Re: drivers/bus/fsl-mc/dprc.c:494:9: warning: 'strncpy' specified bound 16 equals destination size

From: Kefeng Wang
Date: Wed Jul 27 2022 - 08:50:26 EST


On 2022/7/27 20:23, kernel test robot wrote:
Hi Kefeng,

Hi， it seems that my patch won't lead to this issue，but I could change strncpy to strscpy_pad to fix the warning,

https://lore.kernel.org/lkml/20220727125432.160233-1-wangkefeng.wang@xxxxxxxxxx/T/#u


FYI, the error/warning still remains.

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 39c3c396f8131f3db454c80e0fcfcdc54ed9ec01
commit: dd03762ab608e058c8f390ad9cf667e490089796 arm64: Enable KCSAN
date: 8 months ago
config: arm64-randconfig-c023-20220727 (https://download.01.org/0day-ci/archive/20220727/202207272044.M4FM7xVg-lkp@xxxxxxxxx/config)
compiler: aarch64-linux-gcc (GCC) 12.1.0
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
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dd03762ab608e058c8f390ad9cf667e490089796
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout dd03762ab608e058c8f390ad9cf667e490089796
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash drivers/bus/fsl-mc/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

drivers/bus/fsl-mc/dprc.c: In function 'dprc_get_obj':
drivers/bus/fsl-mc/dprc.c:453:9: warning: 'strncpy' output may be truncated copying 15 bytes from a string of length 15 [-Wstringop-truncation]
453 | strncpy(obj_desc->type, rsp_params->type, 16);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/bus/fsl-mc/dprc.c:455:9: warning: 'strncpy' output may be truncated copying 15 bytes from a string of length 15 [-Wstringop-truncation]
455 | strncpy(obj_desc->label, rsp_params->label, 16);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/bus/fsl-mc/dprc.c: In function 'dprc_set_obj_irq':
drivers/bus/fsl-mc/dprc.c:494:9: warning: 'strncpy' specified bound 16 equals destination size [-Wstringop-truncation]
494 | strncpy(cmd_params->obj_type, obj_type, 16);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/bus/fsl-mc/dprc.c: In function 'dprc_get_obj_region':
drivers/bus/fsl-mc/dprc.c:567:9: warning: 'strncpy' specified bound 16 equals destination size [-Wstringop-truncation]
567 | strncpy(cmd_params->obj_type, obj_type, 16);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/strncpy +494 drivers/bus/fsl-mc/dprc.c

31c889653c10ddaf drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-03-05 460
e9bf3f206bd5e61e drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-24 461 /**
e9bf3f206bd5e61e drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-24 462 * dprc_set_obj_irq() - Set IRQ information for object to trigger an interrupt.
e9bf3f206bd5e61e drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-24 463 * @mc_io: Pointer to MC portal's I/O object
e9bf3f206bd5e61e drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-24 464 * @cmd_flags: Command flags; one or more of 'MC_CMD_FLAG_'
e9bf3f206bd5e61e drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-24 465 * @token: Token of DPRC object
e9bf3f206bd5e61e drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-24 466 * @obj_type: Type of the object to set its IRQ
e9bf3f206bd5e61e drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-24 467 * @obj_id: ID of the object to set its IRQ
e9bf3f206bd5e61e drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-24 468 * @irq_index: The interrupt index to configure
e9bf3f206bd5e61e drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-24 469 * @irq_cfg: IRQ configuration
e9bf3f206bd5e61e drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-24 470 *
e9bf3f206bd5e61e drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-24 471 * Return: '0' on Success; Error code otherwise.
e9bf3f206bd5e61e drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-24 472 */
1ee695fab32e25ff drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-23 473 int dprc_set_obj_irq(struct fsl_mc_io *mc_io,
ba72f25b2588e1ac drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-25 474 u32 cmd_flags,
ba72f25b2588e1ac drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-25 475 u16 token,
1ee695fab32e25ff drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-23 476 char *obj_type,
1ee695fab32e25ff drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-23 477 int obj_id,
ba72f25b2588e1ac drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-25 478 u8 irq_index,
1ee695fab32e25ff drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-23 479 struct dprc_irq_cfg *irq_cfg)
1ee695fab32e25ff drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-23 480 {
5b04cedeca188874 drivers/bus/fsl-mc/dprc.c Ioana Ciornei 2018-03-15 481 struct fsl_mc_command cmd = { 0 };
9989b59961a8ad55 drivers/staging/fsl-mc/bus/dprc.c Ioana Radulescu 2016-06-22 482 struct dprc_cmd_set_obj_irq *cmd_params;
1ee695fab32e25ff drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-23 483
1ee695fab32e25ff drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-23 484 /* prepare command */
1ee695fab32e25ff drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-23 485 cmd.header = mc_encode_cmd_header(DPRC_CMDID_SET_OBJ_IRQ,
1ee695fab32e25ff drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-23 486 cmd_flags,
1ee695fab32e25ff drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-23 487 token);
9989b59961a8ad55 drivers/staging/fsl-mc/bus/dprc.c Ioana Radulescu 2016-06-22 488 cmd_params = (struct dprc_cmd_set_obj_irq *)cmd.params;
9989b59961a8ad55 drivers/staging/fsl-mc/bus/dprc.c Ioana Radulescu 2016-06-22 489 cmd_params->irq_val = cpu_to_le32(irq_cfg->val);
9989b59961a8ad55 drivers/staging/fsl-mc/bus/dprc.c Ioana Radulescu 2016-06-22 490 cmd_params->irq_index = irq_index;
9989b59961a8ad55 drivers/staging/fsl-mc/bus/dprc.c Ioana Radulescu 2016-06-22 491 cmd_params->irq_addr = cpu_to_le64(irq_cfg->paddr);
9989b59961a8ad55 drivers/staging/fsl-mc/bus/dprc.c Ioana Radulescu 2016-06-22 492 cmd_params->irq_num = cpu_to_le32(irq_cfg->irq_num);
9989b59961a8ad55 drivers/staging/fsl-mc/bus/dprc.c Ioana Radulescu 2016-06-22 493 cmd_params->obj_id = cpu_to_le32(obj_id);
9989b59961a8ad55 drivers/staging/fsl-mc/bus/dprc.c Ioana Radulescu 2016-06-22 @494 strncpy(cmd_params->obj_type, obj_type, 16);
9989b59961a8ad55 drivers/staging/fsl-mc/bus/dprc.c Ioana Radulescu 2016-06-22 495 cmd_params->obj_type[15] = '\0';
1ee695fab32e25ff drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-23 496
1ee695fab32e25ff drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-23 497 /* send command to mc*/
1ee695fab32e25ff drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-23 498 return mc_send_command(mc_io, &cmd);
1ee695fab32e25ff drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-23 499 }
c9d57ea0b6fb0bc0 drivers/staging/fsl-mc/bus/dprc.c Laurentiu Tudor 2017-11-17 500 EXPORT_SYMBOL_GPL(dprc_set_obj_irq);
1ee695fab32e25ff drivers/staging/fsl-mc/bus/dprc.c J. German Rivera 2015-09-23 501

:::::: The code at line 494 was first introduced by commit
:::::: 9989b59961a8ad55d92df4588b556f0c6c838ec7 staging: fsl-mc: convert mc command build/parse to use C structs

:::::: TO: Ioana Radulescu <ruxandra.radulescu@xxxxxxx>
:::::: CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>