Segmentation Fault on Stack Overflow

Segmentation Fault on Stack Overflow

[Russell Harmon]

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Is this a known issue? If not, I'll put more effort into getting a stack
trace.

% zsh --version
zsh 5.0.2 (x86_64-apple-darwin13.0)
% function inf() { inf }; inf
zsh: correct 'inf' to 'info' [nyae]? n
zsh: correct 'inf' to 'info' [nyae]? n
[1]    11650 segmentation fault  zsh

Re: Segmentation Fault on Stack Overflow

[Frank Terbeck]

Russell Harmon wrote:
> Is this a known issue? If not, I'll put more effort into getting a stack
> trace.
>
> % zsh --version
> zsh 5.0.2 (x86_64-apple-darwin13.0)
> % function inf() { inf }; inf
> zsh: correct 'inf' to 'info' [nyae]? n
> zsh: correct 'inf' to 'info' [nyae]? n
> [1]    11650 segmentation fault  zsh

This is caused by infinite recursion. More recent versions of the shell
will react more reasonably:

zsh% function inf() { inf }; inf
inf: maximum nested function level reached

Regards, Frank

Re: Segmentation Fault on Stack Overflow

[Lawrence Velázquez]

On Jan 3, 2014, at 6:36 PM, Frank Terbeck <ft@bewatermyfriend.org> wrote:

> This is caused by infinite recursion. More recent versions of the shell
> will react more reasonably:
> 
> zsh% function inf() { inf }; inf
> inf: maximum nested function level reached

What version are you using? I'm seeing the segfault with the latest release.

    % zsh --version
    zsh 5.0.4 (x86_64-apple-darwin13.0.2)
    % zsh -c 'function inf() { inf }; inf'
    zsh: segmentation fault  zsh -c 'function inf() { inf }; inf'
    %

vq

Re: Segmentation Fault on Stack Overflow

[Frank Terbeck]

Lawrence Velázquez wrote:
> On Jan 3, 2014, at 6:36 PM, Frank Terbeck <ft@bewatermyfriend.org> wrote:
>> This is caused by infinite recursion. More recent versions of the shell
>> will react more reasonably:
>> 
>> zsh% function inf() { inf }; inf
>> inf: maximum nested function level reached
>
> What version are you using? I'm seeing the segfault with the latest release.
>
>     % zsh --version
>     zsh 5.0.4 (x86_64-apple-darwin13.0.2)
>     % zsh -c 'function inf() { inf }; inf'
>     zsh: segmentation fault  zsh -c 'function inf() { inf }; inf'
>     %

Huh. I must be remembering something incorrectly. The limit was in place
since sometime in 2000¹. But you might be building with the
‘--disable-max-function-depth’ configuration option.

Otherwise the limit should be in place (it defaults to 1000). If the
limit is in place, and the shell still crashes, it might be another
issue, which I couldn't reproduce then.

Regards, Frank

For the record, I've tried this with an older development version of
zsh: zsh-5.0.2-174-g8a70a98

¹ http://www.zsh.org/mla/workers/2000/msg01390.html

Re: Segmentation Fault on Stack Overflow

[Peter Stephenson]

On Sat, 04 Jan 2014 02:46:55 +0100
Frank Terbeck <ft@bewatermyfriend.org> wrote:
> >> zsh% function inf() { inf }; inf
> >> inf: maximum nested function level reached
> 
> Huh. I must be remembering something incorrectly. The limit was in place
> since sometime in 2000¹. But you might be building with the
> ‘--disable-max-function-depth’ configuration option.
> 
> Otherwise the limit should be in place (it defaults to 1000). If the
> limit is in place, and the shell still crashes, it might be another
> issue, which I couldn't reproduce then.

The function depth limit is only a guess at the point where problems
might occur.  It depends on the local environment, both the physical
configuration and the per-process limits, whether this is good enough.

It might be possible to do a little better by querying some of the
memory-related limits (I would guess available stack space is the key
one, but some investigation will be necessary) to see if one of the
limits is getting short and aborting function calls in a handlable
fashion at that level.  Unhelpfully, limits (from getrlimit()) and
current usage (from getrusage()) don't seem to map cleanly onto one
another, and this is all rather system-specific, so this doesn't look
like a trivial project.

pws