1 # probe libc's inet_pton & backtrace it with ping
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.
9 # Arnaldo Carvalho de Melo <acme@kernel.org>, 2017
11 . $(dirname $0)/lib/probe.sh
13 ld=$(realpath /lib64/ld*.so.* | uniq)
14 libc=$(echo $ld | sed 's/ld/libc/g')
16 trace_libc_inet_pton_backtrace() {
18 expected[0]="PING.*bytes"
19 expected[1]="64 bytes from ::1.*"
20 expected[2]=".*ping statistics.*"
21 expected[3]=".*packets transmitted.*"
22 expected[4]="rtt min.*"
23 expected[5]="[0-9]+\.[0-9]+[[:space:]]+probe_libc:inet_pton:\([[:xdigit:]]+\)"
24 expected[6]=".*inet_pton[[:space:]]\($libc|inlined\)$"
27 eventattr='call-graph=dwarf'
28 expected[7]="gaih_inet.*[[:space:]]\($libc|inlined\)$"
29 expected[8]="__GI_getaddrinfo[[:space:]]\($libc|inlined\)$"
30 expected[9]="main[[:space:]]\(.*/bin/ping.*\)$"
31 expected[10]="__libc_start_main[[:space:]]\($libc\)$"
32 expected[11]="_start[[:space:]]\(.*/bin/ping.*\)$"
35 eventattr='max-stack=3'
36 expected[7]="getaddrinfo[[:space:]]\($libc\)$"
37 expected[8]=".*\(.*/bin/ping.*\)$"
41 perf trace --no-syscalls -e probe_libc:inet_pton/$eventattr/ ping -6 -c 1 ::1 2>&1 | grep -v ^$ | while read line ; do
43 echo "$line" | egrep -q "${expected[$idx]}"
44 if [ $? -ne 0 ] ; then
45 printf "FAIL: expected backtrace entry %d \"%s\" got \"%s\"\n" $idx "${expected[$idx]}" "$line"
49 [ -z "${expected[$idx]}" ] && break
53 skip_if_no_perf_probe && \
54 perf probe -q $libc inet_pton && \
55 trace_libc_inet_pton_backtrace
58 perf probe -q -d probe_libc:inet_pton