1# probe libc's inet_pton & backtrace it with ping 2 3# Installs a probe on libc's inet_pton function, that will use uprobes, 4# then use 'perf trace' on a ping to localhost asking for just one packet 5# with the a backtrace 3 levels deep, check that it is what we expect. 6# This needs no debuginfo package, all is done using the libc ELF symtab 7# and the CFI info in the binaries. 8 9# Arnaldo Carvalho de Melo <acme@kernel.org>, 2017 10 11. $(dirname $0)/lib/probe.sh 12 13libc=$(grep -w libc /proc/self/maps | head -1 | sed -r 's/.*[[:space:]](\/.*)/\1/g') 14nm -g $libc 2>/dev/null | fgrep -q inet_pton || exit 254 15 16trace_libc_inet_pton_backtrace() { 17 idx=0 18 expected[0]="ping[][0-9 \.:]+probe_libc:inet_pton: \([[:xdigit:]]+\)" 19 expected[1]=".*inet_pton[[:space:]]\($libc\)$" 20 case "$(uname -m)" in 21 s390x) 22 eventattr='call-graph=dwarf' 23 expected[2]="gaih_inet.*[[:space:]]\($libc|inlined\)$" 24 expected[3]="__GI_getaddrinfo[[:space:]]\($libc|inlined\)$" 25 expected[4]="main[[:space:]]\(.*/bin/ping.*\)$" 26 expected[5]="__libc_start_main[[:space:]]\($libc\)$" 27 expected[6]="_start[[:space:]]\(.*/bin/ping.*\)$" 28 ;; 29 *) 30 eventattr='max-stack=3' 31 expected[2]="getaddrinfo[[:space:]]\($libc\)$" 32 expected[3]=".*\(.*/bin/ping.*\)$" 33 ;; 34 esac 35 36 file=`mktemp -u /tmp/perf.data.XXX` 37 38 perf record -e probe_libc:inet_pton/$eventattr/ -o $file ping -6 -c 1 ::1 > /dev/null 2>&1 39 perf script -i $file | while read line ; do 40 echo $line 41 echo "$line" | egrep -q "${expected[$idx]}" 42 if [ $? -ne 0 ] ; then 43 printf "FAIL: expected backtrace entry %d \"%s\" got \"%s\"\n" $idx "${expected[$idx]}" "$line" 44 exit 1 45 fi 46 let idx+=1 47 [ -z "${expected[$idx]}" ] && break 48 done 49 50 rm -f $file 51} 52 53# Check for IPv6 interface existence 54ip a sh lo | fgrep -q inet6 || exit 2 55 56skip_if_no_perf_probe && \ 57perf probe -q $libc inet_pton && \ 58trace_libc_inet_pton_backtrace 59err=$? 60rm -f ${file} 61perf probe -q -d probe_libc:inet_pton 62exit $err 63