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 > Cc: Marc Kleine-Budde > Cc: "David S. Miller" > Cc: Jakub Kicinski > Cc: linux-can@vger.kernel.org > Cc: netdev@vger.kernel.org > Signed-off-by: Kees Cook Acked-by: Marc Kleine-Budde > - 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 |