Re: A question about PROT_NONE on Sparc and Sparc64
Jakub Jelinek <[email protected]>
| Newsgroups | gmane.linux.ports.sparc,gmane.linux.ports.ultrapenguin,gmane.linux.kernel |
|---|---|
| Message-ID | <[email protected]> |
On Wed, Jun 30, 2004 at 04:05:03AM +0100, Jamie Lokier wrote: > I'm doing a survey of the different architectural implementations of > PROT_* flags for mmap() and mprotect(). I'm looking at linux-2.6.5. > > The Sparc and Sparc64 implementations are very similar to plain x86: > read implies exec, exec implies read and write implies read. > > (Aside: A comment in include/asm-sparc/pgtsrmmu.h says that finer-grained > access is possible. Quite a few other architectures do implement > finer-grained access, and even x86 is getting it now, so you may want > to revisit that. The code is already available, and tested, if you > cut that part out of the PaX security patch). I believe R!X and X!R pages ought to be possible on sparc64 too, just use a different bit as "read" in the fast ITLB miss handler from the one fast DTLB miss uses. Jakub - To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html