On Wed 23-02-22 10:36:55, Mike Kravetz wrote: > On 2/23/22 00:33, Michal Hocko wrote: > > On Tue 22-02-22 13:53:56, Mike Kravetz wrote: > >> On 2/21/22 23:47, Michal Hocko wrote: > >> How about adding this note to the commit message? > >> > >> Note: these routines take a user specified value used as an index ONCE > >> during the boot process. As a result, they can not be used as a general > >> method of exploitation. Code changes are being made to eliminate warnings. > > > > This would help but the question whether the change is worth remains. > > Does this change have any other advantage than silencing the warning? > > > > Silencing the warnings was the primary motivation for the change. If Dan > has a plan to change smatch so that they are silenced for __init functions, > then it would be better to not make the changes to use array_index_nospec. > > While making the changes, I shuffled the code a little and did not immediately > notice that it also 'fixes' an overflow/truncation issue when assigning an > unsigned long to int as addressed in [1]. We should probably make this change > whether or not we use array_index_nospec to silence warnings. > > [1] https://lore.kernel.org/linux-mm/20220209134018.8242-1-liuyuntao10@xxxxxxxxxx/ Yeah, this makes sense to me. -- Michal Hocko SUSE Labs
