lldb fix ARM64 register access

[pawelo]

Summary

Apparently, PEEKUSER/POKEUSER is something x86 specific, so I had to rework it for AArch64. This fixes assertion that occurs whenever lldb started on AArch64 device tried to read PC register (or any other register)

[pawelo]

Seems like in my comment to this patch I went too far with the last
statement on llgs - I was refering to the code I'm working on and for a
moment I've forgotten that it's something not complete and not published
yet.

[tfiala]

Hey Paul,

The change looks fine.

Minor formatting nit. Could you adjust your bracing style to match the rest of the code, though? You can either filter it through the clang formatter (there was a thread on how to do that within the last 2 - 3 weeks on lldb-dev or lldb-commits) or adjust the bits I list below. The only bits I'm really noticing are related to else and curly brace starting position.

#1.

else {

would be:
else
{

#2:

} else
{

would be
}
else
{
}

Thanks!

[tfiala]

Hey Paul,

The change looks fine.

Minor formatting nit. Could you adjust your bracing style to match the rest of the code, though? You can either filter it through the clang formatter (there was a thread on how to do that within the last 2 - 3 weeks on lldb-dev or lldb-commits) or adjust the bits I list below. The only bits I'm really noticing are related to else and curly brace starting position.

#1.

else {

would be:
else
{

#2:

} else
{

would be
}
else
{
}

Thanks!

[pawelo]

fixed 'else' formatting

[tfiala]

Thanks, Paul. Having a look at this now.

[tfiala]

svn commit
Sending source/Plugins/Process/Linux/ProcessMonitor.cpp
Transmitting file data .
Committed revision 217691.

source/Plugins/Process/Linux/ProcessMonitor.cpp

 // C Includes
 #include <errno.h>
 #include <poll.h>
 #include <string.h>
 #include <stdint.h>
 #include <unistd.h>
 #include <elf.h>
 #include <sys/personality.h>
+#include <sys/procfs.h>
 #include <sys/ptrace.h>
 #include <sys/uio.h>
 #include <sys/socket.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
 #include <sys/user.h>
 #include <sys/wait.h>
 
private:
     const char *m_reg_name;
     RegisterValue &m_value;
     bool &m_result;
 };
 
 void
 ReadRegOperation::Execute(ProcessMonitor *monitor)
 {
+#if defined (__arm64__) || defined (__aarch64__)
+    if (m_offset > sizeof(struct user_pt_regs))
+    {
+        uintptr_t offset = m_offset - sizeof(struct user_pt_regs);
+        if (offset > sizeof(struct user_fpsimd_state))
+        {
+            m_result = false;
+        }
+        else
+        {
+            elf_fpregset_t regs;
+            int regset = NT_FPREGSET;
+            struct iovec ioVec;
+
+            ioVec.iov_base = &regs;
+            ioVec.iov_len = sizeof regs;
+            if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
+                m_result = false;
+            else
+            {
+                m_result = true;
+                m_value.SetBytes((void *)(((unsigned char *)(&regs)) + offset), 16, monitor->GetProcess().GetByteOrder());
+            }
+        }
+    }
+    else
+    {
+        elf_gregset_t regs;
+        int regset = NT_PRSTATUS;
+        struct iovec ioVec;
+
+        ioVec.iov_base = &regs;
+        ioVec.iov_len = sizeof regs;
+        if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
+            m_result = false;
+        else
+        {
+            m_result = true;
+            m_value.SetBytes((void *)(((unsigned char *)(regs)) + m_offset), 8, monitor->GetProcess().GetByteOrder());
+        }
+    }
+#else
     Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));
 
     // Set errno to zero so that we can detect a failed peek.
     errno = 0;
     lldb::addr_t data = PTRACE(PTRACE_PEEKUSER, m_tid, (void*)m_offset, NULL, 0);
     if (errno)
         m_result = false;
     else
     {
         m_value = data;
         m_result = true;
     }
     if (log)
         log->Printf ("ProcessMonitor::%s() reg %s: 0x%" PRIx64, __FUNCTION__,
                      m_reg_name, data);
+#endif
 }
 
 //------------------------------------------------------------------------------
 /// @class WriteRegOperation
 /// @brief Implements ProcessMonitor::WriteRegisterValue.
 class WriteRegOperation : public Operation
 {
 public:
private:
     const char *m_reg_name;
     const RegisterValue &m_value;
     bool &m_result;
 };
 
 void
 WriteRegOperation::Execute(ProcessMonitor *monitor)
 {
+#if defined (__arm64__) || defined (__aarch64__)
+    if (m_offset > sizeof(struct user_pt_regs))
+    {
+        uintptr_t offset = m_offset - sizeof(struct user_pt_regs);
+        if (offset > sizeof(struct user_fpsimd_state))
+        {
+            m_result = false;
+        }
+        else
+        {
+            elf_fpregset_t regs;
+            int regset = NT_FPREGSET;
+            struct iovec ioVec;
+
+            ioVec.iov_base = &regs;
+            ioVec.iov_len = sizeof regs;
+            if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
+                m_result = false;
+            else
+            {
+                ::memcpy((void *)(((unsigned char *)(&regs)) + offset), m_value.GetBytes(), 16);
+                if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
+                    m_result = false;
+                else
+                    m_result = true;
+            }
+        }
+    }
+    else
+    {
+        elf_gregset_t regs;
+        int regset = NT_PRSTATUS;
+        struct iovec ioVec;
+
+        ioVec.iov_base = &regs;
+        ioVec.iov_len = sizeof regs;
+        if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
+            m_result = false;
+        else
+        {
+            ::memcpy((void *)(((unsigned char *)(&regs)) + m_offset), m_value.GetBytes(), 8);
+            if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
+                m_result = false;
+            else
+                m_result = true;
+        }
+    }
+#else
     void* buf;
     Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));
 
     buf = (void*) m_value.GetAsUInt64();
 
     if (log)
         log->Printf ("ProcessMonitor::%s() reg %s: %p", __FUNCTION__, m_reg_name, buf);
     if (PTRACE(PTRACE_POKEUSER, m_tid, (void*)m_offset, buf, 0))
         m_result = false;
     else
         m_result = true;
+#endif
 }
 
 //------------------------------------------------------------------------------
 /// @class ReadGPROperation
 /// @brief Implements ProcessMonitor::ReadGPR.
 class ReadGPROperation : public Operation
 {
 public: