> On Oct 31, 2020, at 4:27 AM, David Laight <David.Laight@xxxxxxxxxx> wrote: > > From: Song Liu >> Sent: 30 October 2020 23:55 >> >> Making perf with gcc-9.1.1 generates the following warning: >> >> CC ui/browsers/hists.o >> ui/browsers/hists.c: In function 'perf_evsel__hists_browse': >> ui/browsers/hists.c:3078:61: error: '%d' directive output may be \ >> truncated writing between 1 and 11 bytes into a region of size \ >> between 2 and 12 [-Werror=format-truncation=] >> >> 3078 | "Max event group index to sort is %d (index from 0 to %d)", >> | ^~ >> ui/browsers/hists.c:3078:7: note: directive argument in the range [-2147483648, 8] >> 3078 | "Max event group index to sort is %d (index from 0 to %d)", >> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> In file included from /usr/include/stdio.h:937, >> from ui/browsers/hists.c:5: >> >> IOW, the string in line 3078 might be too long for buf[] of 64 bytes. >> >> Fix this by increasing the size of buf[] to 128. > > ISTM that something should be unsigned so that the bound check > that puts an upper bound of 8 implies a lower bound. > > David Changing both "%d" in this line to "%u" does fix the warning. But we are printing "evsel->core.nr_members - 1" here, and nr_members is signed int. So I feel more comfortable keep the "%d"s and increase the buffer size. Thanks, Song
