On Sat, Jan 6, 2018 at 8:29 AM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > On Sat, Jan 6, 2018 at 7:14 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: >> On Sat, Jan 06, 2018 at 12:23:47PM +0000, Alan Cox wrote: >>> On Sat, 6 Jan 2018 10:01:54 +0100 >>> Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: >>> >>> > On Fri, Jan 05, 2018 at 05:11:10PM -0800, Dan Williams wrote: >>> > > Static analysis reports that 'offset' may be a user controlled value >>> > >>> > Can I see the rule that determined that? It does not feel like that is >>> > correct, given the 3+ levels deep that this function gets this value >>> > from... >>> >>> On a current x86 you can execute something upwards of 150 instructions in >>> a speculation window. >> >> Yeah, I agree, it's deep :( >> >> But for this patch, I thought the prior review determined that it was >> not a problem. Was that somehow proven incorrect? > > I kept it in the series to get a re-review with the wider netdev > because I missed the discussion leading up to that 'drop the patch' > decision. Sorry, I should have noted that in the changelog or cover > letter. Is there a microbenchmark that can stress this path. If the cost is negligible why play games with it being "probably ok"? Unless someone can say 100% 'offset' is always bounded to something safe by the time we get here just use nospec_array_ptr().
