Always return a valid answer for qMemoryRegionInfo if the packet is supported.

We will return a valid range when possible and omit the "permissions" key
when the memory is not readable, writeable or executeable. This will help us
know the difference between an error back from this packet and unsupported,
from just "this address isn't in a valid region".

llvm-svn: 146394

7 files changed, 90 insertions, 98 deletions

diff --git a/lldb/tools/debugserver/source/DNB.cpp b/lldb/tools/debugserver/source/DNB.cpp
index 12950102edd..f60c26fab6d 100644
--- a/lldb/tools/debugserver/source/DNB.cpp
+++ b/lldb/tools/debugserver/source/DNB.cpp
@@ -1139,7 +1139,7 @@ DNBProcessMemoryDeallocate (nub_process_t pid, nub_addr_t addr)
 //
 //----------------------------------------------------------------------
 int
-DNBMemoryRegionInfo (nub_process_t pid, nub_addr_t addr, DNBRegionInfo *region_info)
+DNBProcessMemoryRegionInfo (nub_process_t pid, nub_addr_t addr, DNBRegionInfo *region_info)
 {
     MachProcessSP procSP;
     if (GetProcessSP (pid, procSP))
diff --git a/lldb/tools/debugserver/source/DNB.h b/lldb/tools/debugserver/source/DNB.h
index 2e791f41e21..1f612a6605b 100644
--- a/lldb/tools/debugserver/source/DNB.h
+++ b/lldb/tools/debugserver/source/DNB.h
@@ -64,9 +64,9 @@ nub_bool_t      DNBProcessSignal        (nub_process_t pid, int signal) DNB_EXPO
 nub_bool_t      DNBProcessKill          (nub_process_t pid) DNB_EXPORT;
 nub_size_t      DNBProcessMemoryRead    (nub_process_t pid, nub_addr_t addr, nub_size_t size, void *buf) DNB_EXPORT;
 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             DNBMemoryRegionInfo     (nub_process_t pid, nub_addr_t addr, DNBRegionInfo *region_info) 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             DNBProcessMemoryRegionInfo  (nub_process_t pid, nub_addr_t addr, DNBRegionInfo *region_info) DNB_EXPORT;
 
 //----------------------------------------------------------------------
 // Process status
diff --git a/lldb/tools/debugserver/source/MacOSX/MachVMMemory.cpp b/lldb/tools/debugserver/source/MacOSX/MachVMMemory.cpp
index 5a9276dd28a..c3c66f84b2e 100644
--- a/lldb/tools/debugserver/source/MacOSX/MachVMMemory.cpp
+++ b/lldb/tools/debugserver/source/MacOSX/MachVMMemory.cpp
@@ -52,7 +52,7 @@ MachVMMemory::MaxBytesLeftInPage(nub_addr_t addr, nub_size_t count)
     return count;
 }
 
-int
+nub_bool_t
 MachVMMemory::GetMemoryRegionInfo(task_t task, nub_addr_t address, DNBRegionInfo *region_info)
 {
     MachVMRegion vmRegion(task);
@@ -62,12 +62,30 @@ MachVMMemory::GetMemoryRegionInfo(task_t task, nub_addr_t address, DNBRegionInfo
         region_info->addr = vmRegion.StartAddress();
         region_info->size = vmRegion.GetByteSize();
         region_info->permissions = vmRegion.GetDNBPermissions();
-        return 1;
     }
-    region_info->addr = 0;
-    region_info->size = 0;
-    region_info->permissions = 0;
-    return 0;
+    else
+    {
+        region_info->addr = address;
+        region_info->size = 0;
+        if (vmRegion.GetError().Success())
+        {
+            // vmRegion.GetRegionForAddress() return false, indicating that "address"
+            // wasn't in a valid region, but the "vmRegion" info was successfully 
+            // read from the task which means the info describes the next valid
+            // region from which we can infer the size of this invalid region
+            mach_vm_address_t start_addr = vmRegion.StartAddress();
+            if (address < start_addr)
+                region_info->size = start_addr - address;
+        }
+        // If we can't get any infor about the size from the next region, just fill
+        // 1 in as the byte size
+        if (region_info->size == 0)
+            region_info->size = 1;
+
+        // Not readable, writeable or executable
+        region_info->permissions = 0;
+    }
+    return true;
 }
 
