[RFA] initialize err variable in load_section_callback()

[Paul Schlie]

If preferred, here's an alternate fix:

In File target.c,

  int
  target_write_memory_partial (CORE_ADDR memaddr, char *buf, int len, int
*err)
  {
    if (target_xfer_partial_p ())
+   {
+     *err = 0;
      return target_xfer_partial (target_stack, TARGET_OBJECT_MEMORY, NULL,
                  NULL, buf, memaddr, len);
+  }
    else
      return target_xfer_memory_partial (memaddr, buf, len, 1, err);
  }

target_xfer_partial nor it's predecessor sets *err, therefore uninitialized.

(bug introduced in version 1.83, by checkin on 9/30/04 by Andrew Cagney)


> From: Paul Schlie <schlie@comcast.net>
> Date: Tue, 04 Jan 2005 02:31:39 -0500
> To: <gdb-patches@sources.redhat.com>
> Cc: "Theodore A. Roth" <troth@openavr.org>, Andrew Cagney <cagney@gnu.org>
> Subject: Re: [RFA] initialize err variable in load_section_callback()
> 
> Might Ted please be given authorization to check his October patch into
> both the 6.3 and head branches, as it fixes an uninitialized variable problem
> which has already been subsequently independently found with identical fixes
> proposed at least a few times since:
> 
>  http://sources.redhat.com/ml/gdb-patches/2004-10/msg00324.html
> 
> (Although there appeared to be some discussion with Andrew on the subject,
>  this fix should be considered the least fragile way to guarantee that
>  the err variable declared within this function's scope is initialized,
>  as it's likely too fragile to assume that all functions which may signal
>  errors, explicitly also signal success [other than via the absents of an
>  error, which typically necessitates the utilized shared signaling variable
>  be initialized as being error-free]. Where then if there is a desire to
>  check/refined all error signaling functions within GDB such that they both
>  explicitly signal success and failure, and guarantee that at least one
>  such function is always called to initialize otherwise un-initialized error
>  variables prior to being tested, this may be done independently of this
>  proposed simple less fragile quick fix.)
>