| #!/bin/sh |
| # probe libc's inet_pton & backtrace it with ping |
| |
| # Installs a probe on libc's inet_pton function, that will use uprobes, |
| # then use 'perf trace' on a ping to localhost asking for just one packet |
| # with the a backtrace 3 levels deep, check that it is what we expect. |
| # This needs no debuginfo package, all is done using the libc ELF symtab |
| # and the CFI info in the binaries. |
| |
| # SPDX-License-Identifier: GPL-2.0 |
| # Arnaldo Carvalho de Melo <acme@kernel.org>, 2017 |
| |
| # shellcheck source=lib/probe.sh |
| . "$(dirname "$0")/lib/probe.sh" |
| # shellcheck source=lib/probe_vfs_getname.sh |
| . "$(dirname "$0")/lib/probe_vfs_getname.sh" |
| |
| libc=$(grep -w libc /proc/self/maps | head -1 | sed -r 's/.*[[:space:]](\/.*)/\1/g') |
| nm -Dg $libc 2>/dev/null | grep -F -q inet_pton || exit 254 |
| |
| event_pattern='probe_libc:inet_pton(\_[[:digit:]]+)?' |
| |
| add_libc_inet_pton_event() { |
| |
| event_name=$(perf probe -f -x $libc -a inet_pton 2>&1 | tail -n +2 | head -n -5 | \ |
| grep -P -o "$event_pattern(?=[[:space:]]\(on inet_pton in $libc\))") |
| |
| if [ $? -ne 0 ] || [ -z "$event_name" ] ; then |
| printf "FAIL: could not add event\n" |
| return 1 |
| fi |
| } |
| |
| trace_libc_inet_pton_backtrace() { |
| |
| expected=`mktemp -u /tmp/expected.XXX` |
| |
| echo "ping[][0-9 \.:]+$event_name: \([[:xdigit:]]+\)" > $expected |
| echo ".*inet_pton\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected |
| case "$(uname -m)" in |
| s390x) |
| eventattr='call-graph=dwarf,max-stack=4' |
| echo "(__GI_)?getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected |
| echo "main\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$" >> $expected |
| ;; |
| ppc64|ppc64le) |
| eventattr='max-stack=4' |
| # Add gaih_inet to expected backtrace only if it is part of libc. |
| if nm $libc | grep -F -q gaih_inet.; then |
| echo "gaih_inet.*\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected |
| fi |
| echo "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected |
| echo ".*(\+0x[[:xdigit:]]+|\[unknown\])[[:space:]]\(.*/bin/ping.*\)$" >> $expected |
| ;; |
| *) |
| eventattr='max-stack=3' |
| echo ".*(\+0x[[:xdigit:]]+|\[unknown\])[[:space:]]\(.*/bin/ping.*\)$" >> $expected |
| ;; |
| esac |
| |
| perf_data=`mktemp -u /tmp/perf.data.XXX` |
| perf_script=`mktemp -u /tmp/perf.script.XXX` |
| |
| # Check presence of libtraceevent support to run perf record |
| skip_no_probe_record_support "$event_name/$eventattr/" |
| [ $? -eq 2 ] && return 2 |
| |
| perf record -e $event_name/$eventattr/ -o $perf_data ping -6 -c 1 ::1 > /dev/null 2>&1 |
| # check if perf data file got created in above step. |
| if [ ! -e $perf_data ]; then |
| printf "FAIL: perf record failed to create \"%s\" \n" "$perf_data" |
| return 1 |
| fi |
| perf script -i $perf_data | tac | grep -m1 ^ping -B9 | tac > $perf_script |
| |
| exec 3<$perf_script |
| exec 4<$expected |
| while read line <&3 && read -r pattern <&4; do |
| [ -z "$pattern" ] && break |
| echo $line |
| echo "$line" | grep -E -q "$pattern" |
| if [ $? -ne 0 ] ; then |
| printf "FAIL: expected backtrace entry \"%s\" got \"%s\"\n" "$pattern" "$line" |
| return 1 |
| fi |
| done |
| |
| # If any statements are executed from this point onwards, |
| # the exit code of the last among these will be reflected |
| # in err below. If the exit code is 0, the test will pass |
| # even if the perf script output does not match. |
| } |
| |
| delete_libc_inet_pton_event() { |
| |
| if [ -n "$event_name" ] ; then |
| perf probe -q -d $event_name |
| fi |
| } |
| |
| # Check for IPv6 interface existence |
| ip a sh lo | grep -F -q inet6 || exit 2 |
| |
| skip_if_no_perf_probe && \ |
| add_libc_inet_pton_event && \ |
| trace_libc_inet_pton_backtrace |
| err=$? |
| rm -f ${perf_data} ${perf_script} ${expected} |
| delete_libc_inet_pton_event |
| exit $err |