On 27.03.2021 18:16:14, kernel test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > master > head: 0f4498cef9f5cd18d7c6639a2a902ec1edc5be4e > commit: eb79a267c9b3e608e7762a1b221428f37ace3aa3 can: mcp251xfd: rename all > remaining occurrence to mcp251xfd > date: 6 months ago > config: mips-randconfig-r035-20210327 (attached as .config) > compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project > d50fe9f0d6b9ee61df8830a67ea0a33c27a637e7) > reproduce (this is a W=1 build): > wget > https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O > ~/bin/make.cross > chmod +x ~/bin/make.cross > # install mips cross compiling tool for clang build > # apt-get install binutils-mips-linux-gnu > # > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=eb79a267c9b3e608e7762a1b221428f37ace3aa3 > git remote add linus > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > git fetch --no-tags linus master > git checkout eb79a267c9b3e608e7762a1b221428f37ace3aa3 > # save the attached .config to linux build tree > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <l...@intel.com> > > All warnings (new ones prefixed by >>):
[...]
> >> drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c:2267:16: warning: taking
> >> address of packed member 'hw_tx_obj' of class or structure
> >> 'mcp251xfd_tx_obj_load_buf::(anonymous)' may result in an unaligned
> >> pointer value [-Waddress-of-packed-member]
> hw_tx_obj = &load_buf->crc.hw_tx_obj;
> ^~~~~~~~~~~~~~~~~~~~~~~
> drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c:2269:16: warning: taking
> address of packed member 'hw_tx_obj' of class or structure
> 'mcp251xfd_tx_obj_load_buf::(anonymous)' may result in an unaligned pointer
> value [-Waddress-of-packed-member]
> hw_tx_obj = &load_buf->nocrc.hw_tx_obj;
> ^~~~~~~~~~~~~~~~~~~~~~~~~
> 4 warnings and 1 error generated.
That warning is technically correct, hw_tx_obj is an unaligned pointer in
the first warning, but...
> vim +2267 drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
>
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2215 static void
> eb79a267c9b3e6 drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c Marc
> Kleine-Budde 2020-09-30 2216 mcp251xfd_tx_obj_from_skb(const struct
> mcp251xfd_priv *priv,
> eb79a267c9b3e6 drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c Marc
> Kleine-Budde 2020-09-30 2217 struct mcp251xfd_tx_obj
> *tx_obj,
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2218 const struct sk_buff
> *skb,
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2219 unsigned int seq)
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2220 {
[...]
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2265 load_buf = &tx_obj->buf;
> eb79a267c9b3e6 drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c Marc
> Kleine-Budde 2020-09-30 2266 if (priv->devtype_data.quirks &
> MCP251XFD_QUIRK_CRC_TX)
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 @2267 hw_tx_obj =
> &load_buf->crc.hw_tx_obj;
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2268 else
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2269 hw_tx_obj =
> &load_buf->nocrc.hw_tx_obj;
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2270
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2271 put_unaligned_le32(id, &hw_tx_obj->id);
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2272 put_unaligned_le32(flags,
> &hw_tx_obj->flags);
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2273
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2274 /* Clear data at end of CAN frame */
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2275 offset = round_down(cfd->len, sizeof(u32));
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2276 len = round_up(can_dlc2len(dlc),
> sizeof(u32)) - offset;
> eb79a267c9b3e6 drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c Marc
> Kleine-Budde 2020-09-30 2277 if (MCP251XFD_SANITIZE_CAN && len)
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2278 memset(hw_tx_obj->data + offset,
> 0x0, len);
> 55e5b97f003e85 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c Marc
> Kleine-Budde 2020-09-18 2279 memcpy(hw_tx_obj->data, cfd->data,
> cfd->len);
...it's only accessed via put_unaligned_* and memset()/memcpy().
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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