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# shellcheck source=lib/probe.sh 14. "$(dirname "$0")/lib/probe.sh" 15# shellcheck source=lib/probe_vfs_getname.sh 16. "$(dirname "$0")/lib/probe_vfs_getname.sh" 17 18libc=$(grep -w libc /proc/self/maps | head -1 | sed -r 's/.*[[:space:]](\/.*)/\1/g') 19nm -Dg $libc 2>/dev/null | grep -F -q inet_pton || exit 254 20 21event_pattern='probe_libc:inet_pton(\_[[:digit:]]+)?' 22 23add_libc_inet_pton_event() { 24 25 event_name=$(perf probe -f -x $libc -a inet_pton 2>&1 | tail -n +2 | head -n -5 | \ 26 grep -P -o "$event_pattern(?=[[:space:]]\(on inet_pton in $libc\))") 27 28 if [ $? -ne 0 ] || [ -z "$event_name" ] ; then 29 printf "FAIL: could not add event\n" 30 return 1 31 fi 32} 33 34trace_libc_inet_pton_backtrace() { 35 36 expected=`mktemp -u /tmp/expected.XXX` 37 38 echo "ping[][0-9 \.:]+$event_name: \([[:xdigit:]]+\)" > $expected 39 echo ".*inet_pton\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected 40 case "$(uname -m)" in 41 s390x) 42 eventattr='call-graph=dwarf,max-stack=4' 43 echo "(__GI_)?getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected 44 echo "main\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$" >> $expected 45 ;; 46 ppc64|ppc64le) 47 eventattr='max-stack=4' 48 echo "gaih_inet.*\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected 49 echo "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected 50 echo ".*(\+0x[[:xdigit:]]+|\[unknown\])[[:space:]]\(.*/bin/ping.*\)$" >> $expected 51 ;; 52 *) 53 eventattr='max-stack=3' 54 echo ".*(\+0x[[:xdigit:]]+|\[unknown\])[[:space:]]\(.*/bin/ping.*\)$" >> $expected 55 ;; 56 esac 57 58 perf_data=`mktemp -u /tmp/perf.data.XXX` 59 perf_script=`mktemp -u /tmp/perf.script.XXX` 60 61 # Check presence of libtraceevent support to run perf record 62 skip_no_probe_record_support "$event_name/$eventattr/" 63 [ $? -eq 2 ] && return 2 64 65 perf record -e $event_name/$eventattr/ -o $perf_data ping -6 -c 1 ::1 > /dev/null 2>&1 66 # check if perf data file got created in above step. 67 if [ ! -e $perf_data ]; then 68 printf "FAIL: perf record failed to create \"%s\" \n" "$perf_data" 69 return 1 70 fi 71 perf script -i $perf_data | tac | grep -m1 ^ping -B9 | tac > $perf_script 72 73 exec 3<$perf_script 74 exec 4<$expected 75 while read line <&3 && read -r pattern <&4; do 76 [ -z "$pattern" ] && break 77 echo $line 78 echo "$line" | grep -E -q "$pattern" 79 if [ $? -ne 0 ] ; then 80 printf "FAIL: expected backtrace entry \"%s\" got \"%s\"\n" "$pattern" "$line" 81 return 1 82 fi 83 done 84 85 # If any statements are executed from this point onwards, 86 # the exit code of the last among these will be reflected 87 # in err below. If the exit code is 0, the test will pass 88 # even if the perf script output does not match. 89} 90 91delete_libc_inet_pton_event() { 92 93 if [ -n "$event_name" ] ; then 94 perf probe -q -d $event_name 95 fi 96} 97 98# Check for IPv6 interface existence 99ip a sh lo | grep -F -q inet6 || exit 2 100 101skip_if_no_perf_probe && \ 102add_libc_inet_pton_event && \ 103trace_libc_inet_pton_backtrace 104err=$? 105rm -f ${perf_data} ${perf_script} ${expected} 106delete_libc_inet_pton_event 107exit $err 108