tests/tail-2/inotify-hash-abuse.sh

   1 #!/bin/sh
   2 # Exercise an abort-inducing flaw in inotify-enabled tail -F.
   3
   4 # Copyright (C) 2009-2017 Free Software Foundation, Inc.
   5
   6 # This program is free software: you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation, either version 3 of the License, or
   9 # (at your option) any later version.
  10
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
  20 print_ver_ tail
  21
  22 # 9 is a magic number, related to internal details of tail.c and hash.c
  23 n=9
  24 seq $n | xargs touch || framework_failure_
  25
  26 check_tail_output()
  27 {
  28   local delay="$1"
  29   grep "$tail_re" out > /dev/null ||
  30     { sleep $delay; return 1; }
  31 }
  32
  33 # Terminate any background tail process
  34 cleanup_() { kill $pid 2>/dev/null && wait $pid; }
  35
  36 # Speedup the non inotify case
  37 fastpoll='-s.1 --max-unchanged-stats=1'
  38
  39 for mode in '' '---disable-inotify'; do
  40   rm -f out
  41
  42   tail $mode $fastpoll -qF $(seq $n) > out 2>&1 & pid=$!
  43
  44   # Wait up to 12.7s for tail to start
  45   echo x > $n
  46   tail_re='^x$' retry_delay_ check_tail_output .1 7 ||
  47     { cat out; fail=1; }
  48
  49   mv 1 f || framework_failure_
  50
  51   # Wait 12.7s for this diagnostic:
  52   # tail: '1' has become inaccessible: No such file or directory
  53   tail_re='inaccessible' retry_delay_ check_tail_output .1 7 ||
  54     { cat out; fail=1; }
  55
  56   # Trigger the bug.  Before the fix, this would provoke the abort.
  57   echo a > 1 || framework_failure_
  58
  59   # Wait up to 6.3s for the "tail: '1' has appeared; ..." message
  60   # (or for the buggy tail to die)
  61   tail_re='has appeared' retry_delay_ check_tail_output .1 6 ||
  62     { cat out; fail=1; }
  63
  64   # Double check that tail hasn't aborted
  65   kill -0 $pid || fail=1
  66
  67   cleanup_
  68 done
  69
  70
  71 Exit $fail