2004-10-01 Andrew Cagney <cagney@gnu.org>

	* target.c (xfer_using_stratum): Change return type to LONGEST.
	On each iteration offset, readbuf and writebuf.
	* inf-ptrace.c (inf_ptrace_xfer_partial): Simplify computation of
	partial_length, and read/modify/write predicate, update comments.
	Pass buffer.word to ptrace write.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 62819e798dc79cc24ae95bff402d859c7e07a43d..bfeaea03381e49dbeef26eebd2ec21b769ddedbd 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,11 @@
+2004-10-01  Andrew Cagney  <cagney@gnu.org>
+
+       * target.c (xfer_using_stratum): Change return type to LONGEST.
+       On each iteration offset, readbuf and writebuf.
+       * inf-ptrace.c (inf_ptrace_xfer_partial): Simplify computation of
+       partial_length, and read/modify/write predicate, update comments.
+       Pass buffer.word to ptrace write.
+
 2004-10-01  Paul N. Hilfinger  <Hilfinger@gnat.com>
 
        * symfile.c (init_filename_language_table): Add extensions for

diff --git a/gdb/inf-ptrace.c b/gdb/inf-ptrace.c
index 4a37d394d63966745c889f63554efc2085482565..0aa6fd17c81549c523031cb67cce914489fc389f 100644 (file)
--- a/gdb/inf-ptrace.c
+++ b/gdb/inf-ptrace.c
@@ -514,25 +514,27 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
        ULONGEST rounded_offset;
        LONGEST partial_len;
        
-       /* Round the start address down to the next long word boundary.  */
+       /* Round the start offset down to the next long word
+          boundary.  */
        rounded_offset = offset & -(ULONGEST) sizeof (PTRACE_TYPE_RET);
        
-       /* Truncate the length so that at max a single word will be
-          transfered.  Remember, this function is required to perform
-          only a partial read so no more than one word should be
-          transfered).  */
-       if (rounded_offset + sizeof (PTRACE_TYPE_RET) < offset + len)
-         partial_len = sizeof (PTRACE_TYPE_RET) - (offset - rounded_offset);
-       else
+       /* Since ptrace will transfer a single word starting at that
+          rounded_offset the partial_len needs to be adjusted down to
+          that (remember this function only does a single transfer).
+          Should the required length be even less, adjust it down
+          again.  */
+       partial_len = (rounded_offset + sizeof (PTRACE_TYPE_RET)) - offset;
+       if (partial_len > len)
          partial_len = len;
        
        if (writebuf)
          {
-           /* Fill start and end extra bytes of buffer with existing
-              memory data.  */
+           /* If OFFSET:PARTIAL_LEN is smaller than
+              ROUNDED_OFFSET:WORDSIZE then a read/modify write will
+              be needed.  Read in the entire word.  */
            if (rounded_offset < offset
-               || (partial_len + (offset - rounded_offset)
-                   < sizeof (PTRACE_TYPE_RET)))
+               || (offset + partial_len
+                   < rounded_offset + sizeof (PTRACE_TYPE_RET)))
              /* Need part of initial word -- fetch it.  */
              buffer.word = ptrace (PT_READ_I, PIDGET (inferior_ptid),
                                    (PTRACE_TYPE_ARG3) (long) rounded_offset,
@@ -545,7 +547,7 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
            errno = 0;
            ptrace (PT_WRITE_D, PIDGET (inferior_ptid),
                    (PTRACE_TYPE_ARG3) (long) rounded_offset,
-                   (int) buffer.byte);
+                   buffer.word);
            if (errno)
              {
                /* Using the appropriate one (I or D) is necessary for
@@ -553,7 +555,7 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
                errno = 0;
                ptrace (PT_WRITE_I, PIDGET (inferior_ptid),
                        (PTRACE_TYPE_ARG3) (long) rounded_offset,
-                       (int) buffer.byte);
+                       buffer.word);
                if (errno)
                  return 0;
              }

diff --git a/gdb/target.c b/gdb/target.c
index 81784da4a411e1a6f2c2e9d658a66a26ed030e87..48bf8fb6f5abd12bce2643a76015dd2bee04f777 100644 (file)
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -927,9 +927,9 @@ target_xfer_partial (struct target_ops *ops,
    implementing another singluar mechanism (for instance, a generic
    object:annex onto inferior:object:annex say).  */
 
-static int
+static LONGEST
 xfer_using_stratum (enum target_object object, const char *annex,
-                   CORE_ADDR memaddr, int len, void *readbuf,
+                   ULONGEST offset, LONGEST len, void *readbuf,
                    const void *writebuf)
 {
   LONGEST xfered;
@@ -946,7 +946,7 @@ xfer_using_stratum (enum target_object object, const char *annex,
   while (1)
     {
       xfered = target_xfer_partial (target, object, annex,
-                                   readbuf, writebuf, memaddr, len);
+                                   readbuf, writebuf, offset, len);
       if (xfered > 0)
        {
          /* The partial xfer succeeded, update the counts, check that
@@ -955,6 +955,11 @@ xfer_using_stratum (enum target_object object, const char *annex,
          len -= xfered;
          if (len <= 0)
            return 0;
+         offset += xfered;
+         if (readbuf != NULL)
+           readbuf = (bfd_byte *) readbuf + xfered;
+         if (writebuf != NULL)
+           writebuf = (bfd_byte *) writebuf + xfered;
          target = target_stack;
        }
       else if (xfered < 0)