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Message-ID: <147931721349.37471.4835899844582504197.stgit@dwillia2-desk3.amr.corp.intel.com>
Date: Wed, 16 Nov 2016 09:26:53 -0800
From: Dan Williams <dan.j.williams@...el.com>
To: linux-nvdimm@...ts.01.org
Cc: linux-mm@...ck.org, Dave Hansen <dave.hansen@...ux.intel.com>,
linux-kernel@...r.kernel.org, stable@...r.kernel.org,
Pawel Lebioda <pawel.lebioda@...el.com>
Subject: [PATCH] device-dax: fail all private mapping attempts
The device-dax implementation originally tried to be tricky and allow
private read-only mappings, but in the process allowed writable
MAP_PRIVATE + MAP_NORESERVE mappings. For simplicity and predictability
just fail all private mapping attempts since device-dax memory is
statically allocated and will never support overcommit.
Cc: <stable@...r.kernel.org>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Fixes: dee410792419 ("/dev/dax, core: file operations and dax-mmap")
Reported-by: Pawel Lebioda <pawel.lebioda@...el.com>
Signed-off-by: Dan Williams <dan.j.williams@...el.com>
---
drivers/dax/dax.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c
index 0e499bfca41c..3d94ff20fdca 100644
--- a/drivers/dax/dax.c
+++ b/drivers/dax/dax.c
@@ -270,8 +270,8 @@ static int check_vma(struct dax_dev *dax_dev, struct vm_area_struct *vma,
if (!dax_dev->alive)
return -ENXIO;
- /* prevent private / writable mappings from being established */
- if ((vma->vm_flags & (VM_NORESERVE|VM_SHARED|VM_WRITE)) == VM_WRITE) {
+ /* prevent private mappings from being established */
+ if ((vma->vm_flags & VM_SHARED) != VM_SHARED) {
dev_info(dev, "%s: %s: fail, attempted private mapping\n",
current->comm, func);
return -EINVAL;
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