On Mon, 2008-05-05 at 17:13 -0700, Stephen Neuendorffer wrote: > I'm somewhat ignorant about what this code is attempting to do, but with > some quick poking around (m68knommu, blackfin) seems to suggest that > other architectures don't do this, while others (v850) have almost > exactly the same code (although they are somewhat smarter and are > careful not to flush the whole cache). > > At the very least, it seems like there is some work in this area needed. flush_cache_sigtramp should just invalidate 8 bytes up from the base address of the trampoline. This is just the region on the process stack where we insert a kind of call-back back. Writing the opcodes goes via the dcache, and so there's a vanishingly small possibility that the CPU will get a false hit on on an icache fetch when the code is executed. That was what Michal's patch had when I scanned it yesterday. It certainly won't/shouldn't be invalidating the entire cache. Cheers, John -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
