8 in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
--8<---------------cut here---------------end--------------->8---

I’ll keep investigating and report back.

Thanks,
Ludo’.