diff options
| -rw-r--r-- | winsup/doc/ChangeLog | 6 | ||||
| -rw-r--r-- | winsup/doc/faq-setup.xml | 4 | ||||
| -rw-r--r-- | winsup/doc/faq-using.xml | 91 |
3 files changed, 101 insertions, 0 deletions
diff --git a/winsup/doc/ChangeLog b/winsup/doc/ChangeLog index bdef739..9559272 100644 --- a/winsup/doc/ChangeLog +++ b/winsup/doc/ChangeLog @@ -1,3 +1,9 @@ +2007-29-12 Dave Korn <dave.korn@artimi.com> + + * faq-using.xml (faq.using.bloda): New entry. + (faq.using.firewall, faq.using.anti-virus): Link to faq.using.bloda. + * faq-setup.xml (faq.setup.hang): Likewise link to faq.using.bloda. + 2007-12-16 Christopher Faylor <me+cygwin@cgf.cx> * pathnames.xml: Fix a typo. diff --git a/winsup/doc/faq-setup.xml b/winsup/doc/faq-setup.xml index 5de59bb..55c2916 100644 --- a/winsup/doc/faq-setup.xml +++ b/winsup/doc/faq-setup.xml @@ -155,6 +155,10 @@ disk if you are paranoid. <para>This should be safe, but only if Cygwin Setup is not substituted by something malicious, and no mirror has been compromised. </para> +<para>See also <ulink url="http://cygwin.com/faq/faq.using.html#faq.using.bloda" /> +for a list of applications that have been known, at one time or another, to +interfere with the normal functioning of Cygwin. +</para> </answer></qandaentry> <qandaentry id="faq.setup.what-packages"> diff --git a/winsup/doc/faq-using.xml b/winsup/doc/faq-using.xml index a766dce..c5676d8 100644 --- a/winsup/doc/faq-using.xml +++ b/winsup/doc/faq-using.xml @@ -633,6 +633,10 @@ of poorly written firewall-type software that causes things to break. Note that with many of these products, simply disabling the firewall does not remove these changes; it must be completely uninstalled. </para> +<para>See also <ulink url="http://cygwin.com/faq/faq.using.html#faq.using.bloda" /> +for a list of applications that have been known, at one time or another, to +interfere with the normal functioning of Cygwin. +</para> </answer></qandaentry> <qandaentry id="faq.using.sharing-files"> @@ -782,6 +786,10 @@ contents are exempt from scanning. In a default installation, this would be <literal>C:\cygwin\bin</literal>. Obviously, this could be exploited by a hostile non-Cygwin program, so do this at your own risk. </para> +<para>See also <ulink url="http://cygwin.com/faq/faq.using.html#faq.using.bloda" /> +for a list of applications that have been known, at one time or another, to +interfere with the normal functioning of Cygwin. +</para> </answer></qandaentry> <qandaentry id="faq.using.emacs"> @@ -950,3 +958,86 @@ means they do not understand Cygwin mounts or symbolic links. elsewhere in this FAQ. </para></answer></qandaentry> +<qandaentry id="faq.using.bloda"> +<question><para>What applications have been found to interfere with Cygwin?</para></question> +<answer> + +<para>From time to time, people have reported strange failures and problems in +Cygwin and Cygwin packages that seem to have no rational explanation. Among +the most common symptoms they report are fork failures, memory leaks, and file +access denied problems. These problems, when they have been traced, often appear +to be caused by interference from other software installed on the same PC. Security +software, in particular, such as anti-virus, anti-spyware, and firewall applications, +often implements its functions by installing hooks into various parts of the system, +including both the Explorer shell and the underlying kernel. Sometimes these hooks +are not implemented in an entirely transparent fashion, and cause changes in the +behaviour which affect the operation of other programs, such as Cygwin. +</para> +<para>Among the software that has been found to cause difficulties are:</para> +<para><itemizedlist> +<listitem><para>Sonic Solutions burning software containing DLA component</para></listitem> +<listitem><para>Norton/MacAffee/Symantec antivirus or antispyware</para></listitem> +<listitem><para>Logitech webcam software with "Logitech process monitor" service</para></listitem> +<listitem><para>Kerio, Agnitum or ZoneAlarm Personal Firewall</para></listitem> +<listitem><para>Iolo System Mechanic/AntiVirus/Firewall</para></listitem> +<listitem><para>LanDesk</para></listitem> +<listitem><para>Windows Defender </para></listitem> +<listitem><para>Embassy Trust Suite fingerprint reader software wxvault.dll</para></listitem> +<listitem><para>NOD32 Antivirus</para></listitem> +<listitem><para>ByteMobile laptop optimization client</para></listitem> +</itemizedlist></para> +<para>Sometimes these problems can be worked around, by temporarily or partially +disabling the offending software. For instance, it may be possible to disable +on-access scanning in your antivirus, or configure it to ignore files under the +Cygwin installation root. Often, unfortunately, this is not possible; even disabling +the software may not work, since many applications that hook the operating system +leave their hooks installed when disabled, and simply set them into what is intended +to be a completely transparent pass-through mode. Sometimes this pass-through is not +as transparent as all that, and the hooks still interfere with Cygwin; in these cases, +it may be necessary to uninstall the software altogether to restore normal operation. +</para> +<para>Some of the symptoms you may experience are:</para> +<para><itemizedlist> +<listitem> +<para>Random fork() failures.</para> +<para>Caused by hook DLLs that load themselves into every process in the +system. POSIX fork() semantics require that the memory map of the child process +must be an exact duplicate of the parent process' layout. If one of these DLLs +loads itself at a different base address in the child's memory space as compared +to the address it was loaded at in the parent, it can end up taking the space that +belonged to a different DLL in the parent. When Cygwin can't load the original +DLL at that same address in the child, the fork() call has to fail. +</para> +</listitem> +<listitem> +<para>File access problems.</para> +<para>Some programs (e.g., virus scanners with on-access scanning) scan or +otherwise operate on every file accessed by all the other software running on +your computer. In some cases they may retain an open handle on the file even +after the software that is really using the file has closed it. This has been +known to cause operations such as deletes, renames and moves to fail with +access denied errors. In extreme cases it has been known for scanners to leak +file handles, leading to kernel memory starvation. +</para> +</listitem> +<listitem> +<para>Networking issues</para> +<para>Firewall software sometimes gets a bit funny about Cygwin. It's not +currently understood why; Cygwin only uses the standard Winsock2 API, but +perhaps in some less-commonly used fashion that doesn't get as well tested +by the publishers of firewalls. Symptoms include mysterious failures to +connect, or corruption of network data being sent or received.</para> +</listitem> +<listitem> +<para>Memory and/or handle leaks</para> +<para>Some applications that hook into the Windows operating system exhibit +bugs when interacting with Cygwin that cause them to leak allocated memory +or other system resources. Symptoms include complaints about out-of-memory +errors and even virtual memory exhaustion dialog boxes from the O/S; it is +often possible to see the excess memory allocation using a tool such as +Task Manager or Sysinternals' Process Explorer, although interpreting the +statistics they present is not always straightforward owing to complications +such as virtual memory paging and file caching.</para> +</listitem> +</itemizedlist></para> +</answer></qandaentry> |