From: Marcel Holtmann <marcel@holtmann.org>
To: Arnd Bergmann <arnd@kernel.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>,
Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
Mark Chen <Mark-YW.Chen@mediatek.com>,
Arnd Bergmann <arnd@arndb.de>, Kiran K <kiran.k@intel.com>,
Alain Michaud <alainm@chromium.org>,
Chethan T N <chethan.tumkur.narayan@intel.com>,
Abhishek Pandit-Subedi <abhishekpandit@chromium.org>,
Sathish Narasimman <nsathish41@gmail.com>,
Rocky Liao <rjliao@codeaurora.org>,
Ismael Ferreras Morezuelas <swyterzone@gmail.com>,
Hilda Wu <hildawu@realtek.com>, Trent Piepho <tpiepho@gmail.com>,
Bluetooth Kernel Mailing List <linux-bluetooth@vger.kernel.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Bluetooth: btusb: fix excessive stack usage
Date: Thu, 4 Feb 2021 18:13:19 +0100 [thread overview]
Message-ID: <24876961-6740-4C52-9F10-3E8056237DD0@holtmann.org> (raw)
In-Reply-To: <20210204154716.1823454-1-arnd@kernel.org>
Hi Arnd,
> Enlarging the size of 'struct btmtk_hci_wmt_cmd' makes it no longer
> fit on the kernel stack, as seen from this compiler warning:
>
> drivers/bluetooth/btusb.c:3365:12: error: stack frame size of 1036 bytes in function 'btusb_mtk_hci_wmt_sync' [-Werror,-Wframe-larger-than=]
>
> Change the function to dynamically allocate the buffer instead.
> As there are other sleeping functions called from the same location,
> using GFP_KERNEL should be fine here, and the runtime overhead should
> not matter as this is rarely called.
>
> Unfortunately, I could not figure out why the message size is
> increased in the previous patch. Using dynamic allocation means
> any size is possible now, but there is still a range check that
> limits the total size (including the five-byte header) to 255
> bytes, so whatever was intended there is now undone.
>
> Fixes: 48c13301e6ba ("Bluetooth: btusb: Fine-tune mt7663 mechanism.")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> drivers/bluetooth/btusb.c | 24 +++++++++++++++---------
> 1 file changed, 15 insertions(+), 9 deletions(-)
patch has been applied to bluetooth-next tree.
Regards
Marcel
next prev parent reply other threads:[~2021-02-04 17:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-04 15:47 [PATCH] Bluetooth: btusb: fix excessive stack usage Arnd Bergmann
2021-02-04 17:13 ` Marcel Holtmann [this message]
2021-02-04 21:02 ` Trent Piepho
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