On Sun, Feb 09, 2025 at 05:47:11PM +0000, David Laight wrote: > Historiaclly the code relied on access_ok() to validate the address range. > Commit 26f4c328079d7 added an explicit wrap check before access_ok(). > Commit c28b1fc70390d then changed the wrap test to use check_add_overflow(). > Commit 6014bc27561f2 relaxed the checks in x86-64's access_ok() and added > an explicit check for TASK_SIZE here to make up for it. > That left a pointless access_ok() call with its associated 'lfence' that > can never actually fail. > So just delete the test. > > Signed-off-by: David Laight <david.laight.linux@xxxxxxxxx> > --- > mm/gup.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> I often wonder about about access_ok() calls, if they still do anything.. Jason
