[LLDB] OpenBSD support

Summary:
Add basic OpenBSD support. This is enough to be able to analyze core dumps for OpenBSD/amd64, OpenBSD/arm, OpenBSD/arm64 and OpenBSD/i386.

Note that part of the changes to source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp fix a bug that probably affects other platforms as well.  The GetProgramHeaderByIndex() interface use 1-based indices, but in some case when looping over the headers the, the loop starts at 0 and misses the last header.  This caused problems on OpenBSD since OpenBSD core dumps have the PT_NOTE segment as the last program header.


Reviewers: joerg, labath, krytarowski

Reviewed By: krytarowski

Subscribers: aemerson, emaste, rengolin, srhines, krytarowski, mgorny, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D31131

llvm-svn: 298810

2 files changed, 56 insertions, 0 deletions

diff --git a/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp b/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp
index 99c1b7d3733..6bbe91488c3 100644
--- a/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp
+++ b/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp
@@ -431,6 +431,10 @@ enum {
   NT_FILE = 0x46494c45,
   NT_PRXFPREG = 0x46e62b7f,
   NT_SIGINFO = 0x53494749,
+  NT_OPENBSD_PROCINFO = 10,
+  NT_OPENBSD_AUXV = 11,
+  NT_OPENBSD_REGS = 20,
+  NT_OPENBSD_FPREGS = 21,
 };
 
 namespace FREEBSD {
@@ -481,6 +485,18 @@ static void ParseFreeBSDThrMisc(ThreadData &thread_data, DataExtractor &data) {
   thread_data.name = data.GetCStr(&offset, 20);
 }
 
+static void ParseOpenBSDProcInfo(ThreadData &thread_data, DataExtractor &data)
+{
+  lldb::offset_t offset = 0;
+  
+  int version = data.GetU32(&offset);
+  if (version != 1)
+	  return;
+
+  offset += 4;
+  thread_data.signo = data.GetU32(&offset);
+}
+
 /// Parse Thread context from PT_NOTE segment and store it in the thread list
 /// Notes:
 /// 1) A PT_NOTE segment is composed of one or more NOTE entries.
@@ -569,6 +585,24 @@ Error ProcessElfCore::ParseThreadContextsFromNoteSegment(
       default:
         break;
       }
+    } else if (note.n_name.substr(0, 7) == "OpenBSD") {
+      // OpenBSD per-thread information is stored in notes named
+      // "OpenBSD@nnn" so match on the initial part of the string.
+      m_os = llvm::Triple::OpenBSD;
+      switch (note.n_type) {
+      case NT_OPENBSD_PROCINFO:
+	ParseOpenBSDProcInfo(*thread_data, note_data);
+	break;
+      case NT_OPENBSD_AUXV:
+	m_auxv = DataExtractor(note_data);
+	break;
+      case NT_OPENBSD_REGS:
+	thread_data->gpregset = note_data;
+	break;
+      case NT_OPENBSD_FPREGS:
+	thread_data->fpregset = note_data;
+	break;
+      }
     } else if (note.n_name == "CORE") {
       switch (note.n_type) {
       case NT_PRSTATUS:
diff --git a/lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp b/lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp
index c82af86b936..f7f4653b545 100644
--- a/lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp
+++ b/lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp
@@ -21,6 +21,8 @@
 #include "Plugins/Process/Utility/RegisterContextLinux_i386.h"
 #include "Plugins/Process/Utility/RegisterContextLinux_s390x.h"
 #include "Plugins/Process/Utility/RegisterContextLinux_x86_64.h"
+#include "Plugins/Process/Utility/RegisterContextOpenBSD_i386.h"
+#include "Plugins/Process/Utility/RegisterContextOpenBSD_x86_64.h"
 #include "Plugins/Process/Utility/RegisterInfoPOSIX_arm.h"
 #include "Plugins/Process/Utility/RegisterInfoPOSIX_arm64.h"
 #include "ProcessElfCore.h"
@@ -133,6 +135,26 @@ ThreadElfCore::CreateRegisterContextForFrame(StackFrame *frame) {
       break;
     }
 
+    case llvm::Triple::OpenBSD: {
+      switch (arch.GetMachine()) {
+      case llvm::Triple::aarch64:
+        reg_interface = new RegisterInfoPOSIX_arm64(arch);
+        break;
+      case llvm::Triple::arm:
+        reg_interface = new RegisterInfoPOSIX_arm(arch);
+        break;
+      case llvm::Triple::x86:
+	reg_interface = new RegisterContextOpenBSD_i386(arch);
+	break;
+      case llvm::Triple::x86_64:
+        reg_interface = new RegisterContextOpenBSD_x86_64(arch);
+        break;
+      default:
+        break;
+      }
+      break;
+    }
+
     default:
       break;
     }