Messages in this thread | | | Date | Wed, 30 Jun 2004 04:28:05 -0400 | From | Jakub Jelinek <> | Subject | Re: A question about PROT_NONE on Sparc and Sparc64 |
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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.
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