• Dan Williams's avatar
    device-dax: check devm_nsio_enable() return value · 6a84fb4b
    Dan Williams authored
    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>
    6a84fb4b
pmem.c 4.02 KB