[Lldb-commits] [lldb] r299239 - Verify memory address range validity in GDBRemoteCommunicationClient

[Stephane Sezer via lldb-commits]

Author: sas
Date: Fri Mar 31 13:00:48 2017
New Revision: 299239

URL: http://llvm.org/viewvc/llvm-project?rev=299239&view=rev
Log:
Verify memory address range validity in GDBRemoteCommunicationClient

Summary:
This aims to verify the validity of the response from the debugging
server in GDBRemoteCommunicationClient::GetMemoryRegionInfo. I was
working with ds2 (https://github.com/facebook/ds2) and encountered a bug
that caused the server's response to have a 'size' value of 0, which
caused lldb to behave incorrectly.

Reviewers: k8stone, labath, clayborg

Reviewed By: labath, clayborg

Subscribers: clayborg, sas, lldb-commits

Differential Revision: https://reviews.llvm.org/D31485

Change by Alex Langford <apl at fb.com>

Modified:
    lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
    lldb/trunk/unittests/Process/gdb-remote/GDBRemoteCommunicationClientTest.cpp

Modified: lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp?rev=299239&r1=299238&r2=299239&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp (original)
+++ lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp Fri Mar 31 13:00:48 2017
@@ -1503,13 +1503,18 @@ Error GDBRemoteCommunicationClient::GetM
         }
       }
 
-      // We got a valid address range back but no permissions -- which means
-      // this is an unmapped page
-      if (region_info.GetRange().IsValid() && saw_permissions == false) {
-        region_info.SetReadable(MemoryRegionInfo::eNo);
-        region_info.SetWritable(MemoryRegionInfo::eNo);
-        region_info.SetExecutable(MemoryRegionInfo::eNo);
-        region_info.SetMapped(MemoryRegionInfo::eNo);
+      if (region_info.GetRange().IsValid()) {
+        // We got a valid address range back but no permissions -- which means
+        // this is an unmapped page
+        if (!saw_permissions) {
+          region_info.SetReadable(MemoryRegionInfo::eNo);
+          region_info.SetWritable(MemoryRegionInfo::eNo);
+          region_info.SetExecutable(MemoryRegionInfo::eNo);
+          region_info.SetMapped(MemoryRegionInfo::eNo);
+        }
+      } else {
+        // We got an invalid address range back
+        error.SetErrorString("Server returned invalid range");
       }
     } else {
       m_supports_memory_region_info = eLazyBoolNo;

Modified: lldb/trunk/unittests/Process/gdb-remote/GDBRemoteCommunicationClientTest.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/unittests/Process/gdb-remote/GDBRemoteCommunicationClientTest.cpp?rev=299239&r1=299238&r2=299239&view=diff
==============================================================================
--- lldb/trunk/unittests/Process/gdb-remote/GDBRemoteCommunicationClientTest.cpp (original)
+++ lldb/trunk/unittests/Process/gdb-remote/GDBRemoteCommunicationClientTest.cpp Fri Mar 31 13:00:48 2017
@@ -13,6 +13,7 @@
 #include "Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h"
 #include "lldb/Core/ModuleSpec.h"
 #include "lldb/Core/StructuredData.h"
+#include "lldb/Target/MemoryRegionInfo.h"
 #include "lldb/Utility/DataBuffer.h"
 
 #include "llvm/ADT/ArrayRef.h"
@@ -331,3 +332,41 @@ TEST_F(GDBRemoteCommunicationClientTest,
   HandlePacket(server, "QPassSignals:", "OK");
   EXPECT_TRUE(result.get().Success());
 }
+
+TEST_F(GDBRemoteCommunicationClientTest, GetMemoryRegionInfo) {
+  TestClient client;
+  MockServer server;
+  Connect(client, server);
+  if (HasFailure())
+    return;
+
+  const lldb::addr_t addr = 0xa000;
+  MemoryRegionInfo region_info;
+  std::future<Error> result = std::async(std::launch::async, [&] {
+    return client.GetMemoryRegionInfo(addr, region_info);
+  });
+
+  // name is: /foo/bar.so
+  HandlePacket(server,
+      "qMemoryRegionInfo:a000",
+      "start:a000;size:2000;permissions:rx;name:2f666f6f2f6261722e736f;");
+  EXPECT_TRUE(result.get().Success());
+
+}
+
+TEST_F(GDBRemoteCommunicationClientTest, GetMemoryRegionInfoInvalidResponse) {
+  TestClient client;
+  MockServer server;
+  Connect(client, server);
+  if (HasFailure())
+    return;
+
+  const lldb::addr_t addr = 0x4000;
+  MemoryRegionInfo region_info;
+  std::future<Error> result = std::async(std::launch::async, [&] {
+    return client.GetMemoryRegionInfo(addr, region_info);
+  });
+
+  HandlePacket(server, "qMemoryRegionInfo:4000", "start:4000;size:0000;");
+  EXPECT_FALSE(result.get().Success());
+}