Re: [patch] nto-procfs.c: Add to_xfer_partial

[Aleksandar Ristovski <aristovski@qnx.com>]

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ping?

Attached patch is updated to reflect changes that went in 
meanwhile (passing byte order to extract_unsigned_integer).

ChangeLog:

* nto-procfs.c (procfs_xfer_partial): New function.
(init_procfs_ops): Register to_xfer_partial.
* nto-tdep.c (nto_read_auxv_from_initial_stack): Define.
* nto-tdep.h (nto_read_auxv_from_initial_stack): Declare.



Aleksandar Ristovski wrote:
> is this ok to commit?
> 
> Pierre Muller wrote:
>> Hi Aleksandar,
>>  
>>> -----Message d'origine-----
>>> De : gdb-patches-owner@sourceware.org [mailto:gdb-patches-
>>> owner@sourceware.org] De la part de Aleksandar Ristovski
>>> Envoyé : Friday, June 12, 2009 4:25 AM
>>> À : gdb-patches@sources.redhat.com
>>> Objet : Re: [patch] nto-procfs.c: Add to_xfer_partial
>>>
>>> Pierre Muller wrote:
>>>> Hi Aleksandar,
>>> Hello Pierre,
>>>
>>> Thank you for your comments. I think I have addressed all issues you
>>> listed. Please see attached patch.
>>>
>>> Thanks,
>>   I agree that you addressed my concerns. As I said earlier, I am 
>> unable to evaluate the patch
>> in its functionality.
>>
>> Thanks for your fast reply,
>>
>>
>> Pierre Muller
>> Pascal language support maintainer for GDB
>>
>>
>>
>>
> 
> 


Thanks,

-- 
Aleksandar Ristovski
QNX Software Systems

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Index: gdb/nto-procfs.c
===================================================================
RCS file: /cvs/src/src/gdb/nto-procfs.c,v
retrieving revision 1.47
diff -u -p -r1.47 nto-procfs.c
--- gdb/nto-procfs.c	2 Jul 2009 17:12:25 -0000	1.47
+++ gdb/nto-procfs.c	7 Jul 2009 16:16:23 -0000
@@ -774,6 +774,39 @@ procfs_xfer_memory (CORE_ADDR memaddr, g
   return (nbytes);
 }
 
+static LONGEST
+procfs_xfer_partial (struct target_ops *ops, enum target_object object,
+		     const char *annex, gdb_byte *readbuf,
+		     const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
+{
+  if (object == TARGET_OBJECT_AUXV
+      && readbuf)
+    {
+      int err;
+      CORE_ADDR initial_stack;
+      debug_process_t procinfo;
+
+      if (offset > 0)
+	return 0;
+
+      err = devctl (ctl_fd, DCMD_PROC_INFO, &procinfo, sizeof procinfo, 0);
+      if (err != EOK)
+	return -1;
+
+      /* Similar as in the case of a core file, we read auxv from
+         initial_stack.  */
+      initial_stack = procinfo.initial_stack;
+
+      /* procfs is always 'self-hosted', no byte-order manipulation. */
+      return nto_read_auxv_from_initial_stack (initial_stack, readbuf, len);
+    }
+
+  if (ops->beneath && ops->beneath->to_xfer_partial)
+    return ops->beneath->to_xfer_partial (ops, object, annex, readbuf,
+					  writebuf, offset, len);
+  return -1;
+}
+
 /* Take a program previously attached to and detaches it.
    The program resumes execution and will no longer stop
    on signals, etc.  We'd better not have left any breakpoints
@@ -1307,6 +1340,7 @@ init_procfs_ops (void)
   procfs_ops.to_store_registers = procfs_store_registers;
   procfs_ops.to_prepare_to_store = procfs_prepare_to_store;
   procfs_ops.deprecated_xfer_memory = procfs_xfer_memory;
+  procfs_ops.to_xfer_partial = procfs_xfer_partial;
   procfs_ops.to_files_info = procfs_files_info;
   procfs_ops.to_insert_breakpoint = procfs_insert_breakpoint;
   procfs_ops.to_remove_breakpoint = procfs_remove_breakpoint;
Index: gdb/nto-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/nto-tdep.c,v
retrieving revision 1.34
diff -u -p -r1.34 nto-tdep.c
--- gdb/nto-tdep.c	12 Jun 2009 02:32:10 -0000	1.34
+++ gdb/nto-tdep.c	7 Jul 2009 16:16:23 -0000
@@ -364,6 +364,70 @@ nto_initialize_signals (void)
 #endif
 }
 
