1 files changed, 22 insertions, 46 deletions

diff --git a/lldb/source/Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.cpp b/lldb/source/Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.cpp
index 6ac210acf6d..4c2b02f376e 100644
--- a/lldb/source/Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.cpp
+++ b/lldb/source/Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.cpp
@@ -254,37 +254,29 @@ DynamicLoaderDarwinKernel::SearchForKernelWithDebugHints (Process *process)
 
     Error read_err;
     addr_t addr = LLDB_INVALID_ADDRESS;
-    if (process->GetTarget().GetArchitecture().GetAddressByteSize() == 8)
+    addr_t kernel_addresses_64[] = { 0xffffff8000002010ULL, 0xffffff8000004010ULL, 
+                                     0xfffffff000002010ULL, 0xfffffff000004010ULL, 
+                                     LLDB_INVALID_ADDRESS };
+    addr_t kernel_addresses_32[] = { 0xffff0110,
+                                     LLDB_INVALID_ADDRESS };
+    for (size_t i = 0; kernel_addresses_64[i] != LLDB_INVALID_ADDRESS; i++)
     {
-        addr = process->ReadUnsignedIntegerFromMemory (0xffffff8000002010ULL, 8, LLDB_INVALID_ADDRESS, read_err);
-        if (CheckForKernelImageAtAddress (addr, process).IsValid())
-        {
-            return addr;
-        }
-        addr = process->ReadUnsignedIntegerFromMemory (0xffffff8000004010ULL, 8, LLDB_INVALID_ADDRESS, read_err);
-        if (CheckForKernelImageAtAddress (addr, process).IsValid())
-        {
-            return addr;
-        }
-        addr = process->ReadUnsignedIntegerFromMemory (0xfffffff000002010ULL, 8, LLDB_INVALID_ADDRESS, read_err);
-        if (CheckForKernelImageAtAddress (addr, process).IsValid())
-        {
-            return addr;
-        }
-        addr = process->ReadUnsignedIntegerFromMemory (0xfffffff000004010ULL, 8, LLDB_INVALID_ADDRESS, read_err);
+        addr = process->ReadUnsignedIntegerFromMemory (kernel_addresses_64[i], 8, LLDB_INVALID_ADDRESS, read_err);
         if (CheckForKernelImageAtAddress (addr, process).IsValid())
         {
             return addr;
         }
     }
-    else
+
+    for (size_t i = 0; kernel_addresses_32[i] != LLDB_INVALID_ADDRESS; i++)
     {
-        addr = process->ReadUnsignedIntegerFromMemory (0xffff0110, 4, LLDB_INVALID_ADDRESS, read_err);
+        addr = process->ReadUnsignedIntegerFromMemory (kernel_addresses_32[i], 4, LLDB_INVALID_ADDRESS, read_err);
         if (CheckForKernelImageAtAddress (addr, process).IsValid())
         {
             return addr;
         }
     }
+
     return LLDB_INVALID_ADDRESS;
 }
 
@@ -311,28 +303,14 @@ DynamicLoaderDarwinKernel::SearchForKernelNearPC (Process *process)
     if (pc == LLDB_INVALID_ADDRESS)
         return LLDB_INVALID_ADDRESS;
 
-    addr_t kernel_range_low;
-    if (process->GetTarget().GetArchitecture().GetAddressByteSize() == 8)
-    {
-        kernel_range_low = 1ULL << 63;
-    }
-    else
-    {
-        kernel_range_low = 1ULL << 31;
-    }
-
-    // Outside the normal kernel address range, this is probably userland code running right now
-    if (pc < kernel_range_low)
-        return LLDB_INVALID_ADDRESS;
-
     // The kernel will load at at one megabyte boundary (0x100000), or at that boundary plus 
-    // an offset of one page (0x1000) or two, depending on the device.
+    // an offset of one page (0x1000) or two, or four (0x4000), depending on the device.
 
     // Round the current pc down to the nearest one megabyte boundary - the place where we will start searching.
     addr_t addr = pc & ~0xfffff;
 
-    int i = 0;
-    while (i < 32 && pc >= kernel_range_low)
+    // Search backwards 32 megabytes, looking for the start of the kernel at each one-megabyte boundary.
+    for (int i = 0; i < 32; i++, addr -= 0x100000)
     {
         if (CheckForKernelImageAtAddress (addr, process).IsValid())
             return addr;
@@ -342,8 +320,6 @@ DynamicLoaderDarwinKernel::SearchForKernelNearPC (Process *process)
             return addr + 0x2000;
         if (CheckForKernelImageAtAddress (addr + 0x4000, process).IsValid())
             return addr + 0x4000;
-        i++;
-        addr -= 0x100000;
     }
 
     return LLDB_INVALID_ADDRESS;
@@ -429,19 +405,19 @@ DynamicLoaderDarwinKernel::CheckForKernelImageAtAddress (lldb::addr_t addr, Proc
 
     // Read the mach header and see whether it looks like a kernel
     llvm::MachO::mach_header header;
-    if (process->DoReadMemory (addr, &header, sizeof(header), read_error) != sizeof(header))
+    if (process->DoReadMemory (addr, &header, sizeof (header), read_error) != sizeof (header))
         return UUID();
 
     if (header.magic == llvm::MachO::MH_CIGAM ||
         header.magic == llvm::MachO::MH_CIGAM_64)
     {
-        header.magic        = llvm::ByteSwap_32(header.magic);
-        header.cputype      = llvm::ByteSwap_32(header.cputype);
-        header.cpusubtype   = llvm::ByteSwap_32(header.cpusubtype);
-        header.filetype     = llvm::ByteSwap_32(header.filetype);
-        header.ncmds        = llvm::ByteSwap_32(header.ncmds);
-        header.sizeofcmds   = llvm::ByteSwap_32(header.sizeofcmds);
-        header.flags        = llvm::ByteSwap_32(header.flags);
+        header.magic        = llvm::ByteSwap_32 (header.magic);
+        header.cputype      = llvm::ByteSwap_32 (header.cputype);
+        header.cpusubtype   = llvm::ByteSwap_32 (header.cpusubtype);
+        header.filetype     = llvm::ByteSwap_32 (header.filetype);
+        header.ncmds        = llvm::ByteSwap_32 (header.ncmds);
+        header.sizeofcmds   = llvm::ByteSwap_32 (header.sizeofcmds);
+        header.flags        = llvm::ByteSwap_32 (header.flags);
     }
 
     // A kernel is an executable which does not have the dynamic link object flag set.