Messages in this thread | | | Date | Tue, 17 May 2022 08:25:04 +0200 | Subject | Re: [PATCH net v2] NFC: nci: fix sleep in atomic context bugs caused by nci_skb_alloc | From | Krzysztof Kozlowski <> |
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On 17/05/2022 03:25, Duoming Zhou wrote: > There are sleep in atomic context bugs when the request to secure > element of st-nci is timeout. The root cause is that nci_skb_alloc > with GFP_KERNEL parameter is called in st_nci_se_wt_timeout which is > a timer handler. The call paths that could trigger bugs are shown below: > > (interrupt context 1) > st_nci_se_wt_timeout > nci_hci_send_event > nci_hci_send_data > nci_skb_alloc(..., GFP_KERNEL) //may sleep > > (interrupt context 2) > st_nci_se_wt_timeout > nci_hci_send_event > nci_hci_send_data > nci_send_data > nci_queue_tx_data_frags > nci_skb_alloc(..., GFP_KERNEL) //may sleep > > This patch changes allocation mode of nci_skb_alloc from GFP_KERNEL to > GFP_ATOMIC in order to prevent atomic context sleeping. The GFP_ATOMIC > flag makes memory allocation operation could be used in atomic context. > > Fixes: ed06aeefdac3 ("nfc: st-nci: Rename st21nfcb to st-nci") > Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> > --- > Changes in v2: > - Change the Fixes tag to commit st_nci_se_wt_timeout was added.
Please add Acked-by/Reviewed-by tags when posting new versions. However, there's no need to repost patches *only* to add the tags. The upstream maintainer will do that for acks received on the version they apply.
https://elixir.bootlin.com/linux/v5.13/source/Documentation/process/submitting-patches.rst#L543
If a tag was not added on purpose, please state why and what changed.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Best regards, Krzysztof
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