queue-4.4/intel_th-gth-fix-an-off-by-one-in-output-unassigning.patch

   1 From 91d3f8a629849968dc91d6ce54f2d46abf4feb7f Mon Sep 17 00:00:00 2001
   2 From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
   3 Date: Fri, 1 Mar 2019 10:09:55 +0200
   4 Subject: intel_th: gth: Fix an off-by-one in output unassigning
   5
   6 From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
   7
   8 commit 91d3f8a629849968dc91d6ce54f2d46abf4feb7f upstream.
   9
  10 Commit 9ed3f22223c3 ("intel_th: Don't reference unassigned outputs")
  11 fixes a NULL dereference for all masters except the last one ("256+"),
  12 which keeps the stale pointer after the output driver had been unassigned.
  13
  14 Fix the off-by-one.
  15
  16 Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
  17 Fixes: 9ed3f22223c3 ("intel_th: Don't reference unassigned outputs")
  18 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  19
  20 ---
  21  drivers/hwtracing/intel_th/gth.c |    2 +-
  22  1 file changed, 1 insertion(+), 1 deletion(-)
  23
  24 --- a/drivers/hwtracing/intel_th/gth.c
  25 +++ b/drivers/hwtracing/intel_th/gth.c
  26 @@ -597,7 +597,7 @@ static void intel_th_gth_unassign(struct
  27         othdev->output.port = -1;
  28         othdev->output.active = false;
  29         gth->output[port].output = NULL;
  30 -       for (master = 0; master < TH_CONFIGURABLE_MASTERS; master++)
  31 +       for (master = 0; master <= TH_CONFIGURABLE_MASTERS; master++)
  32                 if (gth->master[master] == port)
  33                         gth->master[master] = -1;
  34         spin_unlock(&gth->gth_lock);