Re: [PATCH v2 59/63] can: flexcan: Use struct_group() to zero struct flexcan_regs regions
From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: 2021-08-18 06:27:46
Also in:
dri-devel, linux-block, linux-can, linux-hardening, linux-kbuild, linux-staging, lkml, netdev
On 17.08.2021 23:05:29, Kees Cook wrote:
In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.
Add struct_group() to mark both regions of struct flexcan_regs that get
initialized to zero. Avoid the future warnings:
In function 'fortify_memset_chk',
inlined from 'memset_io' at ./include/asm-generic/io.h:1169:2,
inlined from 'flexcan_ram_init' at drivers/net/can/flexcan.c:1403:2:
./include/linux/fortify-string.h:199:4: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
199 | __write_overflow_field(p_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In function 'fortify_memset_chk',
inlined from 'memset_io' at ./include/asm-generic/io.h:1169:2,
inlined from 'flexcan_ram_init' at drivers/net/can/flexcan.c:1408:3:
./include/linux/fortify-string.h:199:4: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
199 | __write_overflow_field(p_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Cc: Wolfgang Grandegger <redacted>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: linux-can@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <redacted>Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
- memset_io(®s->mb[0][0], 0, - offsetof(struct flexcan_regs, rx_smb1[3]) - - offsetof(struct flexcan_regs, mb[0][0]) + 0x4); + memset_io(®s->init, 0, sizeof(regs->init));
This even makes the code more readable! \o/
if (priv->can.ctrlmode & CAN_CTRLMODE_FD) - memset_io(®s->tx_smb_fd[0], 0, - offsetof(struct flexcan_regs, rx_smb1_fd[17]) - - offsetof(struct flexcan_regs, tx_smb_fd[0]) + 0x4); + memset_io(®s->init_fd, 0, sizeof(regs->init_fd)); reg_ctrl2 &= ~FLEXCAN_CTRL2_WRMFRZ; priv->write(reg_ctrl2, ®s->ctrl2);
regards, 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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