lkml.org 
[lkml]   [2022]   [Jul]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] PM: QoS: Add check to make sure CPU freq is non-negative
From
Gentle reminder,

Thanks,

Shivnandan

On 6/23/2022 12:16 PM, Shivnandan Kumar wrote:
> CPU frequency should never be non-negative.
> If some client driver calls freq_qos_update_request with some
> value greater than INT_MAX, then it will set max CPU freq at
> fmax but it will add plist node with some negative priority.
> plist node has priority from INT_MIN (highest) to INT_MAX
> (lowest). Once priority is set as negative, another client
> will not be able to reduce max CPU frequency. Adding check
> to make sure CPU freq is non-negative will fix this problem.
> Signed-off-by: Shivnandan Kumar <quic_kshivnan@quicinc.com>
>
> ---
> kernel/power/qos.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/power/qos.c b/kernel/power/qos.c
> index ec7e1e85923e..41e96fe34bfd 100644
> --- a/kernel/power/qos.c
> +++ b/kernel/power/qos.c
> @@ -531,7 +531,8 @@ int freq_qos_add_request(struct freq_constraints *qos,
> {
> int ret;
>
> - if (IS_ERR_OR_NULL(qos) || !req)
> + if (IS_ERR_OR_NULL(qos) || !req || value < FREQ_QOS_MIN_DEFAULT_VALUE
> + || value > FREQ_QOS_MAX_DEFAULT_VALUE)
> return -EINVAL;
>
> if (WARN(freq_qos_request_active(req),
> @@ -563,7 +564,8 @@ EXPORT_SYMBOL_GPL(freq_qos_add_request);
> */
> int freq_qos_update_request(struct freq_qos_request *req, s32 new_value)
> {
> - if (!req)
> + if (!req || new_value < FREQ_QOS_MIN_DEFAULT_VALUE ||
> + new_value > FREQ_QOS_MAX_DEFAULT_VALUE)
> return -EINVAL;
>
> if (WARN(!freq_qos_request_active(req),

\
 
 \ /
  Last update: 2022-07-06 08:32    [W:0.066 / U:0.692 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site