2019-10-19 08:30:20

by Georgi Djakov

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Subject: [PATCH] interconnect: Add locking in icc_set_tag()

We must ensure that the tag is not changed while we aggregate the
requests. Currently the icc_set_tag() is not using any locks and this
may cause the values to be aggregated incorrectly. Fix this by acquiring
the icc_lock while we set the tag.

Fixes: 127ab2cc5f19 ("interconnect: Add support for path tags")
Signed-off-by: Georgi Djakov <[email protected]>
---
drivers/interconnect/core.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index e24092558c29..4940c0741d40 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -408,8 +408,12 @@ void icc_set_tag(struct icc_path *path, u32 tag)
if (!path)
return;

+ mutex_lock(&icc_lock);
+
for (i = 0; i < path->num_nodes; i++)
path->reqs[i].tag = tag;
+
+ mutex_unlock(&icc_lock);
}
EXPORT_SYMBOL_GPL(icc_set_tag);


2019-10-19 08:47:17

by Bjorn Andersson

[permalink] [raw]
Subject: Re: [PATCH] interconnect: Add locking in icc_set_tag()

On Fri 18 Oct 07:17 PDT 2019, Georgi Djakov wrote:

> We must ensure that the tag is not changed while we aggregate the
> requests. Currently the icc_set_tag() is not using any locks and this
> may cause the values to be aggregated incorrectly. Fix this by acquiring
> the icc_lock while we set the tag.
>
> Fixes: 127ab2cc5f19 ("interconnect: Add support for path tags")
> Signed-off-by: Georgi Djakov <[email protected]>

Reviewed-by: Bjorn Andersson <[email protected]>

> ---
> drivers/interconnect/core.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
> index e24092558c29..4940c0741d40 100644
> --- a/drivers/interconnect/core.c
> +++ b/drivers/interconnect/core.c
> @@ -408,8 +408,12 @@ void icc_set_tag(struct icc_path *path, u32 tag)
> if (!path)
> return;
>
> + mutex_lock(&icc_lock);
> +
> for (i = 0; i < path->num_nodes; i++)
> path->reqs[i].tag = tag;
> +
> + mutex_unlock(&icc_lock);
> }
> EXPORT_SYMBOL_GPL(icc_set_tag);
>