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 "$0")/lib/probe.sh" 14. "$(dirname "$0")/lib/probe_vfs_getname.sh" 15 16libc=$(grep -w libc /proc/self/maps | head -1 | sed -r 's/.*[[:space:]](\/.*)/\1/g') 17nm -Dg $libc 2>/dev/null | grep -F -q inet_pton || exit 254 18 19event_pattern='probe_libc:inet_pton(\_[[:digit:]]+)?' 20 21add_libc_inet_pton_event() { 22 23 event_name=$(perf probe -f -x $libc -a inet_pton 2>&1 | tail -n +2 | head -n -5 | \ 24 grep -P -o "$event_pattern(?=[[:space:]]\(on inet_pton in $libc\))") 25 26 if [ $? -ne 0 ] || [ -z "$event_name" ] ; then 27 printf "FAIL: could not add event\n" 28 return 1 29 fi 30} 31 32trace_libc_inet_pton_backtrace() { 33 34 expected=`mktemp -u /tmp/expected.XXX` 35 36 echo "ping[][0-9 \.:]+$event_name: \([[:xdigit:]]+\)" > $expected 37 echo ".*inet_pton\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected 38 case "$(uname -m)" in 39 s390x) 40 eventattr='call-graph=dwarf,max-stack=4' 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 ".*(\+0x[[:xdigit:]]+|\[unknown\])[[:space:]]\(.*/bin/ping.*\)$" >> $expected 53 ;; 54 esac 55 56 perf_data=`mktemp -u /tmp/perf.data.XXX` 57 perf_script=`mktemp -u /tmp/perf.script.XXX` 58 59 # Check presence of libtraceevent support to run perf record 60 skip_no_probe_record_support "$event_name/$eventattr/" 61 [ $? -eq 2 ] && return 2 62 63 perf record -e $event_name/$eventattr/ -o $perf_data ping -6 -c 1 ::1 > /dev/null 2>&1 64 # check if perf data file got created in above step. 65 if [ ! -e $perf_data ]; then 66 printf "FAIL: perf record failed to create \"%s\" \n" "$perf_data" 67 return 1 68 fi 69 perf script -i $perf_data | tac | grep -m1 ^ping -B9 | tac > $perf_script 70 71 exec 3<$perf_script 72 exec 4<$expected 73 while read line <&3 && read -r pattern <&4; do 74 [ -z "$pattern" ] && break 75 echo $line 76 echo "$line" | grep -E -q "$pattern" 77 if [ $? -ne 0 ] ; then 78 printf "FAIL: expected backtrace entry \"%s\" got \"%s\"\n" "$pattern" "$line" 79 return 1 80 fi 81 done 82 83 # If any statements are executed from this point onwards, 84 # the exit code of the last among these will be reflected 85 # in err below. If the exit code is 0, the test will pass 86 # even if the perf script output does not match. 87} 88 89delete_libc_inet_pton_event() { 90 91 if [ -n "$event_name" ] ; then 92 perf probe -q -d $event_name 93 fi 94} 95 96# Check for IPv6 interface existence 97ip a sh lo | grep -F -q inet6 || exit 2 98 99skip_if_no_perf_probe && \ 100add_libc_inet_pton_event && \ 101trace_libc_inet_pton_backtrace 102err=$? 103rm -f ${perf_data} ${perf_script} ${expected} 104delete_libc_inet_pton_event 105exit $err 106