block/blk-throttle.c:1488:74: warning: 'snprintf' output may be truncated before the last format character
From: kernel test robot
Date: Sat Nov 18 2023 - 22:00:36 EST
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: b8f1fa2419c19c81bc386a6b350879ba54a573e1
commit: ada75b6e5b2a939401d4919dfaf2f2fc9484f68a blk-throttle: add interface to configure idle time threshold
date: 7 years ago
config: x86_64-randconfig-r031-20230816 (https://download.01.org/0day-ci/archive/20231119/202311191030.CRFJc6T4-lkp@xxxxxxxxx/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231119/202311191030.CRFJc6T4-lkp@xxxxxxxxx/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311191030.CRFJc6T4-lkp@xxxxxxxxx/
All warnings (new ones prefixed by >>):
block/blk-throttle.c:1675:13: warning: 'throtl_tg_is_idle' defined but not used [-Wunused-function]
1675 | static bool throtl_tg_is_idle(struct throtl_grp *tg)
| ^~~~~~~~~~~~~~~~~
block/blk-throttle.c: In function 'tg_prfill_limit':
>> block/blk-throttle.c:1488:74: warning: 'snprintf' output may be truncated before the last format character [-Wformat-truncation=]
1488 | snprintf(idle_time, sizeof(idle_time), " idle=%lu",
| ^
block/blk-throttle.c:1488:25: note: 'snprintf' output between 8 and 27 bytes into a destination of size 26
1488 | snprintf(idle_time, sizeof(idle_time), " idle=%lu",
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1489 | tg->idletime_threshold);
| ~~~~~~~~~~~~~~~~~~~~~~~
vim +/snprintf +1488 block/blk-throttle.c
1442
1443 static u64 tg_prfill_limit(struct seq_file *sf, struct blkg_policy_data *pd,
1444 int off)
1445 {
1446 struct throtl_grp *tg = pd_to_tg(pd);
1447 const char *dname = blkg_dev_name(pd->blkg);
1448 char bufs[4][21] = { "max", "max", "max", "max" };
1449 u64 bps_dft;
1450 unsigned int iops_dft;
1451 char idle_time[26] = "";
1452
1453 if (!dname)
1454 return 0;
1455
1456 if (off == LIMIT_LOW) {
1457 bps_dft = 0;
1458 iops_dft = 0;
1459 } else {
1460 bps_dft = U64_MAX;
1461 iops_dft = UINT_MAX;
1462 }
1463
1464 if (tg->bps_conf[READ][off] == bps_dft &&
1465 tg->bps_conf[WRITE][off] == bps_dft &&
1466 tg->iops_conf[READ][off] == iops_dft &&
1467 tg->iops_conf[WRITE][off] == iops_dft &&
1468 (off != LIMIT_LOW || tg->idletime_threshold ==
1469 tg->td->dft_idletime_threshold))
1470 return 0;
1471
1472 if (tg->bps_conf[READ][off] != bps_dft)
1473 snprintf(bufs[0], sizeof(bufs[0]), "%llu",
1474 tg->bps_conf[READ][off]);
1475 if (tg->bps_conf[WRITE][off] != bps_dft)
1476 snprintf(bufs[1], sizeof(bufs[1]), "%llu",
1477 tg->bps_conf[WRITE][off]);
1478 if (tg->iops_conf[READ][off] != iops_dft)
1479 snprintf(bufs[2], sizeof(bufs[2]), "%u",
1480 tg->iops_conf[READ][off]);
1481 if (tg->iops_conf[WRITE][off] != iops_dft)
1482 snprintf(bufs[3], sizeof(bufs[3]), "%u",
1483 tg->iops_conf[WRITE][off]);
1484 if (off == LIMIT_LOW) {
1485 if (tg->idletime_threshold == ULONG_MAX)
1486 strcpy(idle_time, " idle=max");
1487 else
> 1488 snprintf(idle_time, sizeof(idle_time), " idle=%lu",
1489 tg->idletime_threshold);
1490 }
1491
1492 seq_printf(sf, "%s rbps=%s wbps=%s riops=%s wiops=%s%s\n",
1493 dname, bufs[0], bufs[1], bufs[2], bufs[3], idle_time);
1494 return 0;
1495 }
1496
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