summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorMansur Alisha Shaik <mansur@codeaurora.org>2020-09-24 09:59:44 +0300
committerMauro Carvalho Chehab <mchehab+huawei@kernel.org>2020-11-17 08:54:36 +0300
commit9696960f1347f28bde0ab5aeaafe1fbc8d477206 (patch)
tree757faa0a84e1c09dfa8f5bb1d646da51741fbc75
parentb57cf6a0a8894d5e89848e15e8f5e4cf36124aeb (diff)
downloadlinux-9696960f1347f28bde0ab5aeaafe1fbc8d477206.tar.xz
media: venus: core: handle race condititon for core ops
For core ops we are having only write protect but there is no read protect, because of this in multithreading and concurrency, one CPU core is reading without wait which is causing the NULL pointer dereferece crash. one such scenario is as show below, where in one CPU core, core->ops becoming NULL and in another CPU core calling core->ops->session_init(). CPU: core-7: Call trace: hfi_session_init+0x180/0x1dc [venus_core] vdec_queue_setup+0x9c/0x364 [venus_dec] vb2_core_reqbufs+0x1e4/0x368 [videobuf2_common] vb2_reqbufs+0x4c/0x64 [videobuf2_v4l2] v4l2_m2m_reqbufs+0x50/0x84 [v4l2_mem2mem] v4l2_m2m_ioctl_reqbufs+0x2c/0x38 [v4l2_mem2mem] v4l_reqbufs+0x4c/0x5c __video_do_ioctl+0x2b0/0x39c CPU: core-0: Call trace: venus_shutdown+0x98/0xfc [venus_core] venus_sys_error_handler+0x64/0x148 [venus_core] process_one_work+0x210/0x3d0 worker_thread+0x248/0x3f4 kthread+0x11c/0x12c Signed-off-by: Mansur Alisha Shaik <mansur@codeaurora.org> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
-rw-r--r--drivers/media/platform/qcom/venus/hfi.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/media/platform/qcom/venus/hfi.c b/drivers/media/platform/qcom/venus/hfi.c
index a59022adb14c..638ed5cfe05e 100644
--- a/drivers/media/platform/qcom/venus/hfi.c
+++ b/drivers/media/platform/qcom/venus/hfi.c
@@ -198,6 +198,18 @@ int hfi_session_init(struct venus_inst *inst, u32 pixfmt)
const struct hfi_ops *ops = core->ops;
int ret;
+ /*
+ * If core shutdown is in progress or if we are in system
+ * recovery, return an error as during system error recovery
+ * session_init() can't pass successfully
+ */
+ mutex_lock(&core->lock);
+ if (!core->ops || core->sys_error) {
+ mutex_unlock(&core->lock);
+ return -EIO;
+ }
+ mutex_unlock(&core->lock);
+
if (inst->state != INST_UNINIT)
return -EINVAL;