On Tue, Dec 3, 2019 at 3:22 PM Marco Elver <elver@xxxxxxxxxx> wrote: > > On Fri, 22 Nov 2019 at 12:28, <glider@xxxxxxxxxx> wrote: > > > > KMSAN doesn't allow treating adjacent memory pages as such, if they were > > allocated by different alloc_pages() calls. > > ext4_mpage_readpages() however does so: adjacent pages end up being passed > > together to dma_direct_map_sg(). > > To prevent this, jump directly to the buffer_head-based read function in > > KMSAN builds. > > > > Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> > > Cc: "Theodore Ts'o" <tytso@xxxxxxx> > > Cc: Andreas Dilger <adilger.kernel@xxxxxxxxx> > > Cc: Vegard Nossum <vegard.nossum@xxxxxxxxxx> > > Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> > > Cc: linux-mm@xxxxxxxxx > > --- > > > > Change-Id: I54ae8af536626a988e6398ff18a06c179b0ce034 > > --- > > fs/ext4/readpage.c | 11 +++++++++++ > > 1 file changed, 11 insertions(+) > > > > diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c > > index a30b203fa461..a3bb9e3ce5de 100644 > > --- a/fs/ext4/readpage.c > > +++ b/fs/ext4/readpage.c > > @@ -252,6 +252,17 @@ int ext4_mpage_readpages(struct address_space *mapping, > > if (page_has_buffers(page)) > > goto confused; > > > > +#if defined(CONFIG_KMSAN) > > Prefer 'if (IS_ENABLED(CONFIG_KMSAN))'. Done in v4. > Thanks, > -- Marco -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg
