From FEDORA_PATCHES Mon Sep 17 00:00:00 2001

From: Keith Seitz <keiths@redhat.com>

Date: Mon, 27 Jul 2020 17:27:39 -0400

Subject: gdb-rhbz1842691-corefile-mem-access-5of15.patch

;; Test ability to access unwritten-to mmap data in core file

;; Kevin Buettner, RH BZ 1842961

   Author: Kevin Buettner <kevinb@redhat.com>

   Date:   Wed Mar 4 17:42:43 2020 -0700

    Test ability to access unwritten-to mmap data in core file

    gdb/testsuite/ChangeLog:

    	PR corefiles/25631

    	* gdb.base/corefile.exp (accessing anonymous, unwritten-to mmap data):

    	New test.

    	* gdb.base/coremaker.c (buf3): New global.

    	(mmapdata): Add mmap call which uses MAP_ANONYMOUS and MAP_PRIVATE

    	flags.

diff --git a/gdb/testsuite/gdb.base/corefile.exp b/gdb/testsuite/gdb.base/corefile.exp

--- a/gdb/testsuite/gdb.base/corefile.exp

+++ b/gdb/testsuite/gdb.base/corefile.exp

@@ -175,6 +175,15 @@ gdb_test_multiple "x/8bd buf2" "$test" {

     }

 }

+# Test ability to read anonymous and, more importantly, unwritten-to

+# mmap'd data.

+

+if { ![istarget *-linux*] } {

+    setup_xfail "*-*-*"

+}

+gdb_test "x/wx buf3" "$hex:\[ \t\]+0x00000000" \

+	 "accessing anonymous, unwritten-to mmap data"

+

 # test reinit_frame_cache

 gdb_load ${binfile}

diff --git a/gdb/testsuite/gdb.base/coremaker.c b/gdb/testsuite/gdb.base/coremaker.c

--- a/gdb/testsuite/gdb.base/coremaker.c

+++ b/gdb/testsuite/gdb.base/coremaker.c

@@ -38,6 +38,7 @@

 char *buf1;

 char *buf2;

+char *buf3;

 int coremaker_data = 1;	/* In Data section */

 int coremaker_bss;	/* In BSS section */

@@ -104,6 +105,15 @@ mmapdata ()

     }

   /* Touch buf2 so kernel writes it out into 'core'. */

   buf2[0] = buf1[0];

+

+  /* Create yet another region which is allocated, but not written to.  */

+  buf3 = mmap (NULL, MAPSIZE, PROT_READ | PROT_WRITE,

+               MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);

+  if (buf3 == (char *) -1)

+    {

+      perror ("mmap failed");

+      return;

+    }

 }

 void