Skip to content
Commit 6a84fb4b authored by Dan Williams's avatar Dan Williams
Browse files

device-dax: check devm_nsio_enable() return value



If the dax_pmem driver is passed a resource that is already busy the
driver probe attempt should fail with a message like the following:

  dax_pmem dax0.1: could not reserve region [mem 0x100000000-0x11fffffff]

However, if we do not catch the error we crash for the obvious reason of
accessing memory that is not mapped.

 BUG: unable to handle kernel paging request at ffffc90020001000
 IP: [<ffffffff81496712>] __memcpy+0x12/0x20
 [..]
 Call Trace:
  [<ffffffff815c4960>] ? nsio_rw_bytes+0x60/0x180
  [<ffffffff815c6045>] nd_pfn_validate+0x75/0x320
  [<ffffffff815c63a9>] nvdimm_setup_pfn+0xb9/0x5d0
  [<ffffffff815c48ef>] ? devm_nsio_enable+0xff/0x110
  [<ffffffff815cb699>] dax_pmem_probe+0x59/0x260

Cc: <stable@vger.kernel.org>
Fixes: ab68f262 ("/dev/dax, pmem: direct access to persistent memory")
Reported-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent ed99d367
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment