On Wed, Aug 1, 2018 at 7:42 PM, Catalin Marinas catalin.marinas@arm.com wrote:
On Mon, Jul 16, 2018 at 01:25:59PM +0200, Andrey Konovalov wrote:
On Thu, Jun 28, 2018 at 9:30 PM, Andrey Konovalov andreyknvl@google.com wrote: So the checker reports ~100 different places where a __user pointer being casted. I've looked through them and found 3 places where we need to add untagging. Source code lines below come from 4.18-rc2+ (6f0d349d).
[...]
I'll add the 3 patches with fixes to v5 of this patchset.
Thanks for investigating. You can fix those three places in your code
OK, will do.
but I was rather looking for a way to check such casting in the future for newly added code. While for the khwasan we can assume it's a debug option, the tagged user pointers are ABI and we need to keep it stable.
We could we actually add some macros for explicit conversion between __user ptr and long and silence the warning there (I guess this would work better for sparse). We can then detect new ptr to long casts as they appear. I just hope that's not too intrusive.
(I haven't tried the sparse patch yet, hopefully sometime this week)
Haven't look at that sparse patch yet myself, but sounds doable. Should these macros go into this patchset or should they go separately? -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html