1 files changed, 19 insertions, 22 deletions

diff --git a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
index cb95da9..1e2e3a8 100644
--- a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
+++ b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
@@ -1641,6 +1641,10 @@ NativeProcessLinux::GetSoftwareBreakpointTrapOpcode(size_t size_hint) {
 
 Status NativeProcessLinux::ReadMemory(lldb::addr_t addr, void *buf, size_t size,
                                       size_t &bytes_read) {
+  Log *log = GetLog(POSIXLog::Memory);
+  LLDB_LOG(log, "addr = {0}, buf = {1}, size = {2}", addr, buf, size);
+
+  bytes_read = 0;
   if (ProcessVmReadvSupported()) {
     // The process_vm_readv path is about 50 times faster than ptrace api. We
     // want to use this syscall if it is supported.
@@ -1651,32 +1655,29 @@ Status NativeProcessLinux::ReadMemory(lldb::addr_t addr, void *buf, size_t size,
     remote_iov.iov_base = reinterpret_cast<void *>(addr);
     remote_iov.iov_len = size;
 
-    bytes_read = process_vm_readv(GetCurrentThreadID(), &local_iov, 1,
-                                  &remote_iov, 1, 0);
-    const bool success = bytes_read == size;
+    ssize_t read_result = process_vm_readv(GetCurrentThreadID(), &local_iov, 1,
+                                           &remote_iov, 1, 0);
+    int error = 0;
+    if (read_result < 0)
+      error = errno;
+    else
+      bytes_read = read_result;
 
-    Log *log = GetLog(POSIXLog::Process);
     LLDB_LOG(log,
-             "using process_vm_readv to read {0} bytes from inferior "
-             "address {1:x}: {2}",
-             size, addr, success ? "Success" : llvm::sys::StrError(errno));
-
-    if (success)
-      return Status();
-    // else the call failed for some reason, let's retry the read using ptrace
-    // api.
+             "process_vm_readv({0}, [iovec({1}, {2})], [iovec({3:x}, {2})], 1, "
+             "0) => {4} ({5})",
+             GetCurrentThreadID(), buf, size, addr, read_result,
+             error > 0 ? llvm::sys::StrError(errno) : "sucesss");
   }
 
   unsigned char *dst = static_cast<unsigned char *>(buf);
   size_t remainder;
   long data;
 
-  Log *log = GetLog(POSIXLog::Memory);
-  LLDB_LOG(log, "addr = {0}, buf = {1}, size = {2}", addr, buf, size);
-
-  for (bytes_read = 0; bytes_read < size; bytes_read += remainder) {
+  for (; bytes_read < size; bytes_read += remainder) {
     Status error = NativeProcessLinux::PtraceWrapper(
-        PTRACE_PEEKDATA, GetCurrentThreadID(), (void *)addr, nullptr, 0, &data);
+        PTRACE_PEEKDATA, GetCurrentThreadID(),
+        reinterpret_cast<void *>(addr + bytes_read), nullptr, 0, &data);
     if (error.Fail())
       return error;
 
@@ -1684,11 +1685,7 @@ Status NativeProcessLinux::ReadMemory(lldb::addr_t addr, void *buf, size_t size,
     remainder = remainder > k_ptrace_word_size ? k_ptrace_word_size : remainder;
 
     // Copy the data into our buffer
-    memcpy(dst, &data, remainder);
-
-    LLDB_LOG(log, "[{0:x}]:{1:x}", addr, data);
-    addr += k_ptrace_word_size;
-    dst += k_ptrace_word_size;
+    memcpy(dst + bytes_read, &data, remainder);
   }
   return Status();
 }