gdb-rhbz1007614-memleak-infpy_read_memory-test.patch

;; Fix 'memory leak in infpy_read_memory()' (RH BZ 1007614)
;;=fedoratest

Original message by Tom Tromey:

  <https://sourceware.org/ml/gdb-patches/2012-03/msg00955.html>
  Message-ID: <[email protected]>

Comment from Sergio Durigan Junior:

  In order to correctly test this patch, I wrote a testcase based on Jan
  Kratochvil's <gdb/testsuite/gdb.base/gcore-excessive-memory.exp>.  The
  testcase, which can be seen below, tests GDB in order to see if the
  amount of memory being leaked is minimal, as requested in the bugzilla.
  It is hard to define what "minimum" is, so I ran the testcase on all
  supported RHEL architectures and came up with an average.

commit cc0265c
Author: Tom Tromey <[email protected]>
Date:   Wed Mar 28 17:38:08 2012 +0000

    	* python/py-inferior.c (infpy_read_memory): Remove cleanups and
    	explicitly free 'buffer' on exit paths.  Decref 'membuf_object'
    	before returning.

Author: ivanivanov884

gdb/testsuite/gdb.python/py-gdb-rhbz1007614-memleak-infpy_read_memory.c

@@ -0,0 +1,27 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2014 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+static struct x
+  {
+    char unsigned u[4096];
+  } x, *px = &x;
+
+int
+main (int argc, char *argv[])
+{
+  return 0;
+}

gdb/testsuite/gdb.python/py-gdb-rhbz1007614-memleak-infpy_read_memory.exp

@@ -0,0 +1,68 @@
+# Copyright 2014 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+set testfile py-gdb-rhbz1007614-memleak-infpy_read_memory
+set srcfile ${testfile}.c
+set binfile [standard_output_file ${testfile}]
+
+if { [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile}] } {
+    return -1
+}
+
+if { [skip_python_tests] } { continue }
+
+set pid_of_gdb [exp_pid -i [board_info host fileid]]
+
+proc memory_v_pages_get {} {
+    global pid_of_gdb
+    set fd [open "/proc/$pid_of_gdb/statm"]
+    gets $fd line
+    close $fd
+    # number of pages of virtual memory
+    scan $line "%d" drs
+    return $drs
+}
+
+if { ![runto_main] } {
+    untested $testfile.exp
+    return -1
+}
+
+set remote_python_file [remote_download host ${srcdir}/${subdir}/${testfile}.py]
+
+gdb_test "source ${remote_python_file}" ""
+
+gdb_test "hello-world" ""
+
+set kbytes_before [memory_v_pages_get]
+verbose -log "kbytes_before = $kbytes_before"
+
+gdb_test "hello-world" ""
+
+set kbytes_after [memory_v_pages_get]
+verbose -log "kbytes_after = $kbytes_after"
+
+set kbytes_diff [expr $kbytes_after - $kbytes_before]
+verbose -log "kbytes_diff = $kbytes_diff"
+
+# The value "1000" was calculated by running a few GDB sessions with this
+# testcase, and seeing how much (in average) the memory consumption
+# increased after the "hello-world" command issued above.  The average
+# was around 500 bytes, so I chose 1000 as a high estimate.
+if { $kbytes_diff > 1000 } {
+    fail "there is a memory leak on GDB (RHBZ 1007614)"
+} else {
+    pass "there is not a memory leak on GDB (RHBZ 1007614)"
+}

gdb/testsuite/gdb.python/py-gdb-rhbz1007614-memleak-infpy_read_memory.py

@@ -0,0 +1,30 @@
+# Copyright (C) 2014 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+class HelloWorld (gdb.Command):
+    """Greet the whole world."""
+
+    def __init__ (self):
+        super (HelloWorld, self).__init__ ("hello-world",
+                                           gdb.COMMAND_OBSCURE)
+
+    def invoke (self, arg, from_tty):
+        px = gdb.parse_and_eval("px")
+        core = gdb.inferiors()[0]
+        for i in range(256 * 1024):
+            chunk = core.read_memory(px, 4096)
+        print "Hello, World!"
+
+HelloWorld ()