11 files changed, 111 insertions, 1 deletions
diff --git a/lldb/tools/debugserver/source/DNB.cpp b/lldb/tools/debugserver/source/DNB.cpp
index 268b30b195d..e9461221954 100644
--- a/lldb/tools/debugserver/source/DNB.cpp
+++ b/lldb/tools/debugserver/source/DNB.cpp
@@ -1124,6 +1124,34 @@ DNBProcessMemoryDeallocate (nub_process_t pid, nub_addr_t addr)
     return 0;
 }
 
+//----------------------------------------------------------------------
+// Try to determine if a given address in the process PID is in an 
+// executable region or not.  Used for sniffing potential caller addresses 
+// when unwinding a stack and we're making guesses about where the caller 
+// frame addr might be saved.
+//
+// RETURNS:  1 if executable
+//           0 if not executable
+//          -1 if we cannot make a determination on this target
+//
+// Note that unmapped memory (an address that is not an allocated page in
+// PID) will return as 0 - it is not executable memory.  -1 is intended
+// for a platform where we can't inspect memory region attributes.
+//----------------------------------------------------------------------
+int
+DNBIsAddressExecutable (nub_process_t pid, nub_addr_t addr)
+{
+    MachProcessSP procSP;
+    if (GetProcessSP (pid, procSP))
+    {
+        if (procSP->IsAddressExecutable(addr))
+            return 1;
+        else
+            return 0;
+    }
+    return -1;
+}
+
 
 //----------------------------------------------------------------------
 // Formatted output that uses memory and registers from process and
diff --git a/lldb/tools/debugserver/source/DNB.h b/lldb/tools/debugserver/source/DNB.h
index e9a3f341d19..6c3cd9bbb70 100644
--- a/lldb/tools/debugserver/source/DNB.h
+++ b/lldb/tools/debugserver/source/DNB.h
@@ -66,6 +66,7 @@ nub_size_t      DNBProcessMemoryRead    (nub_process_t pid, nub_addr_t addr, nub
 nub_size_t      DNBProcessMemoryWrite   (nub_process_t pid, nub_addr_t addr, nub_size_t size, const void *buf) DNB_EXPORT;
 nub_addr_t      DNBProcessMemoryAllocate (nub_process_t pid, nub_size_t size, uint32_t permissions) DNB_EXPORT;
 nub_bool_t      DNBProcessMemoryDeallocate (nub_process_t pid, nub_addr_t addr) DNB_EXPORT;
+int             DNBIsAddressExecutable (nub_process_t pid, nub_addr_t addr) ;
 //----------------------------------------------------------------------
 // Process status
 //----------------------------------------------------------------------
diff --git a/lldb/tools/debugserver/source/MacOSX/MachProcess.cpp b/lldb/tools/debugserver/source/MacOSX/MachProcess.cpp
index a256acec8d3..133f41e2df1 100644
--- a/lldb/tools/debugserver/source/MacOSX/MachProcess.cpp
+++ b/lldb/tools/debugserver/source/MacOSX/MachProcess.cpp
@@ -478,7 +478,6 @@ MachProcess::Detach()
     return true;
 }
 
-
 nub_size_t
 MachProcess::RemoveTrapsFromBuffer (nub_addr_t addr, nub_size_t size, uint8_t *buf) const
 {
@@ -604,6 +603,11 @@ MachProcess::WriteMemory (nub_addr_t addr, nub_size_t size, const void *buf)
     return bytes_written;
 }
 
+bool
+MachProcess::IsAddressExecutable(nub_addr_t address)
+{
+    return m_task.IsAddressExecutable (address);
+}
 
 void
 MachProcess::ReplyToAllExceptions ()
diff --git a/lldb/tools/debugserver/source/MacOSX/MachProcess.h b/lldb/tools/debugserver/source/MacOSX/MachProcess.h
index d52735adba7..b68fa7f49e2 100644
--- a/lldb/tools/debugserver/source/MacOSX/MachProcess.h
+++ b/lldb/tools/debugserver/source/MacOSX/MachProcess.h
@@ -99,6 +99,7 @@ public:
     bool                    Detach ();
     nub_size_t              ReadMemory (nub_addr_t addr, nub_size_t size, void *buf);
     nub_size_t              WriteMemory (nub_addr_t addr, nub_size_t size, const void *buf);
+    bool                    IsAddressExecutable(nub_addr_t address);
 
