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))'. Thanks, -- Marco
