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Re: svn segfault when using svn+ssh schema

On 16/01/2017 20:07, Sam Edge wrote:
On 09/01/2017 19:07, Sam Edge wrote:
On 09/01/2017 02:04, Eliot Moss wrote:
On 1/8/2017 3:45 PM, David Rothenberger wrote:
On 1/8/2017 6:12 AM, Sam Edge wrote:
I've seen a number of 'svn segfault' threads on the mailing list
but none of them seem to cover this specific failure mode.
(Apologies if
one of them does!)

I'm getting segfaults from svn but only when using ssh as the schema.
The following three commands are all accessing the same server, the
of which has been changed to protect the guilty.

SamEdge@thor ~
$ ssh cmserver.XXXXXX.com
( success ( 2 2 ( ) ( edit-pipeline svndiff1 absent-entries
commit-revprops depth log-revprops atomic-revprops partial-replay
inherited-props ephemeral-txnprops file-revs-reverse ) ) )
SamEdge@thor ~
$ svn ls svn+ssh://cmserver.XXXXXX.com/edl/
Segmentation fault (core dumped)
Assuming this is repeatable behavior, perhaps getting a trace using
strace would reveal some more useful information.

Regards - Eliot Moss

Good idea.

Strangely, on another Windows 7 64-bit machine svn+ssh to the same
server is working fine for me. The most significant differences are that
the 'working' machine is running Windows 7 Pro on an Intel CPU with
Sophos AV and domain accounts whereas the 'failing' machine is Windows 7
Home Premium on an AMD with MS Security Essentials and local accounts.
These differences may or may not be relevant of course.

Anyway, attached are the two strace outputs. Diffing them suggests that
it's segfaulting in the fork() "system" call.

Not quite, this strace has...

--- Process 5436 loaded C:\cygwin64\lib\sasl2_3\cygcrammd5-3.dll at 00000003EA090000
--- Process 5436, exception c0000005 at 00000003EA023780
--- Process 5436 unloaded DLL at 00000003EA090000
  333   52465 [main] svn 5436 seterrno_from_win_error: /home/corinna/src/cygwin/cygwin-2.6.1/cygwin-2.6.1-1.x86_64/src/newlib-cygwin/winsup/cygwin/dlfcn.cc:304 windows error 998
   24   52489 [main] svn 5436 geterrno_from_win_error: windows error 998 == errno 14
   20   52509 [main] svn 5436 dlopen: ret 0x0

and then a bit later

   21   91851 [main] svn 5436 fork: entering
  168   92019 [main] svn 5436 sig_send: sendsig 0x80, pid 5436, signal -72, its_me 1
   19   92038 [main] svn 5436 sig_send: wakeup 0x28C
   24   92062 [main] svn 5436 sig_send: Waiting for pack.wakeup 0x28C
   36   92098 [sig] svn 5436 wait_sig: signalling pack.wakeup 0x28C
   27   92125 [main] svn 5436 sig_send: returning 0x0 from sending signal -72
--- Process 5436, exception c0000005 at 0000000180053D3F

So it looks like perhaps cygcrammd5 is faulting during it's DllMain, and perhaps this leaves things in a state that dll_list::topsort can't handle...

I don't have time in the week to run it in a debug session but I'll try
to do so at the weekend given the advice I've been given here. I will
also do a rebaseall after I've tracked down the

Thanks for the feedback folks. Much appreciated.


Hi again.

I've downloaded the debug symbols for subversion & the Cygwin dll and
run the command in gdb. Output attached. Not really giving me any clues
so far.

You also need the symbols for the DLL loaded at the faulting address.

From previous information I'd guess that is cyrus-sasl-debuginfo.

(you can check this using gdb's 'info shared' command)

I've also run 'rebaseall' on the off chance that it would help - it didn't!

Still open to suggestions if anyone has any "light bulb" notions. :-)

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