On Thu, 18 May 2023 12:07:27 +0100 Ryan Roberts <ryan.roberts@xxxxxxx> wrote: > Convert all instances of direct pte_t* dereferencing to instead use > ptep_deref() helper. By default, the helper does a direct dereference as > before, but it can (and will) be overridden by the architecture to fully > encapsulate the contents of the pte. Arch code is deliberately not > converted, as the arch code knows best. > > Conversion was done using Coccinelle: > > ---- > > // $ make coccicheck \ > // COCCI=ptepderef.cocci \ > // SPFLAGS="--include-headers" \ > // MODE=patch > > virtual patch > > @ depends on patch @ > pte_t *v; > @@ > > - *v > + ptep_deref(v) > > ---- > > Then reviewed and hand-edited to avoid multiple unnecessary calls to > ptep_deref(), instead opting to store the result of a single in a > variable, where it is correct to do so. This will benefit arch-overrides > that may be more complex than a simple (optimizable) pointer > dereference. > > Included is a fix for an issue in an earlier version of this patch that > was pointed out by kernel test robot. The issue arose because config > MMU=n elides definition of the ptep helper functions, including > ptep_deref(). HUGETLB_PAGE=n configs still define a simple > huge_ptep_clear_flush() for linking purposes, which dereferences the > ptep. So when both configs are disabled, this caused a build error > because ptep_deref() is not defined. Fix by continuing to do a direct > dereference when MMU=n. This is safe because for this config the arch > code cannot be trying to virtualize the ptes because none of the ptep > helpers are defined. > > Reported-by: kernel test robot <lkp@xxxxxxxxx> > Link: https://lore.kernel.org/oe-kbuild-all/202305120142.yXsNEo6H-lkp@xxxxxxxxx/ > Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx> [...] > mm/damon/ops-common.c | 2 +- > mm/damon/paddr.c | 2 +- > mm/damon/vaddr.c | 10 +- For above mm/damon/ part, Reviewed-by: SeongJae Park <sj@xxxxxxxxxx> Thanks, SJ
