gdb/gdbserver/

[external/binutils.git] / gdb / gdbserver / remote-utils.c

diff --git a/gdb/gdbserver/remote-utils.c b/gdb/gdbserver/remote-utils.c
index 164ce6a..3dfd1c9 100644 (file)
--- a/gdb/gdbserver/remote-utils.c
+++ b/gdb/gdbserver/remote-utils.c
@@ -1127,7 +1127,7 @@ write_enn (char *buf)
 }
 
 void
-convert_int_to_ascii (unsigned char *from, char *to, int n)
+convert_int_to_ascii (const unsigned char *from, char *to, int n)
 {
   int nib;
   int ch;
@@ -1144,7 +1144,7 @@ convert_int_to_ascii (unsigned char *from, char *to, int n)
 
 
 void
-convert_ascii_to_int (char *from, unsigned char *to, int n)
+convert_ascii_to_int (const char *from, unsigned char *to, int n)
 {
   int nib1, nib2;
   while (n--)
@@ -1354,7 +1354,7 @@ decode_m_packet (char *from, CORE_ADDR *mem_addr_ptr, unsigned int *len_ptr)
 
 void
 decode_M_packet (char *from, CORE_ADDR *mem_addr_ptr, unsigned int *len_ptr,
-                unsigned char *to)
+                unsigned char **to_p)
 {
   int i = 0;
   char ch;
@@ -1372,12 +1372,15 @@ decode_M_packet (char *from, CORE_ADDR *mem_addr_ptr, unsigned int *len_ptr,
       *len_ptr |= fromhex (ch) & 0x0f;
     }
 
-  convert_ascii_to_int (&from[i++], to, *len_ptr);
+  if (*to_p == NULL)
+    *to_p = xmalloc (*len_ptr);
+
+  convert_ascii_to_int (&from[i++], *to_p, *len_ptr);
 }
 
 int
 decode_X_packet (char *from, int packet_len, CORE_ADDR *mem_addr_ptr,
-                unsigned int *len_ptr, unsigned char *to)
+                unsigned int *len_ptr, unsigned char **to_p)
 {
   int i = 0;
   char ch;
@@ -1395,8 +1398,11 @@ decode_X_packet (char *from, int packet_len, CORE_ADDR *mem_addr_ptr,
       *len_ptr |= fromhex (ch) & 0x0f;
     }
 
+  if (*to_p == NULL)
+    *to_p = xmalloc (*len_ptr);
+
   if (remote_unescape_input ((const gdb_byte *) &from[i], packet_len - i,
-                            to, *len_ptr) != *len_ptr)
+                            *to_p, *len_ptr) != *len_ptr)
     return -1;
 
   return 0;
@@ -1565,6 +1571,101 @@ look_up_one_symbol (const char *name, CORE_ADDR *addrp, int may_ask_gdb)
   return 1;
 }
 
+/* Relocate an instruction to execute at a different address.  OLDLOC
+   is the address in the inferior memory where the instruction to
+   relocate is currently at.  On input, TO points to the destination
+   where we want the instruction to be copied (and possibly adjusted)
+   to.  On output, it points to one past the end of the resulting
+   instruction(s).  The effect of executing the instruction at TO
+   shall be the same as if executing it at FROM.  For example, call
+   instructions that implicitly push the return address on the stack
+   should be adjusted to return to the instruction after OLDLOC;
+   relative branches, and other PC-relative instructions need the
+   offset adjusted; etc.  Returns 0 on success, -1 on failure.  */
+
+int
+relocate_instruction (CORE_ADDR *to, CORE_ADDR oldloc)
+{
+  char own_buf[266];
+  int len;
+  ULONGEST written = 0;
+
+  /* Send the request.  */
+  strcpy (own_buf, "qRelocInsn:");
+  sprintf (own_buf, "qRelocInsn:%s;%s", paddress (oldloc),
+          paddress (*to));
+  if (putpkt (own_buf) < 0)
+    return -1;
+
+  /* FIXME:  Eventually add buffer overflow checking (to getpkt?)  */
+  len = getpkt (own_buf);
+  if (len < 0)
+    return -1;
+
+  /* We ought to handle pretty much any packet at this point while we
+     wait for the qRelocInsn "response".  That requires re-entering
+     the main loop.  For now, this is an adequate approximation; allow
+     GDB to access memory.  */
+  while (own_buf[0] == 'm' || own_buf[0] == 'M' || own_buf[0] == 'X')
+    {
+      CORE_ADDR mem_addr;
+      unsigned char *mem_buf = NULL;
+      unsigned int mem_len;
+
+      if (own_buf[0] == 'm')
+       {
+         decode_m_packet (&own_buf[1], &mem_addr, &mem_len);
+         mem_buf = xmalloc (mem_len);
+         if (read_inferior_memory (mem_addr, mem_buf, mem_len) == 0)
+           convert_int_to_ascii (mem_buf, own_buf, mem_len);
+         else
+           write_enn (own_buf);
+       }
+      else if (own_buf[0] == 'X')
+       {
+         if (decode_X_packet (&own_buf[1], len - 1, &mem_addr,
+                              &mem_len, &mem_buf) < 0
+             || write_inferior_memory (mem_addr, mem_buf, mem_len) != 0)
+           write_enn (own_buf);
+         else
+           write_ok (own_buf);
+       }
+      else
+       {
+         decode_M_packet (&own_buf[1], &mem_addr, &mem_len, &mem_buf);
+         if (write_inferior_memory (mem_addr, mem_buf, mem_len) == 0)
+           write_ok (own_buf);
+         else
+           write_enn (own_buf);
+       }
+      free (mem_buf);
+      if (putpkt (own_buf) < 0)
+       return -1;
+      len = getpkt (own_buf);
+      if (len < 0)
+       return -1;
+    }
+
+  if (own_buf[0] == 'E')
+    {
+      warning ("An error occurred while relocating an instruction: %s\n",
+              own_buf);
+      return -1;
+    }
+
+  if (strncmp (own_buf, "qRelocInsn:", strlen ("qRelocInsn:")) != 0)
+    {
+      warning ("Malformed response to qRelocInsn, ignoring: %s\n",
+              own_buf);
+      return -1;
+    }
+
+  unpack_varlen_hex (own_buf + strlen ("qRelocInsn:"), &written);
+
+  *to += written;
+  return 0;
+}
+
 void
 monitor_output (const char *msg)
 {