c812948744
The handling of CAN bus errors typically consist of allocating a CAN
error SKB using alloc_can_err_skb() followed by stats handling and
filling the error details in the newly allocated CAN error SKB. Even
if the allocation of the SKB fails the stats handling should not be
skipped.
The common pattern in CAN drivers is to allocate the skb and work on
the struct can_frame pointer "cf", if it has been assigned by
alloc_can_err_skb().
| skb = alloc_can_err_skb(priv->ndev, &cf);
|
| /* RX errors */
| if (bdiag1 & (MCP251XFD_REG_BDIAG1_DCRCERR |
| MCP251XFD_REG_BDIAG1_NCRCERR)) {
| netdev_dbg(priv->ndev, "CRC error\n");
|
| stats->rx_errors++;
| if (cf)
| cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
| }
In case of an OOM alloc_can_err_skb() returns NULL, but doesn't set
"cf" to NULL as well. For the above pattern to work the "cf" has to be
initialized to NULL, which is easily forgotten.
To solve this kind of problems, set "cf" to NULL if
alloc_can_err_skb() returns NULL.
Link: https://lore.kernel.org/r/20210402102245.1512583-1-mkl@pengutronix.de
Suggested-by: Vincent MAILHOL <mailhol.vincent@wanadoo.fr>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.