From: Kees Cook <keescook@chromium•org>
To: Marc Kleine-Budde <mkl@pengutronix•de>
Cc: linux-kernel@vger•kernel.org,
"Gustavo A. R. Silva" <gustavoars@kernel•org>,
Arnd Bergmann <arnd@arndb•de>,
Ayush Sawal <ayush.sawal@chelsio•com>,
Vinay Kumar Yadav <vinay.yadav@chelsio•com>,
Rohit Maheshwari <rohitm@chelsio•com>,
Herbert Xu <herbert@gondor•apana.org.au>,
"David S. Miller" <davem@davemloft•net>,
Kalle Valo <kvalo@codeaurora•org>,
Jakub Kicinski <kuba@kernel•org>,
Stanislaw Gruszka <stf_xl@wp•pl>,
Luca Coelho <luciano.coelho@intel•com>,
"James E.J. Bottomley" <jejb@linux•ibm.com>,
"Martin K. Petersen" <martin.petersen@oracle•com>,
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Subject: Re: [PATCH v2 2/5] treewide: Replace open-coded flex arrays in unions
Date: Fri, 27 Aug 2021 09:17:37 -0700 [thread overview]
Message-ID: <202108270915.B4DD070AF@keescook> (raw)
In-Reply-To: <20210826062452.jekmoo43f4xu5jxk@pengutronix.de>
On Thu, Aug 26, 2021 at 08:24:52AM +0200, Marc Kleine-Budde wrote:
> [...]
> BTW: Is there opportunity for conversion, too?
>
> | drivers/net/can/peak_canfd/peak_pciefd_main.c:146:32: warning: array of flexible structures
Untested potential solution:
diff --git a/drivers/net/can/peak_canfd/peak_pciefd_main.c b/drivers/net/can/peak_canfd/peak_pciefd_main.c
index 1df3c4b54f03..efa2b5a52bd7 100644
--- a/drivers/net/can/peak_canfd/peak_pciefd_main.c
+++ b/drivers/net/can/peak_canfd/peak_pciefd_main.c
@@ -143,7 +143,11 @@ struct pciefd_rx_dma {
__le32 irq_status;
__le32 sys_time_low;
__le32 sys_time_high;
- struct pucan_rx_msg msg[];
+ /*
+ * with "msg" being pciefd_irq_rx_cnt(priv->irq_status)-many
+ * variable-sized struct pucan_rx_msg following.
+ */
+ __le32 msg[];
} __packed __aligned(4);
/* Tx Link record */
@@ -327,7 +331,7 @@ static irqreturn_t pciefd_irq_handler(int irq, void *arg)
/* handle rx messages (if any) */
peak_canfd_handle_msgs_list(&priv->ucan,
- rx_dma->msg,
+ (struct pucan_rx_msg *)rx_dma->msg,
pciefd_irq_rx_cnt(priv->irq_status));
/* handle tx link interrupt (if any) */
It's not great, but it's also not strictly a flex array, in the sense
that since struct pucan_rx_msg is a variable size, the compiler cannot
reason about the size of struct pciefd_rx_dma based only on the
irq_status encoding...
--
Kees Cook
next prev parent reply other threads:[~2021-08-27 16:17 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210826050458.1540622-1-keescook@chromium.org>
2021-08-26 5:04 ` [PATCH v2 2/5] treewide: Replace open-coded flex arrays in unions Kees Cook
2021-08-26 6:24 ` Marc Kleine-Budde
2021-08-27 16:08 ` Kees Cook
2021-08-27 17:08 ` Marc Kleine-Budde
2021-08-27 16:17 ` Kees Cook [this message]
2021-08-28 7:31 ` Vincent MAILHOL
2021-08-26 7:36 ` Vincent MAILHOL
2021-08-26 15:39 ` Kees Cook
2021-08-26 5:04 ` [PATCH v2 3/5] treewide: Replace 0-element memcpy() destinations with flexible arrays Kees Cook
2021-08-26 5:24 ` Keith Packard
2021-08-26 5:51 ` Kees Cook
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