     //----------------------------------------------------------------------
     // Path and arg accessors
diff --git a/lldb/tools/debugserver/source/MacOSX/MachTask.cpp b/lldb/tools/debugserver/source/MacOSX/MachTask.cpp
index 862a96b9367..035198e4864 100644
--- a/lldb/tools/debugserver/source/MacOSX/MachTask.cpp
+++ b/lldb/tools/debugserver/source/MacOSX/MachTask.cpp
@@ -205,6 +205,23 @@ MachTask::WriteMemory (nub_addr_t addr, nub_size_t size, const void *buf)
 }
 
 //----------------------------------------------------------------------
+// MachTask::IsAddressExecutable
+//----------------------------------------------------------------------
+bool
+MachTask::IsAddressExecutable (nub_addr_t addr)
+{
+    task_t task = TaskPort();
+    bool ret = false;
+    if (task != TASK_NULL)
+    {
+        ret = m_vm_memory.IsExecutable(task, addr);
+        DNBLogThreadedIf(LOG_MEMORY, "MachTask::IsAddressExecutable ( addr = 0x%8.8llx ) => %s", (uint64_t)addr, (ret ? "true" : "false"));
+    }
+    return ret;
+}
+
+
+//----------------------------------------------------------------------
 // MachTask::TaskPortForProcessID
 //----------------------------------------------------------------------
 task_t
diff --git a/lldb/tools/debugserver/source/MacOSX/MachTask.h b/lldb/tools/debugserver/source/MacOSX/MachTask.h
index 0e74086a727..da64ba6c997 100644
--- a/lldb/tools/debugserver/source/MacOSX/MachTask.h
+++ b/lldb/tools/debugserver/source/MacOSX/MachTask.h
@@ -64,6 +64,7 @@ public:
 
             nub_size_t      ReadMemory (nub_addr_t addr, nub_size_t size, void *buf);
             nub_size_t      WriteMemory (nub_addr_t addr, nub_size_t size, const void *buf);
+            bool            IsAddressExecutable (nub_addr_t addr) ;
 
             nub_addr_t      AllocateMemory (nub_size_t size, uint32_t permissions);
             nub_bool_t      DeallocateMemory (nub_addr_t addr);
diff --git a/lldb/tools/debugserver/source/MacOSX/MachVMMemory.cpp b/lldb/tools/debugserver/source/MacOSX/MachVMMemory.cpp
index eb7e10746e2..58789ed191a 100644
--- a/lldb/tools/debugserver/source/MacOSX/MachVMMemory.cpp
+++ b/lldb/tools/debugserver/source/MacOSX/MachVMMemory.cpp
@@ -52,6 +52,17 @@ MachVMMemory::MaxBytesLeftInPage(nub_addr_t addr, nub_size_t count)
     return count;
 }
 
+bool
+MachVMMemory::IsExecutable(task_t task, nub_addr_t address)
+{
+    MachVMRegion vmRegion(task);
+
+    if (vmRegion.GetRegionForAddress(address) && vmRegion.IsExecutable())
+       return true;
+    else
+       return false;
+}
+
 nub_size_t
 MachVMMemory::Read(task_t task, nub_addr_t address, void *data, nub_size_t data_count)
 {
diff --git a/lldb/tools/debugserver/source/MacOSX/MachVMMemory.h b/lldb/tools/debugserver/source/MacOSX/MachVMMemory.h
index 5635186854a..421e4b4999c 100644
--- a/lldb/tools/debugserver/source/MacOSX/MachVMMemory.h
+++ b/lldb/tools/debugserver/source/MacOSX/MachVMMemory.h
@@ -27,6 +27,7 @@ public:
     nub_size_t Read(task_t task, nub_addr_t address, void *data, nub_size_t data_count);
     nub_size_t Write(task_t task, nub_addr_t address, const void *data, nub_size_t data_count);
     nub_size_t PageSize();
+    bool       IsExecutable(task_t task, nub_addr_t address);
 
