On Fri, 23 Oct 2020 at 22:03, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > On Fri, Oct 23, 2020 at 8:54 AM Linus Torvalds > <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > On Fri, Oct 23, 2020 at 12:14 AM Rasmus Villemoes > > <linux@xxxxxxxxxxxxxxxxxx> wrote: > > > > > > That's certainly garbage. Now, I don't know if it's a sufficient fix (or > > > could break something else), but the obvious first step of rearranging > > > so that the ptr argument is evaluated before the assignment to __val_pu > > > > Ack. We could do that. > > > > I'm more inclined to just bite the bullet and go back to the ugly > > conditional on the size that I had hoped to avoid, but if that turns > > out too ugly, mind signing off on your patch and I'll have that as a > > fallback? > > Actually, looking at that code, and the fact that we've used the > "register asm()" format forever for the get_user() side, I think your > approach is the right one. > > I'd rename the internal ptr variable to "__ptr_pu", and make sure the > assignments happen just before the asm call (with the __val_pu > assignment being the final thing). > > lso, it needs to be > > void __user *__ptr_pu; > > instead of > > __typeof__(ptr) __ptr = (ptr); > > because "ptr" may actually be an array, and we need to have the usual > C "array to pointer" conversions happen, rather than try to make > __ptr_pu be an array too. > > So the patch would become something like the appended instead, but I'd > still like your sign-off (and I'd put you as author of the fix). > > Narest, can you confirm that this patch fixes the issue for you? This patch fixed the reported problem. Tested-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> Build location: https://builds.tuxbuild.com/uDAiW8jkN61oWoyxZDkEYA/ Test logs, https://lkft.validation.linaro.org/scheduler/job/1868045#L1597 - Naresh
