* Greg KH <greg@xxxxxxxxx> wrote: > What about a simple coccinelle script to test for this type of thing? > We write it once, add it to the in-kernel body of tests, and then 0-day > runs it on all trees all the time. That should catch this type of > issue, like all of the other "bad programming bus" that the tool > currently catches. Yeah, that would work - but today most of our coccinelle scripts are still pretty verbose, and I think it's important to make this a different category of coccinelle script, which is .config driven where a loud warning yells at us. I.e. force the 'zero warnings tolerated' model. I also noticed that Coccinelle builds are pretty slow, so it would still make sense to have a performance oriented static checking facility that does not have the performance baggage of high level functional languages. I.e. either integrate it into Sparse - or start a kernel integrated static analysis tooling project that would only follow control flow initially - which is what we need here I believe. We only have ~115 code blocks in the kernel that set/restore KERNEL_DS, it would be a pity to add a runtime check to every system call ... We could also add a runtime check to oops handling to make sure we don't leak KERNEL_DS through kernel crashes, to ease worries about CVE-2010-4258. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html