 protected:
     nub_size_t MaxBytesLeftInPage(nub_addr_t addr, nub_size_t count);
diff --git a/lldb/tools/debugserver/source/MacOSX/MachVMRegion.h b/lldb/tools/debugserver/source/MacOSX/MachVMRegion.h
index 617e221a57e..bd1aaa0e2a2 100644
--- a/lldb/tools/debugserver/source/MacOSX/MachVMRegion.h
+++ b/lldb/tools/debugserver/source/MacOSX/MachVMRegion.h
@@ -42,6 +42,9 @@ public:
     bool SetProtections(mach_vm_address_t addr, mach_vm_size_t size, vm_prot_t prot);
     bool RestoreProtections();
     bool GetRegionForAddress(nub_addr_t addr);
+
+    bool IsExecutable() const { return (m_data.protection & VM_PROT_EXECUTE) == VM_PROT_EXECUTE; }
+
 protected:
 #if defined (VM_REGION_SUBMAP_SHORT_INFO_COUNT_64)
     typedef vm_region_submap_short_info_data_64_t RegionInfo;
diff --git a/lldb/tools/debugserver/source/RNBRemote.cpp b/lldb/tools/debugserver/source/RNBRemote.cpp
index 2b265ed70fd..75c85a7ba05 100644
--- a/lldb/tools/debugserver/source/RNBRemote.cpp
+++ b/lldb/tools/debugserver/source/RNBRemote.cpp
@@ -186,6 +186,8 @@ RNBRemote::CreatePacketTable  ()
 //  t.push_back (Packet (pass_signals_to_inferior,      &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "QPassSignals:", "Specify which signals are passed to the inferior"));
     t.push_back (Packet (allocate_memory,               &RNBRemote::HandlePacket_AllocateMemory, NULL, "_M", "Allocate memory in the inferior process."));
     t.push_back (Packet (deallocate_memory,             &RNBRemote::HandlePacket_DeallocateMemory, NULL, "_m", "Deallocate memory in the inferior process."));
+    t.push_back (Packet (address_is_executable,         &RNBRemote::HandlePacket_IsAddressExecutable, NULL, "QAddressIsExecutable", "Indicate if an address is in an executable region or not"));
+
 }
 
 
@@ -3238,6 +3240,45 @@ RNBRemote::HandlePacket_c (const char *p)
     return rnb_success;
 }
 
+rnb_err_t
+RNBRemote::HandlePacket_IsAddressExecutable (const char *p)
+{
+    /* This tells us whether the specified address is in an executable region
+       in the remote process or not.  Examples of use:
+          QAddressIsExecutable,3a55140
+          AddressIsInExecutableRegion
+
+          QAddressIsExecutable,0
+          AddressIsNotInExecutableRegion
+
+          QAddressIsExecutable,3a551140   (on a different platform)
+          CannotDetermineRegionAttributes
+    */
+
+    p += sizeof ("QAddressIsExecutable") - 1;
+    if (*p == '\0')
+       return SendPacket ("OK");
+    if (*p++ != ',')
+       return SendPacket ("E67");
+    if (*p == '0' && (*(p + 1) == 'x' || *(p + 1) == 'X'))
+       p += 2;
+
+    errno = 0;
+    uint64_t address = strtoul (p, NULL, 16);
+    if (errno != 0 && address == 0)
+    {
+        return HandlePacket_ILLFORMED (__FILE__, __LINE__, p, "Invalid address in QAddressIsExecutable packet");
+    }
+    int ret = DNBIsAddressExecutable (m_ctx.ProcessID(), address);
+    if (ret == 1)
+        return SendPacket ("AddressIsInExecutableRegion");
+    if (ret == 0)
+        return SendPacket ("AddressIsNotInExecutableRegion");
+    
+    return SendPacket ("CannotDetermineRegionAttributes");
+}
+
+
 /* `C sig [;addr]'
  Resume with signal sig, optionally at address addr.  */
 
diff --git a/lldb/tools/debugserver/source/RNBRemote.h b/lldb/tools/debugserver/source/RNBRemote.h
index 6940efc15b3..573846cad9b 100644
--- a/lldb/tools/debugserver/source/RNBRemote.h
+++ b/lldb/tools/debugserver/source/RNBRemote.h
@@ -106,6 +106,7 @@ public:
         set_stdout,                     // 'QSetSTDOUT:'
         set_stderr,                     // 'QSetSTDERR:'
         set_working_dir,                // 'QSetWorkingDir:'
+        address_is_executable,          // 'QAddressIsExecutable'
         allocate_memory,                // '_M'
         deallocate_memory,              // '_m'
 
@@ -198,6 +199,7 @@ public:
     rnb_err_t HandlePacket_ILLFORMED (const char *file, int line, const char *p, const char *description);
     rnb_err_t HandlePacket_AllocateMemory (const char *p);
     rnb_err_t HandlePacket_DeallocateMemory (const char *p);
+    rnb_err_t HandlePacket_IsAddressExecutable (const char *p);
 
     rnb_err_t HandlePacket_stop_process (const char *p);