[Lldb-commits] [lldb] r260367 - Use BKPT instead of UDF for arm/thumb breakpoints

[Tamas Berghammer via lldb-commits]

Author: tberghammer
Date: Wed Feb 10 04:42:00 2016
New Revision: 260367

URL: http://llvm.org/viewvc/llvm-project?rev=260367&view=rev
Log:
Use BKPT instead of UDF for arm/thumb breakpoints

The UDF instruction is deprecated in armv7 and in case of thumb2
instructions set it don't work well together with the IT instruction.

Differential revision: http://reviews.llvm.org/D16853

Modified:
    lldb/trunk/source/Plugins/Platform/Linux/PlatformLinux.cpp
    lldb/trunk/source/Plugins/Process/Linux/NativeProcessLinux.cpp

Modified: lldb/trunk/source/Plugins/Platform/Linux/PlatformLinux.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Platform/Linux/PlatformLinux.cpp?rev=260367&r1=260366&r2=260367&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Platform/Linux/PlatformLinux.cpp (original)
+++ lldb/trunk/source/Plugins/Platform/Linux/PlatformLinux.cpp Wed Feb 10 04:42:00 2016
@@ -560,10 +560,8 @@ PlatformLinux::GetSoftwareBreakpointTrap
         break;
     case llvm::Triple::arm:
         {
-            // The ARM reference recommends the use of 0xe7fddefe and 0xdefe
-            // but the linux kernel does otherwise.
-            static const uint8_t g_arm_breakpoint_opcode[] = { 0xf0, 0x01, 0xf0, 0xe7 };
-            static const uint8_t g_thumb_breakpoint_opcode[] = { 0x01, 0xde };
+            static const uint8_t g_arm_breakpoint_opcode[] = { 0x70, 0xbe, 0x20, 0xe1 };
+            static const uint8_t g_thumb_breakpoint_opcode[] = { 0x70, 0xbe };
 
             lldb::BreakpointLocationSP bp_loc_sp (bp_site->GetOwnerAtIndex (0));
             AddressClass addr_class = eAddressClassUnknown;

Modified: lldb/trunk/source/Plugins/Process/Linux/NativeProcessLinux.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/Linux/NativeProcessLinux.cpp?rev=260367&r1=260366&r2=260367&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Process/Linux/NativeProcessLinux.cpp (original)
+++ lldb/trunk/source/Plugins/Process/Linux/NativeProcessLinux.cpp Wed Feb 10 04:42:00 2016
@@ -1294,8 +1294,10 @@ NativeProcessLinux::MonitorSIGTRAP(const
             break;
         }
 
-        // Otherwise, report step over
-        MonitorTrace(thread);
+        if (m_arch.GetMachine() == llvm::Triple::arm)
+            MonitorBreakpoint(thread); // Arm linux reports trace for breakpoint hits
+        else
+            MonitorTrace(thread); // Report the trace
         break;
     }
 
@@ -2289,13 +2291,11 @@ NativeProcessLinux::GetSoftwareBreakpoin
     // FIXME put this behind a breakpoint protocol class that can be set per
     // architecture.  Need MIPS support here.
     static const uint8_t g_aarch64_opcode[] = { 0x00, 0x00, 0x20, 0xd4 };
-    // The ARM reference recommends the use of 0xe7fddefe and 0xdefe but the
-    // linux kernel does otherwise.
-    static const uint8_t g_arm_breakpoint_opcode[] = { 0xf0, 0x01, 0xf0, 0xe7 };
+    static const uint8_t g_arm_breakpoint_opcode[] = { 0x70, 0xbe, 0x20, 0xe1 };
     static const uint8_t g_i386_opcode [] = { 0xCC };
     static const uint8_t g_mips64_opcode[] = { 0x00, 0x00, 0x00, 0x0d };
     static const uint8_t g_mips64el_opcode[] = { 0x0d, 0x00, 0x00, 0x00 };
-    static const uint8_t g_thumb_breakpoint_opcode[] = { 0x01, 0xde };
+    static const uint8_t g_thumb_breakpoint_opcode[] = { 0x70, 0xbe };
 
     switch (m_arch.GetMachine ())
     {