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authorDan Williams <dan.j.williams@intel.com>2017-02-28 18:32:48 -0800
committerDan Williams <dan.j.williams@intel.com>2017-03-01 00:49:42 -0800
commit86ef58a4e35e8fa66afb5898cf6dec6a3bb29f67 (patch)
tree95f6525d1319cc5bd7803518a96beb1e227f173a /include/linux
parentdf06a2d57711a1472ced72207373eeb6422d4721 (diff)
nfit, libnvdimm: fix interleave set cookie calculation
The interleave-set cookie is a sum that sanity checks the composition of an interleave set has not changed from when the namespace was initially created. The checksum is calculated by sorting the DIMMs by their location in the interleave-set. The comparison for the sort must be 64-bit wide, not byte-by-byte as performed by memcmp() in the broken case. Fix the implementation to accept correct cookie values in addition to the Linux "memcmp" order cookies, but only allow correct cookies to be generated going forward. It does mean that namespaces created by third-party-tooling, or created by newer kernels with this fix, will not validate on older kernels. However, there are a couple mitigating conditions: 1/ platforms with namespace-label capable NVDIMMs are not widely available. 2/ interleave-sets with a single-dimm are by definition not affected (nothing to sort). This covers the QEMU-KVM NVDIMM emulation case. The cookie stored in the namespace label will be fixed by any write the namespace label, the most straightforward way to achieve this is to write to the "alt_name" attribute of a namespace in sysfs. Cc: <stable@vger.kernel.org> Fixes: eaf961536e16 ("libnvdimm, nfit: add interleave-set state-tracking infrastructure") Reported-by: Nicholas Moulin <nicholas.w.moulin@linux.intel.com> Tested-by: Nicholas Moulin <nicholas.w.moulin@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/libnvdimm.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 8458c5351e56..77e7af32543f 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -70,6 +70,8 @@ struct nd_cmd_desc {
struct nd_interleave_set {
u64 cookie;
+ /* compatibility with initial buggy Linux implementation */
+ u64 altcookie;
};
struct nd_mapping_desc {