| # 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. |
| |
| # Arnaldo Carvalho de Melo <acme@kernel.org>, 2017 |
| |
| . $(dirname $0)/lib/probe.sh |
| |
| ld=$(realpath /lib64/ld*.so.* | uniq) |
| libc=$(echo $ld | sed 's/ld/libc/g') |
| |
| trace_libc_inet_pton_backtrace() { |
| idx=0 |
| expected[0]="PING.*bytes" |
| expected[1]="64 bytes from ::1.*" |
| expected[2]=".*ping statistics.*" |
| expected[3]=".*packets transmitted.*" |
| expected[4]="rtt min.*" |
| expected[5]="[0-9]+\.[0-9]+[[:space:]]+probe_libc:inet_pton:\([[:xdigit:]]+\)" |
| expected[6]=".*inet_pton[[:space:]]\($libc|inlined\)$" |
| case "$(uname -m)" in |
| s390x) |
| eventattr='call-graph=dwarf' |
| expected[7]="gaih_inet.*[[:space:]]\($libc|inlined\)$" |
| expected[8]="__GI_getaddrinfo[[:space:]]\($libc|inlined\)$" |
| expected[9]="main[[:space:]]\(.*/bin/ping.*\)$" |
| expected[10]="__libc_start_main[[:space:]]\($libc\)$" |
| expected[11]="_start[[:space:]]\(.*/bin/ping.*\)$" |
| ;; |
| *) |
| eventattr='max-stack=3' |
| expected[7]="getaddrinfo[[:space:]]\($libc\)$" |
| expected[8]=".*\(.*/bin/ping.*\)$" |
| ;; |
| esac |
| |
| perf trace --no-syscalls -e probe_libc:inet_pton/$eventattr/ ping -6 -c 1 ::1 2>&1 | grep -v ^$ | while read line ; do |
| echo $line |
| echo "$line" | egrep -q "${expected[$idx]}" |
| if [ $? -ne 0 ] ; then |
| printf "FAIL: expected backtrace entry %d \"%s\" got \"%s\"\n" $idx "${expected[$idx]}" "$line" |
| exit 1 |
| fi |
| let idx+=1 |
| [ -z "${expected[$idx]}" ] && break |
| done |
| } |
| |
| skip_if_no_perf_probe && \ |
| perf probe -q $libc inet_pton && \ |
| trace_libc_inet_pton_backtrace |
| err=$? |
| rm -f ${file} |
| perf probe -q -d probe_libc:inet_pton |
| exit $err |