Re: User applications

[Ralf Baechle <ralf@oss.sgi.com>]

On Mon, Jan 08, 2001 at 04:07:31PM +0100, Maciej W. Rozycki wrote:

>  The only case caches need to be synchronized is modifying some code.  The
> ptrace syscall does it automatically for text writes -- it's needed and
> used by gdb to set breakpoints, for example.  For other code there is
> cacheflush() which allows you to flush a cache range relevant to a given
> virtual address (I see it's not implemented very well at the moment).
> 
>  Obviously, you don't want to allow unprivileged users to flush caches as
> a whole as it could lead to a DoS. 

You obviously want to allow partial cache flushes or trampolines don't work
and flushing the entire cache can be constructed from that.

  Ralf