From: Mansur Alisha Shaik <mansur@codeaurora.org>
To: linux-media@vger.kernel.org, stanimir.varbanov@linaro.org
Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
vgarodia@codeaurora.org,
Mansur Alisha Shaik <mansur@codeaurora.org>
Subject: [PATCH v2 1/3] venus: core: handle race condititon for core ops
Date: Thu, 10 Sep 2020 18:14:14 +0530 [thread overview]
Message-ID: <1599741856-16239-2-git-send-email-mansur@codeaurora.org> (raw)
In-Reply-To: <1599741856-16239-1-git-send-email-mansur@codeaurora.org>
For core ops we are having only write protect but there
is no read protect, because of this in multthreading
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>
Acked-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
---
Changes in V2:
- Addressed review comments by stan by validating on top
- of https://lore.kernel.org/patchwork/project/lkml/list/?series=455962
drivers/media/platform/qcom/venus/hfi.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/media/platform/qcom/venus/hfi.c b/drivers/media/platform/qcom/venus/hfi.c
index a59022a..3137071 100644
--- a/drivers/media/platform/qcom/venus/hfi.c
+++ b/drivers/media/platform/qcom/venus/hfi.c
@@ -195,7 +195,7 @@ EXPORT_SYMBOL_GPL(hfi_session_create);
int hfi_session_init(struct venus_inst *inst, u32 pixfmt)
{
struct venus_core *core = inst->core;
- const struct hfi_ops *ops = core->ops;
+ const struct hfi_ops *ops;
int ret;
if (inst->state != INST_UNINIT)
@@ -204,10 +204,13 @@ int hfi_session_init(struct venus_inst *inst, u32 pixfmt)
inst->hfi_codec = to_codec_type(pixfmt);
reinit_completion(&inst->done);
+ mutex_lock(&core->lock);
+ ops = core->ops;
ret = ops->session_init(inst, inst->session_type, inst->hfi_codec);
if (ret)
return ret;
+ mutex_unlock(&core->lock);
ret = wait_session_msg(inst);
if (ret)
return ret;
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
next prev parent reply other threads:[~2020-09-10 12:47 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-10 12:44 [PATCH v2 0/3] Venus - Handle race conditions in concurrency Mansur Alisha Shaik
2020-09-10 12:44 ` Mansur Alisha Shaik [this message]
2020-09-11 10:10 ` [PATCH v2 1/3] venus: core: handle race condititon for core ops Stanimir Varbanov
2020-09-17 1:51 ` mansur
2020-09-10 12:44 ` [PATCH v2 2/3] venus: core: cancel pending work items in workqueue Mansur Alisha Shaik
2020-09-11 10:22 ` Stanimir Varbanov
2020-09-17 1:53 ` mansur
2020-09-10 12:44 ` [PATCH v2 3/3] venus: handle use after free for iommu_map/iommu_unmap Mansur Alisha Shaik
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1599741856-16239-2-git-send-email-mansur@codeaurora.org \
--to=mansur@codeaurora.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=stanimir.varbanov@linaro.org \
--cc=vgarodia@codeaurora.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).