This is the mail archive of the
cygwin
mailing list for the Cygwin project.
Re: [1.7] deleting in-use directories
On Apr 9 17:30, Eric Blake wrote:
> Corinna Vinschen <corinna-cygwin <at> cygwin.com> writes:
>
> > Incredible but true. It was an alignment problem with a local buffer
> > in the function which moves the directory to the bin when a sharing
> > violation occurs.
>
> > BYTE infobuf[sizeof (FILE_NAME_INFORMATION) + 32767 * sizeof (WCHAR)]
>
> That's an awfully big buffer to be stack-allocating. It's bigger than a system
> page, which means if you are nearing stack overflow, then call rmdir(), your
> application could suffer from silent termination rather than orderly SIGSEGV
> stack overflow when it accesses beyond the guard page.
Yes, I know. I didn't use the TLS temporary path buffer because the
returned size is potentially a bit bigger than 64K (by the above sizeof
(FILE_NAME_INFORMATION)), which is the max. buffer size for these temp
buffers. I was already wondering when I fixed the alignment problem
if we should just ignore this potential problem.
Erm...
Actually the max size is 64K + 4 bytes. Given that PATH_MAX is 4096,
maybe a temporary TLS buffer of 64K is sensible enough.
Hang on, I'll fix that in a minute.
Corinna
--
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Project Co-Leader cygwin AT cygwin DOT com
Red Hat
--
Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Problem reports: http://cygwin.com/problems.html
Documentation: http://cygwin.com/docs.html
FAQ: http://cygwin.com/faq/