tools/perf/tests/shell/record+probe_libc_inet_pton.sh

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