+LONGEST
+nto_read_auxv_from_initial_stack (CORE_ADDR initial_stack, gdb_byte *readbuf,
+				  LONGEST len)
+{
+  gdb_byte targ32[4]; /* For 32 bit target values.  */
+  CORE_ADDR data_ofs = 0;
+  ULONGEST anint;
+  LONGEST len_read = 0;
+  gdb_byte *buff;
+  /* For 32-bit architecture, size of auxv_t is 8 bytes.  */
+  const unsigned int sizeof_auxv_t = 8;
+  enum bfd_endian byte_order;
+
+  /* Skip over argc, argv and envp... (see comment in ldd.c)  */
+  if (target_read_memory (initial_stack + data_ofs, targ32, sizeof (targ32))
+      != 0)
+    return 0;
+
+  byte_order = gdbarch_byte_order (target_gdbarch);
+
+  anint = extract_unsigned_integer (targ32, sizeof (targ32), byte_order);
+
+  /* Size of pointer is assumed to be 4 bytes (32 bit arch.) */
+  data_ofs += (anint + 2) * sizeof (targ32); /* + 2 comes from argc itself and
+						NULL terminating pointer in
+						argv.  */
+
+  /* Now loop over env table:  */
+  while (target_read_memory (initial_stack + data_ofs, targ32, sizeof (targ32))
+	 == 0)
+    {
+      anint = extract_unsigned_integer (targ32, sizeof (targ32), byte_order);
+      data_ofs += sizeof (targ32);
+      if (anint == 0)
+	break;
+    }
+  initial_stack += data_ofs;
+
+  memset (readbuf, 0, len);
+  buff = readbuf;
+  while (len_read <= len-sizeof_auxv_t)
+    {
+      /* Search backwards until we have read AT_PHDR (num. 3),
+	 AT_PHENT (num 4), AT_PHNUM (num 5)  */
+      if (target_read_memory (initial_stack, buff, sizeof_auxv_t)
+	  == 0)
+	{
+	  ULONGEST a_type = extract_unsigned_integer (buff, sizeof (targ32),
+						      byte_order);
+	  if (a_type != AT_NULL)
+	    {
+	      buff += sizeof_auxv_t;
+	      len_read += sizeof_auxv_t;
+	    }
+	  if (a_type == AT_PHNUM) /* That's all we need.  */
+	    break;
+	  initial_stack += sizeof_auxv_t;
+	}
+      else
+	break;
+    }
+  return len_read;
+}
+
 /* Provide a prototype to silence -Wmissing-prototypes.  */
 extern initialize_file_ftype _initialize_nto_tdep;
 
Index: gdb/nto-tdep.h
===================================================================
RCS file: /cvs/src/src/gdb/nto-tdep.h,v
retrieving revision 1.16
diff -u -p -r1.16 nto-tdep.h
--- gdb/nto-tdep.h	12 Jun 2009 02:32:10 -0000	1.16
+++ gdb/nto-tdep.h	7 Jul 2009 16:16:23 -0000
@@ -162,4 +162,8 @@ void nto_dummy_supply_regset (struct reg
 
 int nto_in_dynsym_resolve_code (CORE_ADDR pc);
 
+LONGEST nto_read_auxv_from_initial_stack (CORE_ADDR inital_stack,
+					  gdb_byte *readbuf,
+					  LONGEST len);
+
 #endif