[android-common:android13-5.10 1/1] fs/f2fs/iostat.c:210 __update_iostat_latency() error: buffer overflow 'io_lat->sum_lat[idx]' 3 <= 3

[kernel test robot <lkp@intel.com>]

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
TO: cros-kernel-buildreports@googlegroups.com

tree:   https://android.googlesource.com/kernel/common android13-5.10
head:   68b45855d7865a3c7836a9f017f8c337f3a15367
commit: d95bf22a4d1cbeebc288b87af27f0ea181a57218 [1/1] f2fs: introduce periodic iostat io latency traces
:::::: branch date: 4 days ago
:::::: commit date: 4 years, 11 months ago
config: x86_64-randconfig-161-20260728 (https://download.01.org/0day-ci/archive/20260729/202607290313.p90dfy5i-lkp@intel.com/config)
compiler: clang version 24.0.0git (https://github.com/llvm/llvm-project 890b11e09e45e9d8b29f2f94f22052be3934e757)
smatch: v0.5.0-9187-g5189e3fb

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@intel.com>
| Reported-by: Dan Carpenter <error27@gmail.com>
| Closes: https://lore.kernel.org/r/202607290313.p90dfy5i-lkp@intel.com/

New smatch warnings:
fs/f2fs/iostat.c:210 __update_iostat_latency() error: buffer overflow 'io_lat->sum_lat[idx]' 3 <= 3
fs/f2fs/iostat.c:211 __update_iostat_latency() error: buffer overflow 'io_lat->bio_cnt[idx]' 3 <= 3
fs/f2fs/iostat.c:212 __update_iostat_latency() error: buffer overflow 'io_lat->peak_lat[idx]' 3 <= 3

Old smatch warnings:
fs/f2fs/iostat.c:213 __update_iostat_latency() error: buffer overflow 'io_lat->peak_lat[idx]' 3 <= 3

vim +210 fs/f2fs/iostat.c

d20508aceea564 Daeho Jeong 2021-08-19  182  
d95bf22a4d1cbe Daeho Jeong 2021-08-20  183  static inline void __update_iostat_latency(struct bio_iostat_ctx *iostat_ctx,
d95bf22a4d1cbe Daeho Jeong 2021-08-20  184  				int rw, bool is_sync)
d95bf22a4d1cbe Daeho Jeong 2021-08-20  185  {
d95bf22a4d1cbe Daeho Jeong 2021-08-20  186  	unsigned long ts_diff;
d95bf22a4d1cbe Daeho Jeong 2021-08-20  187  	unsigned int iotype = iostat_ctx->type;
d95bf22a4d1cbe Daeho Jeong 2021-08-20  188  	unsigned long flags;
d95bf22a4d1cbe Daeho Jeong 2021-08-20  189  	struct f2fs_sb_info *sbi = iostat_ctx->sbi;
d95bf22a4d1cbe Daeho Jeong 2021-08-20  190  	struct iostat_lat_info *io_lat = sbi->iostat_io_lat;
d95bf22a4d1cbe Daeho Jeong 2021-08-20  191  	int idx;
d95bf22a4d1cbe Daeho Jeong 2021-08-20  192  
d95bf22a4d1cbe Daeho Jeong 2021-08-20  193  	if (!sbi->iostat_enable)
d95bf22a4d1cbe Daeho Jeong 2021-08-20  194  		return;
d95bf22a4d1cbe Daeho Jeong 2021-08-20  195  
d95bf22a4d1cbe Daeho Jeong 2021-08-20  196  	ts_diff = jiffies - iostat_ctx->submit_ts;
d95bf22a4d1cbe Daeho Jeong 2021-08-20  197  	if (iotype >= META_FLUSH)
d95bf22a4d1cbe Daeho Jeong 2021-08-20  198  		iotype = META;
d95bf22a4d1cbe Daeho Jeong 2021-08-20  199  
d95bf22a4d1cbe Daeho Jeong 2021-08-20  200  	if (rw == 0) {
d95bf22a4d1cbe Daeho Jeong 2021-08-20  201  		idx = READ_IO;
d95bf22a4d1cbe Daeho Jeong 2021-08-20  202  	} else {
d95bf22a4d1cbe Daeho Jeong 2021-08-20  203  		if (is_sync)
d95bf22a4d1cbe Daeho Jeong 2021-08-20  204  			idx = WRITE_SYNC_IO;
d95bf22a4d1cbe Daeho Jeong 2021-08-20  205  		else
d95bf22a4d1cbe Daeho Jeong 2021-08-20  206  			idx = WRITE_ASYNC_IO;
d95bf22a4d1cbe Daeho Jeong 2021-08-20  207  	}
d95bf22a4d1cbe Daeho Jeong 2021-08-20  208  
d95bf22a4d1cbe Daeho Jeong 2021-08-20  209  	spin_lock_irqsave(&sbi->iostat_lat_lock, flags);
d95bf22a4d1cbe Daeho Jeong 2021-08-20 @210  	io_lat->sum_lat[idx][iotype] += ts_diff;
d95bf22a4d1cbe Daeho Jeong 2021-08-20 @211  	io_lat->bio_cnt[idx][iotype]++;
d95bf22a4d1cbe Daeho Jeong 2021-08-20 @212  	if (ts_diff > io_lat->peak_lat[idx][iotype])
d95bf22a4d1cbe Daeho Jeong 2021-08-20  213  		io_lat->peak_lat[idx][iotype] = ts_diff;
d95bf22a4d1cbe Daeho Jeong 2021-08-20  214  	spin_unlock_irqrestore(&sbi->iostat_lat_lock, flags);
d95bf22a4d1cbe Daeho Jeong 2021-08-20  215  }
d95bf22a4d1cbe Daeho Jeong 2021-08-20  216  

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