| Message ID | 20191122112621.204798-35-glider@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add KernelMemorySanitizer infrastructure | expand |
On Fri, 22 Nov 2019 at 12:28, <glider@google.com> wrote: > > KMSAN metadata for consequent physical pages may be inconsequent, > therefore accessing such pages together may lead to metadata > corruption. > We disable merging pages in biovec to prevent such corruptions. > > Signed-off-by: Alexander Potapenko <glider@google.com> > To: Alexander Potapenko <glider@google.com> > Cc: Jens Axboe <axboe@kernel.dk> > Cc: Andy Lutomirski <luto@kernel.org> > Cc: Vegard Nossum <vegard.nossum@oracle.com> > Cc: Dmitry Vyukov <dvyukov@google.com> > Cc: Christoph Hellwig <hch@lst.de> > Cc: linux-mm@kvack.org > --- > > Change-Id: Id2f2babaf662ac44675c4f2790f4a80ddc328fa7 > --- > block/blk.h | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/block/blk.h b/block/blk.h > index 47fba9362e60..9ee271a22423 100644 > --- a/block/blk.h > +++ b/block/blk.h > @@ -78,6 +78,13 @@ static inline bool biovec_phys_mergeable(struct request_queue *q, > phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset; > phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset; > > +#ifdef CONFIG_KMSAN Prefer 'if (IS_ENABLED(CONFIG_KMSAN))'. Thanks, -- Marco
On Tue, Dec 3, 2019 at 1:54 PM Marco Elver <elver@google.com> wrote: > > On Fri, 22 Nov 2019 at 12:28, <glider@google.com> wrote: > > > > KMSAN metadata for consequent physical pages may be inconsequent, > > therefore accessing such pages together may lead to metadata > > corruption. > > We disable merging pages in biovec to prevent such corruptions. > > > > Signed-off-by: Alexander Potapenko <glider@google.com> > > To: Alexander Potapenko <glider@google.com> > > Cc: Jens Axboe <axboe@kernel.dk> > > Cc: Andy Lutomirski <luto@kernel.org> > > Cc: Vegard Nossum <vegard.nossum@oracle.com> > > Cc: Dmitry Vyukov <dvyukov@google.com> > > Cc: Christoph Hellwig <hch@lst.de> > > Cc: linux-mm@kvack.org > > --- > > > > Change-Id: Id2f2babaf662ac44675c4f2790f4a80ddc328fa7 > > --- > > block/blk.h | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/block/blk.h b/block/blk.h > > index 47fba9362e60..9ee271a22423 100644 > > --- a/block/blk.h > > +++ b/block/blk.h > > @@ -78,6 +78,13 @@ static inline bool biovec_phys_mergeable(struct request_queue *q, > > phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset; > > phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset; > > > > +#ifdef CONFIG_KMSAN > > Prefer 'if (IS_ENABLED(CONFIG_KMSAN))'. WBD in v4. > Thanks, > -- Marco
diff --git a/block/blk.h b/block/blk.h index 47fba9362e60..9ee271a22423 100644 --- a/block/blk.h +++ b/block/blk.h @@ -78,6 +78,13 @@ static inline bool biovec_phys_mergeable(struct request_queue *q, phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset; phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset; +#ifdef CONFIG_KMSAN + /* + * Merging consequent physical pages may not work correctly under KMSAN + * if their metadata pages aren't consequent. Just disable merging. + */ + return false; +#endif if (addr1 + vec1->bv_len != addr2) return false; if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
KMSAN metadata for consequent physical pages may be inconsequent, therefore accessing such pages together may lead to metadata corruption. We disable merging pages in biovec to prevent such corruptions. Signed-off-by: Alexander Potapenko <glider@google.com> To: Alexander Potapenko <glider@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Christoph Hellwig <hch@lst.de> Cc: linux-mm@kvack.org --- Change-Id: Id2f2babaf662ac44675c4f2790f4a80ddc328fa7 --- block/blk.h | 7 +++++++ 1 file changed, 7 insertions(+)