block/blk-throttle.c:1498:43: warning: '%lu' directive output may be truncated writing between 1 and 20 bytes into a region of size 17
From: kernel test robot
Date: Sun Nov 19 2023 - 05:45:36 EST
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 037266a5f7239ead1530266f7d7af153d2a867fa
commit: ec80991d6fc2cb17abfc5427ac1512d2ccd40589 blk-throttle: add interface for per-cgroup target latency
date: 7 years ago
config: x86_64-randconfig-r031-20230816 (https://download.01.org/0day-ci/archive/20231119/202311191805.T3V1HGnn-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/20231119/202311191805.T3V1HGnn-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/202311191805.T3V1HGnn-lkp@xxxxxxxxx/
All warnings (new ones prefixed by >>):
block/blk-throttle.c: In function 'tg_prfill_limit':
block/blk-throttle.c:1491:74: warning: 'snprintf' output may be truncated before the last format character [-Wformat-truncation=]
1491 | snprintf(idle_time, sizeof(idle_time), " idle=%lu",
| ^
block/blk-throttle.c:1491:25: note: 'snprintf' output between 8 and 27 bytes into a destination of size 26
1491 | snprintf(idle_time, sizeof(idle_time), " idle=%lu",
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1492 | tg->idletime_threshold);
| ~~~~~~~~~~~~~~~~~~~~~~~
>> block/blk-throttle.c:1498:43: warning: '%lu' directive output may be truncated writing between 1 and 20 bytes into a region of size 17 [-Wformat-truncation=]
1498 | " latency=%lu", tg->latency_target);
| ^~~
block/blk-throttle.c:1498:33: note: directive argument in the range [0, 18446744073709551614]
1498 | " latency=%lu", tg->latency_target);
| ^~~~~~~~~~~~~~
block/blk-throttle.c:1497:25: note: 'snprintf' output between 11 and 30 bytes into a destination of size 26
1497 | snprintf(latency_time, sizeof(latency_time),
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1498 | " latency=%lu", tg->latency_target);
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
vim +1498 block/blk-throttle.c
1443
1444 static u64 tg_prfill_limit(struct seq_file *sf, struct blkg_policy_data *pd,
1445 int off)
1446 {
1447 struct throtl_grp *tg = pd_to_tg(pd);
1448 const char *dname = blkg_dev_name(pd->blkg);
1449 char bufs[4][21] = { "max", "max", "max", "max" };
1450 u64 bps_dft;
1451 unsigned int iops_dft;
1452 char idle_time[26] = "";
1453 char latency_time[26] = "";
1454
1455 if (!dname)
1456 return 0;
1457
1458 if (off == LIMIT_LOW) {
1459 bps_dft = 0;
1460 iops_dft = 0;
1461 } else {
1462 bps_dft = U64_MAX;
1463 iops_dft = UINT_MAX;
1464 }
1465
1466 if (tg->bps_conf[READ][off] == bps_dft &&
1467 tg->bps_conf[WRITE][off] == bps_dft &&
1468 tg->iops_conf[READ][off] == iops_dft &&
1469 tg->iops_conf[WRITE][off] == iops_dft &&
1470 (off != LIMIT_LOW ||
1471 (tg->idletime_threshold == tg->td->dft_idletime_threshold &&
1472 tg->latency_target == DFL_LATENCY_TARGET)))
1473 return 0;
1474
1475 if (tg->bps_conf[READ][off] != bps_dft)
1476 snprintf(bufs[0], sizeof(bufs[0]), "%llu",
1477 tg->bps_conf[READ][off]);
1478 if (tg->bps_conf[WRITE][off] != bps_dft)
1479 snprintf(bufs[1], sizeof(bufs[1]), "%llu",
1480 tg->bps_conf[WRITE][off]);
1481 if (tg->iops_conf[READ][off] != iops_dft)
1482 snprintf(bufs[2], sizeof(bufs[2]), "%u",
1483 tg->iops_conf[READ][off]);
1484 if (tg->iops_conf[WRITE][off] != iops_dft)
1485 snprintf(bufs[3], sizeof(bufs[3]), "%u",
1486 tg->iops_conf[WRITE][off]);
1487 if (off == LIMIT_LOW) {
1488 if (tg->idletime_threshold == ULONG_MAX)
1489 strcpy(idle_time, " idle=max");
1490 else
1491 snprintf(idle_time, sizeof(idle_time), " idle=%lu",
1492 tg->idletime_threshold);
1493
1494 if (tg->latency_target == ULONG_MAX)
1495 strcpy(latency_time, " latency=max");
1496 else
1497 snprintf(latency_time, sizeof(latency_time),
> 1498 " latency=%lu", tg->latency_target);
1499 }
1500
1501 seq_printf(sf, "%s rbps=%s wbps=%s riops=%s wiops=%s%s%s\n",
1502 dname, bufs[0], bufs[1], bufs[2], bufs[3], idle_time,
1503 latency_time);
1504 return 0;
1505 }
1506
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