This is a note to let you know that I've just added the patch titled
infiniband: Fix alignment of mmap cookies to support VIPT caching
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: infiniband-fix-alignment-of-mmap-cookies-to-support-vipt-caching.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Thu Dec 21 09:02:40 CET 2017
From: Jason Gunthorpe jgunthorpe@obsidianresearch.com Date: Fri, 10 Mar 2017 11:34:20 -0700 Subject: infiniband: Fix alignment of mmap cookies to support VIPT caching
From: Jason Gunthorpe jgunthorpe@obsidianresearch.com
[ Upstream commit cb8864559631754ac93d5734b165ccd0cad4728c ]
When vmalloc_user is used to create memory that is supposed to be mmap'd to user space, it is necessary for the mmap cookie (eg the offset) to be aligned to SHMLBA.
This creates a situation where all virtual mappings of the same physical page share the same virtual cache index and guarantees VIPT coherence. Otherwise the cache is non-coherent and the kernel will not see writes by userspace when reading the shared page (or vice-versa).
Reported-by: Josh Beavers josh.beavers@gmail.com Signed-off-by: Jason Gunthorpe jgunthorpe@obsidianresearch.com Signed-off-by: Doug Ledford dledford@redhat.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/infiniband/sw/rdmavt/mmap.c | 4 ++-- drivers/infiniband/sw/rxe/rxe_mmap.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/infiniband/sw/rdmavt/mmap.c +++ b/drivers/infiniband/sw/rdmavt/mmap.c @@ -170,9 +170,9 @@ struct rvt_mmap_info *rvt_create_mmap_in
spin_lock_irq(&rdi->mmap_offset_lock); if (rdi->mmap_offset == 0) - rdi->mmap_offset = PAGE_SIZE; + rdi->mmap_offset = ALIGN(PAGE_SIZE, SHMLBA); ip->offset = rdi->mmap_offset; - rdi->mmap_offset += size; + rdi->mmap_offset += ALIGN(size, SHMLBA); spin_unlock_irq(&rdi->mmap_offset_lock);
INIT_LIST_HEAD(&ip->pending_mmaps); --- a/drivers/infiniband/sw/rxe/rxe_mmap.c +++ b/drivers/infiniband/sw/rxe/rxe_mmap.c @@ -156,10 +156,10 @@ struct rxe_mmap_info *rxe_create_mmap_in spin_lock_bh(&rxe->mmap_offset_lock);
if (rxe->mmap_offset == 0) - rxe->mmap_offset = PAGE_SIZE; + rxe->mmap_offset = ALIGN(PAGE_SIZE, SHMLBA);
ip->info.offset = rxe->mmap_offset; - rxe->mmap_offset += size; + rxe->mmap_offset += ALIGN(size, SHMLBA);
spin_unlock_bh(&rxe->mmap_offset_lock);
Patches currently in stable-queue which might be from jgunthorpe@obsidianresearch.com are
queue-4.9/infiniband-fix-alignment-of-mmap-cookies-to-support-vipt-caching.patch