From: Evan Green <evgreen@chromium.org>
To: Maulik Shah <mkshah@codeaurora.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>,
Andy Gross <agross@kernel.org>,
linux-arm-msm <linux-arm-msm@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Stephen Boyd <swboyd@chromium.org>,
Doug Anderson <dianders@chromium.org>,
Rajendra Nayak <rnayak@codeaurora.org>,
Lina Iyer <ilina@codeaurora.org>,
lsrao@codeaurora.org
Subject: Re: [PATCH 2/3] soc: qcom: rpmh: Update rpm_msgs offset address and add list_del
Date: Tue, 4 Feb 2020 16:31:26 -0800 [thread overview]
Message-ID: <CAE=gft7gPS+hhnDP+uTn3is6s9=Nspbb4PL0bZ025Tq1Zpth8Q@mail.gmail.com> (raw)
In-Reply-To: <1580796831-18996-3-git-send-email-mkshah@codeaurora.org>
On Mon, Feb 3, 2020 at 10:14 PM Maulik Shah <mkshah@codeaurora.org> wrote:
>
> rpm_msgs are copied in continuously allocated memory during write_batch.
> Update request pointer to correctly point to designated area for rpm_msgs.
>
> While at this also add missing list_del before freeing rpm_msgs.
>
> Signed-off-by: Maulik Shah <mkshah@codeaurora.org>
> ---
> drivers/soc/qcom/rpmh.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
> index c3d6f00..04c7805 100644
> --- a/drivers/soc/qcom/rpmh.c
> +++ b/drivers/soc/qcom/rpmh.c
> @@ -65,7 +65,7 @@ struct cache_req {
> struct batch_cache_req {
> struct list_head list;
> int count;
> - struct rpmh_request rpm_msgs[];
> + struct rpmh_request *rpm_msgs;
> };
>
> static struct rpmh_ctrlr *get_rpmh_ctrlr(const struct device *dev)
> @@ -327,8 +327,10 @@ static void invalidate_batch(struct rpmh_ctrlr *ctrlr)
> unsigned long flags;
>
> spin_lock_irqsave(&ctrlr->cache_lock, flags);
> - list_for_each_entry_safe(req, tmp, &ctrlr->batch_cache, list)
> + list_for_each_entry_safe(req, tmp, &ctrlr->batch_cache, list) {
> + list_del(&req->list);
> kfree(req);
> + }
> INIT_LIST_HEAD(&ctrlr->batch_cache);
Hm, I don't get it. list_for_each_entry_safe ensures you can traverse
the list while freeing it behind you. ctrlr->batch_cache is now a
bogus list, but is re-inited with the lock held. From my reading,
there doesn't seem to be anything wrong with the current code. Can you
elaborate on the bug you found?
> spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
> }
> @@ -377,10 +379,11 @@ int rpmh_write_batch(const struct device *dev, enum rpmh_state state,
> return -ENOMEM;
>
> req = ptr;
> + rpm_msgs = ptr + sizeof(*req);
> compls = ptr + sizeof(*req) + count * sizeof(*rpm_msgs);
>
> req->count = count;
> - rpm_msgs = req->rpm_msgs;
> + req->rpm_msgs = rpm_msgs;
I don't really understand what this is fixing either, can you explain?
next prev parent reply other threads:[~2020-02-05 0:32 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-04 6:13 [PATCH 0/3] Misc stability fixes and optimization for rpmh driver Maulik Shah
2020-02-04 6:13 ` [PATCH 1/3] soc: qcom: rpmh: Update dirty flag only when data changes Maulik Shah
2020-02-05 0:35 ` Evan Green
2020-02-05 4:14 ` Maulik Shah
2020-02-05 18:07 ` Evan Green
2020-02-12 11:41 ` Maulik Shah
2020-02-04 6:13 ` [PATCH 2/3] soc: qcom: rpmh: Update rpm_msgs offset address and add list_del Maulik Shah
2020-02-05 0:31 ` Evan Green [this message]
2020-02-05 5:11 ` Maulik Shah
2020-02-05 18:21 ` Evan Green
2020-02-12 12:15 ` Maulik Shah
2020-02-21 1:05 ` Evan Green
2020-02-04 6:13 ` [PATCH 3/3] soc: qcom: rpmh: Invalidate sleep and wake TCS before flushing new data Maulik Shah
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