gdb/SOURCES/gdb-rhbz1842691-corefile-mem-access-11of15.patch

From FEDORA_PATCHES Mon Sep 17 00:00:00 2001
From: Keith Seitz <keiths@redhat.com>
Date: Tue, 28 Jul 2020 09:26:44 -0400
Subject: gdb-rhbz1842691-corefile-mem-access-11of15.patch

;; Adjust coredump-filter.exp to account for NT_FILE note handling
;; Kevin Buettner, RH BZ 1842961

   Author: Kevin Buettner <kevinb@redhat.com>
   Date:   Fri Jul 3 20:10:22 2020 -0700

    Adjust coredump-filter.exp to account for NT_FILE note handling

    This commit makes adjustments to coredump-filter.exp to account
    for the fact that NT_FILE file-backed mappings are now available
    when a core file is loaded.  Thus, a test which was expected
    to PASS when a memory region was determined to be unavailable
    (due to no file-backed mappings being available) will now FAIL
    due to those mappings being available from having loaded the
    NT_FILE note.

    I had originally marked the test as XFAIL, but Mihails Strasuns
    suggested a much better approach:

        1) First test that it still works if file is accessible in the
           filesystem.
        2) Temporarily move / rename the file and test that disassembly
           doesn't work anymore.

    That's what this commit implements.

    gdb/testsuite/ChangeLog:

    	* gdb.base/coredump-filter.exp: Add second
    	non-Private-Shared-Anon-File test.
    	(test_disasm): Rename binfile for test which is expected
    	to fail.

diff --git a/gdb/testsuite/gdb.base/coredump-filter.exp b/gdb/testsuite/gdb.base/coredump-filter.exp
--- a/gdb/testsuite/gdb.base/coredump-filter.exp
+++ b/gdb/testsuite/gdb.base/coredump-filter.exp
@@ -80,15 +80,26 @@ proc do_load_and_test_core { core var working_var working_value dump_excluded }
 # disassemble of a function (i.e., the binary's .text section).  GDB
 # should fail in this case.  However, it must succeed if the binary is
 # provided along with the corefile.  This is what we test here.
+#
+# A further complication is that Linux NT_FILE notes are now read from
+# the corefile.  This note allows GDB to find the binary for file
+# backed mappings even though the binary wasn't loaded by GDB in the
+# conventional manner.  In order to see the expected failure for this
+# case, we rename the binary in order to perform this test.
 
 proc test_disasm { core address should_fail } {
-    global testfile hex
+    global testfile hex binfile
 
     # Restart GDB without loading the binary.
     with_test_prefix "no binary" {
 	gdb_exit
 	gdb_start
 
+	set hide_binfile [standard_output_file "${testfile}.hide"]
+	if { $should_fail == 1 } {
+	    remote_exec host "mv -f $binfile $hide_binfile"
+	}
+
 	set core_loaded [gdb_core_cmd "$core" "load core"]
 	if { $core_loaded == -1 } {
 	    fail "loading $core"
@@ -96,6 +107,7 @@ proc test_disasm { core address should_fail } {
 	}
 
 	if { $should_fail == 1 } {
+	    remote_exec host "mv -f $hide_binfile $binfile"
 	    gdb_test "x/i \$pc" "=> $hex:\tCannot access memory at address $hex" \
 		"disassemble function with corefile and without a binary"
 	} else {
@@ -225,5 +237,9 @@ foreach item $all_anon_corefiles {
 }
 
 with_test_prefix "loading and testing corefile for non-Private-Shared-Anon-File" {
+    test_disasm $non_private_shared_anon_file_core $main_addr 0
+}
+
+with_test_prefix "loading and testing corefile for non-Private-Shared-Anon-File with renamed binary" {
     test_disasm $non_private_shared_anon_file_core $main_addr 1
 }