diff options
Diffstat (limited to 'winsup/doc/highlights.xml')
| -rw-r--r-- | winsup/doc/highlights.xml | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/winsup/doc/highlights.xml b/winsup/doc/highlights.xml index 76eb3fb1c..5de789a8c 100644 --- a/winsup/doc/highlights.xml +++ b/winsup/doc/highlights.xml @@ -245,9 +245,8 @@ support for cloning address space between processes and several features actively undermine a reliable <literal>fork</literal> implementation. Three issues are especially prevalent:</para> -<itemizedlist mark="bullet"> - -<listitem><para>DLL base address collisions. Unlike *nix shared +<para><itemizedlist> +<listitem>DLL base address collisions. Unlike *nix shared libraries, which use "position-independent code", Windows shared libraries assume a fixed base address. Whenever the hard-wired address ranges of two DLLs collide (which occurs quite often), the @@ -260,18 +259,18 @@ statically-linked dlls (dependencies known at compile time) are resolved before <literal>cygwin1.dll</literal> initializes and cannot be fixed afterward. This problem can only be solved by removing the base address conflicts which cause the problem, -usually using the <literal>rebaseall</literal> tool.</para></listitem> +usually using the <literal>rebaseall</literal> tool.</listitem> -<listitem><para>Address space layout randomization (ASLR). Starting with +<listitem>Address space layout randomization (ASLR). Starting with Vista, Windows implements ASLR, which means that thread stacks, heap, memory-mapped files, and statically-linked dlls are placed at different (random) locations in each process. This behaviour interferes with a proper <literal>fork</literal>, and if an unmovable object (process heap or system dll) ends up at the wrong location, Cygwin can do nothing to compensate (though it will -retry a few times automatically).</para></listitem> +retry a few times automatically).</listitem> -<listitem><para>DLL injection by +<listitem>DLL injection by <ulink url="http://cygwin.com/faq/faq.html#faq.using.bloda"> BLODA</ulink>. Badly-behaved applications which inject dlls into other processes often manage to clobber important @@ -280,9 +279,7 @@ collisions which rebasing cannot fix. The only way to resolve this problem is to remove (usually uninstall) the offending app. See <xref linkend="cygwinenv-implemented-options"></xref> for the <literal>detect_bloda</literal> option, which may be able to identify the -BLODA.</para></listitem> - -</itemizedlist> +BLODA.</listitem></itemizedlist></para> <para>In summary, current Windows implementations make it impossible to implement a perfectly reliable fork, and occasional |