record+probe_libc_inet_pton.sh (3115B)
1#!/bin/sh 2# probe libc's inet_pton & backtrace it with ping 3 4# Installs a probe on libc's inet_pton function, that will use uprobes, 5# then use 'perf trace' on a ping to localhost asking for just one packet 6# with the a backtrace 3 levels deep, check that it is what we expect. 7# This needs no debuginfo package, all is done using the libc ELF symtab 8# and the CFI info in the binaries. 9 10# SPDX-License-Identifier: GPL-2.0 11# Arnaldo Carvalho de Melo <acme@kernel.org>, 2017 12 13. $(dirname $0)/lib/probe.sh 14 15libc=$(grep -w libc /proc/self/maps | head -1 | sed -r 's/.*[[:space:]](\/.*)/\1/g') 16nm -Dg $libc 2>/dev/null | fgrep -q inet_pton || exit 254 17 18event_pattern='probe_libc:inet_pton(\_[[:digit:]]+)?' 19 20add_libc_inet_pton_event() { 21 22 event_name=$(perf probe -f -x $libc -a inet_pton 2>&1 | tail -n +2 | head -n -5 | \ 23 grep -P -o "$event_pattern(?=[[:space:]]\(on inet_pton in $libc\))") 24 25 if [ $? -ne 0 -o -z "$event_name" ] ; then 26 printf "FAIL: could not add event\n" 27 return 1 28 fi 29} 30 31trace_libc_inet_pton_backtrace() { 32 33 expected=`mktemp -u /tmp/expected.XXX` 34 35 echo "ping[][0-9 \.:]+$event_name: \([[:xdigit:]]+\)" > $expected 36 echo ".*inet_pton\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected 37 case "$(uname -m)" in 38 s390x) 39 eventattr='call-graph=dwarf,max-stack=4' 40 echo "gaih_inet.*\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected 41 echo "(__GI_)?getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected 42 echo "main\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$" >> $expected 43 ;; 44 ppc64|ppc64le) 45 eventattr='max-stack=4' 46 echo "gaih_inet.*\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected 47 echo "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected 48 echo ".*(\+0x[[:xdigit:]]+|\[unknown\])[[:space:]]\(.*/bin/ping.*\)$" >> $expected 49 ;; 50 *) 51 eventattr='max-stack=3' 52 echo "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected 53 echo ".*(\+0x[[:xdigit:]]+|\[unknown\])[[:space:]]\(.*/bin/ping.*\)$" >> $expected 54 ;; 55 esac 56 57 perf_data=`mktemp -u /tmp/perf.data.XXX` 58 perf_script=`mktemp -u /tmp/perf.script.XXX` 59 perf record -e $event_name/$eventattr/ -o $perf_data ping -6 -c 1 ::1 > /dev/null 2>&1 60 perf script -i $perf_data > $perf_script 61 62 exec 3<$perf_script 63 exec 4<$expected 64 while read line <&3 && read -r pattern <&4; do 65 [ -z "$pattern" ] && break 66 echo $line 67 echo "$line" | egrep -q "$pattern" 68 if [ $? -ne 0 ] ; then 69 printf "FAIL: expected backtrace entry \"%s\" got \"%s\"\n" "$pattern" "$line" 70 return 1 71 fi 72 done 73 74 # If any statements are executed from this point onwards, 75 # the exit code of the last among these will be reflected 76 # in err below. If the exit code is 0, the test will pass 77 # even if the perf script output does not match. 78} 79 80delete_libc_inet_pton_event() { 81 82 if [ -n "$event_name" ] ; then 83 perf probe -q -d $event_name 84 fi 85} 86 87# Check for IPv6 interface existence 88ip a sh lo | fgrep -q inet6 || exit 2 89 90skip_if_no_perf_probe && \ 91add_libc_inet_pton_event && \ 92trace_libc_inet_pton_backtrace 93err=$? 94rm -f ${perf_data} ${perf_script} ${expected} 95delete_libc_inet_pton_event 96exit $err