This patch allows us to skip tests that require PTRACE_ATTACH in situations
where PTRACE_ATTACH is only allowed when CAP_SYS_PTRACE is held (i.e., for
root, by default.)

Reported at <https://bugzilla.redhat.com/show_bug.cgi?id=1210966>.

--- elfutils-0.161/tests/run-deleted.sh	2015-04-11 16:38:33.028556235 +0200
+++ elfutils-0.161/tests/run-deleted.sh	2015-04-11 16:46:15.012442185 +0200
@@ -17,6 +17,15 @@
 
 . $srcdir/backtrace-subr.sh
 
+# Check whether the Yama policy allows us to use PTRACE_ATTACH.
+if [ -f /proc/sys/kernel/yama/ptrace_scope ]
+then
+    if [ `cat /proc/sys/kernel/yama/ptrace_scope` -ne 0 ]
+    then
+	exit 77
+    fi
+fi
+
 tempfiles deleted deleted-lib.so
 cp -p ${abs_builddir}/deleted ${abs_builddir}/deleted-lib.so .
 
--- elfutils-0.161/tests/vdsosyms.c	2015-04-11 16:40:20.633461110 +0200
+++ elfutils-0.161/tests/vdsosyms.c	2015-04-11 16:45:06.611866677 +0200
@@ -23,6 +23,8 @@
 #include <stdio.h>
 #include <string.h>
 #include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
 #include <unistd.h>
 #include ELFUTILS_HEADER(dwfl)
 
@@ -68,6 +70,7 @@ module_callback (Dwfl_Module *mod, void
 int
 main (int argc __attribute__ ((unused)), char **argv __attribute__ ((unused)))
 {
+  static const char ptrace_scope_file[] = "/proc/sys/kernel/yama/ptrace_scope";
   static char *debuginfo_path;
   static const Dwfl_Callbacks proc_callbacks =
     {
@@ -76,6 +79,20 @@ main (int argc __attribute__ ((unused)),
 
       .find_elf = dwfl_linux_proc_find_elf,
     };
+
+  /* Check whether the Yama policy allows us to use PTRACE_ATTACH.  */
+  int ptrace_scope = open (ptrace_scope_file, O_RDONLY);
+  if (ptrace_scope >= 0)
+    {
+      char buf[10];
+      int count = read (ptrace_scope, buf, sizeof buf);
+      assert (count > 0);
+      if (buf[0] != '0')
+	/* We're not allowed, so skip this test.  */
+	return 77;
+      close (ptrace_scope);
+    }
+
   Dwfl *dwfl = dwfl_begin (&proc_callbacks);
   if (dwfl == NULL)
     error (2, 0, "dwfl_begin: %s", dwfl_errmsg (-1));