 nub_size_t
diff --git a/lldb/tools/debugserver/source/MacOSX/MachVMMemory.h b/lldb/tools/debugserver/source/MacOSX/MachVMMemory.h
index e32fa4f4c44..d7162d0d79f 100644
--- a/lldb/tools/debugserver/source/MacOSX/MachVMMemory.h
+++ b/lldb/tools/debugserver/source/MacOSX/MachVMMemory.h
@@ -27,7 +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();
-    int        GetMemoryRegionInfo(task_t task, nub_addr_t address, DNBRegionInfo *region_info);
+    nub_bool_t GetMemoryRegionInfo(task_t task, nub_addr_t address, DNBRegionInfo *region_info);
 
 protected:
     nub_size_t MaxBytesLeftInPage(nub_addr_t addr, nub_size_t count);
diff --git a/lldb/tools/debugserver/source/MacOSX/MachVMRegion.cpp b/lldb/tools/debugserver/source/MacOSX/MachVMRegion.cpp
index e1667f0c196..38757595cfe 100644
--- a/lldb/tools/debugserver/source/MacOSX/MachVMRegion.cpp
+++ b/lldb/tools/debugserver/source/MacOSX/MachVMRegion.cpp
@@ -128,66 +128,59 @@ MachVMRegion::GetRegionForAddress(nub_addr_t addr)
 {
     // Restore any original protections and clear our vars
     Clear();
+    m_err.Clear();
     m_addr = addr;
     m_start = addr;
     m_depth = 1024;
     mach_msg_type_number_t info_size = kRegionInfoSize;
     assert(sizeof(info_size) == 4);
     m_err = ::mach_vm_region_recurse (m_task, &m_start, &m_size, &m_depth, (vm_region_recurse_info_t)&m_data, &info_size);
-    const bool log_protections = DNBLogCheckLogBit(LOG_MEMORY_PROTECTIONS);
-    if (m_err.Success())
-    {
-        if ((addr < m_start) || (addr >= (m_start + m_size)))
-        {
-            m_err.SetErrorString("no region for address");
-            m_err.SetError(-1, DNBError::Generic);
-            if (log_protections)
-                m_err.LogThreaded("::mach_vm_region_recurse ( task = 0x%4.4x, address => 0x%8.8llx, size => %llu, nesting_depth => %d, info => %p, infoCnt => %d) addr = 0x%8.8llx not in range [0x%8.8llx - 0x%8.8llx)", 
-                                  m_task, (uint64_t)m_start, (uint64_t)m_size, m_depth, &m_data, info_size, (uint64_t)addr, (uint64_t)m_start, (uint64_t)m_start + m_size);
-            return false;
-        }
-    }
     
-    if (log_protections || m_err.Fail())
+    const bool failed = m_err.Fail();
+    const bool log_protections = DNBLogCheckLogBit(LOG_MEMORY_PROTECTIONS);
+
+    if (log_protections || failed)
         m_err.LogThreaded("::mach_vm_region_recurse ( task = 0x%4.4x, address => 0x%8.8llx, size => %llu, nesting_depth => %d, info => %p, infoCnt => %d) addr = 0x%8.8llx ", m_task, (uint64_t)m_start, (uint64_t)m_size, m_depth, &m_data, info_size, (uint64_t)addr);
-    if (m_err.Fail())
-    {
+
+    if (failed)
         return false;
-    }
-    else
+    if (log_protections)
     {
-        if (log_protections)
-        {
-            DNBLogThreaded("info = { prot = %u, "
-                             "max_prot = %u, "
-                             "inheritance = 0x%8.8x, "
-                             "offset = 0x%8.8llx, "
-                             "user_tag = 0x%8.8x, "
-                             "ref_count = %u, "
-                             "shadow_depth = %u, "
-                             "ext_pager = %u, "
-                             "share_mode = %u, "
-                             "is_submap = %d, "
-                             "behavior = %d, "
-                             "object_id = 0x%8.8x, "
-                             "user_wired_count = 0x%4.4x }",
-                             m_data.protection,
-                             m_data.max_protection,
-                             m_data.inheritance,
-                             (uint64_t)m_data.offset,
-                             m_data.user_tag,
-                             m_data.ref_count,
-                             m_data.shadow_depth,
-                             m_data.external_pager,
-                             m_data.share_mode,
-                             m_data.is_submap,
-                             m_data.behavior,
-                             m_data.object_id,
-                             m_data.user_wired_count);
-        }
+        DNBLogThreaded("info = { prot = %u, "
+                         "max_prot = %u, "
+                         "inheritance = 0x%8.8x, "
+                         "offset = 0x%8.8llx, "
+                         "user_tag = 0x%8.8x, "
+                         "ref_count = %u, "
+                         "shadow_depth = %u, "
+                         "ext_pager = %u, "
+                         "share_mode = %u, "
+                         "is_submap = %d, "
+                         "behavior = %d, "
+                         "object_id = 0x%8.8x, "
+                         "user_wired_count = 0x%4.4x }",
+                         m_data.protection,
+                         m_data.max_protection,
+                         m_data.inheritance,
+                         (uint64_t)m_data.offset,
+                         m_data.user_tag,
+                         m_data.ref_count,
+                         m_data.shadow_depth,
+                         m_data.external_pager,
+                         m_data.share_mode,
+                         m_data.is_submap,
+                         m_data.behavior,
+                         m_data.object_id,
+                         m_data.user_wired_count);
     }
-
     m_curr_protection = m_data.protection;
+    
+    // We make a request for an address and got no error back, but this
+    // doesn't mean that "addr" is in the range. The data in this object will 
+    // be valid though, so you could see where the next region begins. So we
+    // return false, yet leave "m_err" with a successfull return code.
+    if ((addr < m_start) || (addr >= (m_start + m_size)))
+        return false;
 
