On Mon, 8 Jan 2001, Kevin D. Kissell wrote:
> Back in the Ancient Old Days of System V, every architecture
> had an architecture-specific system call entry, the first parameter
> of which expressed what needed to be done. Do we have
> such a thing in Linux? That would be the logical place to
> things like cache flush and the atomic operations that were
> being discussed here a couple of weeks ago.
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.
--
+ Maciej W. Rozycki, Technical University of Gdansk, Poland +
+--------------------------------------------------------------+
+ e-mail: macro@ds2.pg.gda.pl, PGP key available +
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