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authorAlexander Shishkin <alexander.shishkin@linux.intel.com>2019-01-24 15:11:53 +0200
committerAlexander Shishkin <alexander.shishkin@linux.intel.com>2019-02-21 17:43:14 +0200
commit9ed3f22223c33347ed963e7c7019cf2956dd4e37 (patch)
treeed5d8fc6e40538ca8bac3256aebc291d0bef064b /drivers/hwtracing
parent1d2ef028bf9a9272c658782d9c75f60658770ba4 (diff)
downloadlinux-stericsson-9ed3f22223c33347ed963e7c7019cf2956dd4e37.tar.gz
intel_th: Don't reference unassigned outputs
When an output port driver is removed, also remove references to it from any masters. Failing to do this causes a NULL ptr dereference when configuring another output port: > BUG: unable to handle kernel NULL pointer dereference at 000000000000000d > RIP: 0010:master_attr_store+0x9d/0x160 [intel_th_gth] > Call Trace: > dev_attr_store+0x1b/0x30 > sysfs_kf_write+0x3c/0x50 > kernfs_fop_write+0x125/0x1a0 > __vfs_write+0x3a/0x190 > ? __vfs_write+0x5/0x190 > ? _cond_resched+0x1a/0x50 > ? rcu_all_qs+0x5/0xb0 > ? __vfs_write+0x5/0x190 > vfs_write+0xb8/0x1b0 > ksys_write+0x55/0xc0 > __x64_sys_write+0x1a/0x20 > do_syscall_64+0x5a/0x140 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Fixes: b27a6a3f97b9 ("intel_th: Add Global Trace Hub driver") CC: stable@vger.kernel.org # v4.4+ Reported-by: Ammy Yi <ammy.yi@intel.com>
Diffstat (limited to 'drivers/hwtracing')
-rw-r--r--drivers/hwtracing/intel_th/gth.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/hwtracing/intel_th/gth.c b/drivers/hwtracing/intel_th/gth.c
index 8426b7970c14..cc287cf6eb29 100644
--- a/drivers/hwtracing/intel_th/gth.c
+++ b/drivers/hwtracing/intel_th/gth.c
@@ -607,6 +607,7 @@ static void intel_th_gth_unassign(struct intel_th_device *thdev,
{
struct gth_device *gth = dev_get_drvdata(&thdev->dev);
int port = othdev->output.port;
+ int master;
if (thdev->host_mode)
return;
@@ -615,6 +616,9 @@ static void intel_th_gth_unassign(struct intel_th_device *thdev,
othdev->output.port = -1;
othdev->output.active = false;
gth->output[port].output = NULL;
+ for (master = 0; master < TH_CONFIGURABLE_MASTERS; master++)
+ if (gth->master[master] == port)
+ gth->master[master] = -1;
spin_unlock(&gth->gth_lock);
}