The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 08bb558ac11ab944e0539e78619d7b4c356278bd Mon Sep 17 00:00:00 2001
From: Jack Morgenstein jackm@dev.mellanox.co.il Date: Wed, 23 May 2018 15:30:30 +0300 Subject: [PATCH] IB/core: Make testing MR flags for writability a static inline function
Make the MR writability flags check, which is performed in umem.c, a static inline function in file ib_verbs.h
This allows the function to be used by low-level infiniband drivers.
Cc: stable@vger.kernel.org Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Jack Morgenstein jackm@dev.mellanox.co.il Signed-off-by: Leon Romanovsky leonro@mellanox.com
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 2b6c9b516070..d76455edd292 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -119,16 +119,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, umem->length = size; umem->address = addr; umem->page_shift = PAGE_SHIFT; - /* - * We ask for writable memory if any of the following - * access flags are set. "Local write" and "remote write" - * obviously require write access. "Remote atomic" can do - * things like fetch and add, which will modify memory, and - * "MW bind" can change permissions by binding a window. - */ - umem->writable = !!(access & - (IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE | - IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND)); + umem->writable = ib_access_writable(access);
if (access & IB_ACCESS_ON_DEMAND) { ret = ib_umem_odp_get(context, umem, access); diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index 9fc8a825aa28..20fa5c591e81 100644 --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -3734,6 +3734,20 @@ static inline int ib_check_mr_access(int flags) return 0; }
+static inline bool ib_access_writable(int access_flags) +{ + /* + * We have writable memory backing the MR if any of the following + * access flags are set. "Local write" and "remote write" obviously + * require write access. "Remote atomic" can do things like fetch and + * add, which will modify memory, and "MW bind" can change permissions + * by binding a window. + */ + return access_flags & + (IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE | + IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND); +} + /** * ib_check_mr_status: lightweight check of MR status. * This routine may provide status checks on a selected
Hi Greg,
On Sun, Jul 01, 2018 at 11:37:25AM +0200, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
The attached backported patch should apply to 4.4-stable and also to 4.9-stable.
Though I am confused about why this should be in stable, unless some later fix, required in stable, depends on this.
-- Regards Sudip
On Sun, Aug 12, 2018 at 02:56:49PM +0100, Sudip Mukherjee wrote:
Hi Greg,
On Sun, Jul 01, 2018 at 11:37:25AM +0200, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
The attached backported patch should apply to 4.4-stable and also to 4.9-stable.
Though I am confused about why this should be in stable, unless some later fix, required in stable, depends on this.
That's a good question. Can some IB developer please answer this before I queue this up?
thanks,
greg k-h
On Sun, Aug 12, 2018 at 05:28:10PM +0200, Greg KH wrote:
On Sun, Aug 12, 2018 at 02:56:49PM +0100, Sudip Mukherjee wrote:
Hi Greg,
On Sun, Jul 01, 2018 at 11:37:25AM +0200, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
The attached backported patch should apply to 4.4-stable and also to 4.9-stable.
Though I am confused about why this should be in stable, unless some later fix, required in stable, depends on this.
That's a good question. Can some IB developer please answer this before I queue this up?
It is required for this upstream patch:
commit d8f9cc328c8888369880e2527e9186d745f2bbf6 Author: Jack Morgenstein jackm@dev.mellanox.co.il Date: Wed May 23 15:30:31 2018 +0300
IB/mlx4: Mark user MR as writable if actual virtual memory is writable
To allow rereg_user_mr to modify the MR from read-only to writable without using get_user_pages again, we needed to define the initial MR as writable. However, this was originally done unconditionally, without taking into account the writability of the underlying virtual memory.
As a result, any attempt to register a read-only MR over read-only virtual memory failed.
To fix this, do not add the writable flag bit when the user virtual memory is not writable (e.g. const memory).
However, when the underlying memory is NOT writable (and we therefore do not define the initial MR as writable), the IB core adds a "force writable" flag to its user-pages request. If this succeeds, the reg_user_mr caller gets a writable copy of the original pages.
If the user-space caller then does a rereg_user_mr operation to enable writability, this will succeed. This should not be allowed, since the original virtual memory was not writable.
Cc: stable@vger.kernel.org Fixes: 9376932d0c26 ("IB/mlx4_ib: Add support for user MR re-registration") Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Jack Morgenstein jackm@dev.mellanox.co.il Signed-off-by: Leon Romanovsky leonro@mellanox.com
On Sun, Aug 12, 2018 at 11:06:07AM -0600, Jason Gunthorpe wrote:
On Sun, Aug 12, 2018 at 05:28:10PM +0200, Greg KH wrote:
On Sun, Aug 12, 2018 at 02:56:49PM +0100, Sudip Mukherjee wrote:
Hi Greg,
On Sun, Jul 01, 2018 at 11:37:25AM +0200, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
The attached backported patch should apply to 4.4-stable and also to 4.9-stable.
Though I am confused about why this should be in stable, unless some later fix, required in stable, depends on this.
That's a good question. Can some IB developer please answer this before I queue this up?
It is required for this upstream patch:
commit d8f9cc328c8888369880e2527e9186d745f2bbf6 Author: Jack Morgenstein jackm@dev.mellanox.co.il Date: Wed May 23 15:30:31 2018 +0300
Thanks Jason. Looks like d8f9cc328c88 ("IB/mlx4: Mark user MR as writable if actual virtual memory is writable") will be needed in both 4.4-stable and 4.9-stable, but will need backporting.
-- Regards Sudip
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