     return true;
 }
diff --git a/lldb/tools/debugserver/source/MacOSX/MachVMRegion.h b/lldb/tools/debugserver/source/MacOSX/MachVMRegion.h
index e856f0b2414..bcac60b8318 100644
--- a/lldb/tools/debugserver/source/MacOSX/MachVMRegion.h
+++ b/lldb/tools/debugserver/source/MacOSX/MachVMRegion.h
@@ -47,6 +47,11 @@ public:
     uint32_t
     GetDNBPermissions () const;
 
+    const DNBError &
+    GetError ()
+    {
+        return m_err;
+    }
 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 c640023b21e..deb9db6ad57 100644
--- a/lldb/tools/debugserver/source/RNBRemote.cpp
+++ b/lldb/tools/debugserver/source/RNBRemote.cpp
@@ -3283,52 +3283,28 @@ RNBRemote::HandlePacket_MemoryRegionInfo (const char *p)
     }
 
     DNBRegionInfo region_info = { 0, 0, 0 };
-    int ret = DNBMemoryRegionInfo (m_ctx.ProcessID(), address, &region_info);
+    DNBProcessMemoryRegionInfo (m_ctx.ProcessID(), address, &region_info);
     std::ostringstream ostrm;
 
-    if (ret == 1 && region_info.size > 0)
-    {
         // start:3a50000,size:100000,permissions:rwx
-        ostrm << "start:" << std::hex << region_info.addr << ';'
-              << "size:"  << std::hex << region_info.size << ';';
+    ostrm << "start:" << std::hex << region_info.addr << ';';
+
+    if (region_info.size > 0)
+        ostrm << "size:"  << std::hex << region_info.size << ';';
         
-        if (region_info.permissions)
-        {
-            ostrm << "permissions:";
-            
-            if (region_info.permissions & eMemoryPermissionsReadable)
-                ostrm << 'r';
-            if (region_info.permissions & eMemoryPermissionsWritable)
-                ostrm << 'w';
-            if (region_info.permissions & eMemoryPermissionsExecutable)
-                ostrm << 'x';
-            ostrm << ';';
-        }
-        return SendPacket (ostrm.str());
-    }
-    else
+    if (region_info.permissions)
     {
-        ostrm << std::hex << "error:";
-        const char *error_message = NULL;
-        if (ret == -1)
-        {
-            error_message = "region lookup cannot be performed";
-        }
-        else
-        {
-            error_message = "address in unmapped region";
-        }
-        // hex encode the error message so we can send any characters we want in
-        // the future since this is text
-        const int error_message_len = strlen (error_message);
-        const uint8_t *u_error_message = (const uint8_t *)error_message;
-        for (int i = 0; i < error_message_len; i++)
-            ostrm << RAWHEX8(u_error_message[i]);
+        ostrm << "permissions:";
+        
+        if (region_info.permissions & eMemoryPermissionsReadable)
+            ostrm << 'r';
+        if (region_info.permissions & eMemoryPermissionsWritable)
+            ostrm << 'w';
+        if (region_info.permissions & eMemoryPermissionsExecutable)
+            ostrm << 'x';
         ostrm << ';';
-        return SendPacket (ostrm.str());
     }
-
-    return SendPacket ("E68");
+    return SendPacket (ostrm.str());
 }