Re: [PATCH v8 17/24] coresight: cti: Fix remove sysfs link error

Mathieu Poirier
2020-08-17T16:17:25Z

On Fri, Aug 07, 2020 at 07:11:46PM +0800, Tingwei Zhang wrote:
> From: Mike Leach <mike.leach@linaro.org>
>
> CTI code to remove sysfs link to other devices on shutdown, incorrectly
> tries to remove a single ended link when these are all double ended. This
> implementation leaves elements in the link info structure undefined which
> results in a crash in recent tests for driver module unload.
>
> This patch corrects the link removal code.
>
> Fixes: 73274abb6557 (coresight: cti: Add in sysfs links to other coresight devices)

This should be:

Fixes: 73274abb6557 ("coresight: cti: Add in sysfs links to other coresight devices")

> Reported-by: Tingwei Zhang <tingwei@codeaurora.org>
> Signed-off-by: Mike Leach <mike.leach@linaro.org>
> ---
> drivers/hwtracing/coresight/coresight-cti.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-cti.c b/drivers/hwtracing/coresight/coresight-cti.c
> index 1f470c47ba70..1c34db7d1b1b 100644
> --- a/drivers/hwtracing/coresight/coresight-cti.c
> +++ b/drivers/hwtracing/coresight/coresight-cti.c
> @@ -511,12 +511,15 @@ static bool cti_add_sysfs_link(struct cti_drvdata *drvdata,
> return !link_err;
> }
>
> -static void cti_remove_sysfs_link(struct cti_trig_con *tc)
> +static void cti_remove_sysfs_link(struct cti_drvdata *drvdata,
> + struct cti_trig_con *tc)
> {
> struct coresight_sysfs_link link_info;
>
> + link_info.orig = drvdata->csdev;
> link_info.orig_name = tc->con_dev_name;
> link_info.target = tc->con_dev;
> + link_info.target_name = dev_name(&drvdata->csdev->dev);
> coresight_remove_sysfs_link(&link_info);
> }
>
> @@ -606,7 +609,7 @@ void cti_remove_assoc_from_csdev(struct coresight_device *csdev)
> ctidev = &ctidrv->ctidev;
> list_for_each_entry(tc, &ctidev->trig_cons, node) {
> if (tc->con_dev == csdev->ect_dev) {
> - cti_remove_sysfs_link(tc);
> + cti_remove_sysfs_link(ctidrv, tc);
> tc->con_dev = NULL;
> break;
> }
> @@ -658,7 +661,7 @@ static void cti_remove_conn_xrefs(struct cti_drvdata *drvdata)
> if (tc->con_dev) {
> coresight_set_assoc_ectdev_mutex(tc->con_dev,
> NULL);
> - cti_remove_sysfs_link(tc);
> + cti_remove_sysfs_link(drvdata, tc);

With the above:

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

> tc->con_dev = NULL;
> }
> }
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project