scripts/check-execstack.awk

   1 # This awk script expects to get command-line files that are each
   2 # the output of 'readelf -l' on a single shared object.
   3 # But the first file should contain just "execstack-no" or "execstack-yes",
   4 # indicating what the default is in the absence of PT_GNU_STACK.
   5 # It exits successfully (0) if none indicated executable stack.
   6 # It fails (1) if any did indicate executable stack.
   7 # It fails (2) if the input did not take the expected form.
   8
   9 BEGIN {
  10   result = sanity = 0; default_exec = -1;
  11   split(xfail, xfails, " ");
  12   for (x in xfails)
  13     expected_fails[xfails[x] ".phdr"] = 1;
  14 }
  15
  16 /^execstack-no$/ { default_exec = 0; next }
  17 /^execstack-yes$/ { default_exec = 1; next }
  18
  19 function check_one(name) {
  20   if (default_exec == -1) {
  21     print "*** missing execstack-default file?";
  22     result = 2;
  23   }
  24
  25   n = split(name, parts, "/");
  26   basename = parts[n];
  27   expected_fail = basename in expected_fails;
  28
  29   if (!sanity) {
  30     print name ": *** input did not look like readelf -l output";
  31     result = 2;
  32   } else if (stack_line) {
  33     if (stack_line ~ /^.*RW .*$/) {
  34       print name ": OK";
  35     } else if (stack_line ~ /^.*E.*$/) {
  36       if (expected_fail) {
  37         print name ": *** executable stack signaled, expected";
  38       } else {
  39         print name ": *** executable stack signaled";
  40         result = result ? result : 1;
  41       }
  42     }
  43   } else if (default_exec) {
  44     if (expected_fail) {
  45       print name ": *** no PT_GNU_STACK entry, expected";
  46     } else {
  47       print name ": *** no PT_GNU_STACK entry";
  48       result = result ? result : 1;
  49     }
  50   } else {
  51     print name ": no PT_GNU_STACK but default is OK";
  52   }
  53
  54   sanity = 0;
  55 }
  56
  57 FILENAME != lastfile {
  58   if (lastfile)
  59     check_one(lastfile);
  60   lastfile = FILENAME;
  61 }
  62
  63 $1 == "Type" && $7 == "Flg" { sanity = 1; stack_line = "" }
  64 $1 == "GNU_STACK" { stack_line = $0 }
  65
  66 END {
  67   check_one(lastfile);
  68   exit(result);
  69 }