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* [rfa] add_symbol_file_command, avoid memory leak.
@ 2011-02-27  1:56 Michael Snyder
  2011-02-27 20:35 ` Jan Kratochvil
  0 siblings, 1 reply; 6+ messages in thread
From: Michael Snyder @ 2011-02-27  1:56 UTC (permalink / raw)
  To: gdb-patches

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This looks straightforward, but I'd appreciate review.
I don't really understand why sect_opts never gets freed?


[-- Attachment #2: symfile.txt --]
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2011-02-26  Michael Snyder  <msnyder@vmware.com>

	* symfile.c (add_symbol_file_command): Avoid memory leak.

Index: symfile.c
===================================================================
RCS file: /cvs/src/src/gdb/symfile.c,v
retrieving revision 1.307
diff -u -p -u -p -r1.307 symfile.c
--- symfile.c	26 Feb 2011 02:07:09 -0000	1.307
+++ symfile.c	27 Feb 2011 01:35:32 -0000
@@ -2169,15 +2169,15 @@ add_symbol_file_command (char *args, int
   size_t num_sect_opts = 0;
   struct cleanup *my_cleanups = make_cleanup (null_cleanup, NULL);
 
+  if (args == NULL)
+    error (_("add-symbol-file takes a file name and an address"));
+
   num_sect_opts = 16;
   sect_opts = (struct sect_opt *) xmalloc (num_sect_opts
 					   * sizeof (struct sect_opt));
 
   dont_repeat ();
 
-  if (args == NULL)
-    error (_("add-symbol-file takes a file name and an address"));
-
   argv = gdb_buildargv (args);
   make_cleanup_freeargv (argv);
 

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [rfa] add_symbol_file_command, avoid memory leak.
  2011-02-27  1:56 [rfa] add_symbol_file_command, avoid memory leak Michael Snyder
@ 2011-02-27 20:35 ` Jan Kratochvil
  2011-02-27 20:42   ` Michael Snyder
  0 siblings, 1 reply; 6+ messages in thread
From: Jan Kratochvil @ 2011-02-27 20:35 UTC (permalink / raw)
  To: Michael Snyder; +Cc: gdb-patches

On Sun, 27 Feb 2011 02:38:04 +0100, Michael Snyder wrote:
> This looks straightforward, but I'd appreciate review.
> I don't really understand why sect_opts never gets freed?

It is a bug, sect_opts should be freed.  It is last time used by the lines:
      char *val = sect_opts[i].value;
      char *sec = sect_opts[i].name;

The strings in sect_opts[i].name are last time used there by:
  symbol_file_add (filename, from_tty ? SYMFILE_VERBOSE : 0,
                   section_addrs, flags);

This is also the reason why the NAMEs do not have strdup() and they get safely
freed through make_cleanup_freeargv there.


> --- symfile.c	26 Feb 2011 02:07:09 -0000	1.307
> +++ symfile.c	27 Feb 2011 01:35:32 -0000
> @@ -2169,15 +2169,15 @@ add_symbol_file_command (char *args, int
>    size_t num_sect_opts = 0;
>    struct cleanup *my_cleanups = make_cleanup (null_cleanup, NULL);
>  
> +  if (args == NULL)
> +    error (_("add-symbol-file takes a file name and an address"));
> +
>    num_sect_opts = 16;
>    sect_opts = (struct sect_opt *) xmalloc (num_sect_opts
>  					   * sizeof (struct sect_opt));
>  
>    dont_repeat ();
>  
> -  if (args == NULL)
> -    error (_("add-symbol-file takes a file name and an address"));
> -
>    argv = gdb_buildargv (args);
>    make_cleanup_freeargv (argv);
>  

While a nitpick it is a regression, that dont_repeat should be called even in
the case of that error.


Thanks,
Jan


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [rfa] add_symbol_file_command, avoid memory leak.
  2011-02-27 20:35 ` Jan Kratochvil
@ 2011-02-27 20:42   ` Michael Snyder
  2011-02-27 20:51     ` Jan Kratochvil
  0 siblings, 1 reply; 6+ messages in thread
From: Michael Snyder @ 2011-02-27 20:42 UTC (permalink / raw)
  To: Jan Kratochvil; +Cc: gdb-patches

Jan Kratochvil wrote:
> On Sun, 27 Feb 2011 02:38:04 +0100, Michael Snyder wrote:
>> This looks straightforward, but I'd appreciate review.
>> I don't really understand why sect_opts never gets freed?
> 
> It is a bug, sect_opts should be freed.  It is last time used by the lines:
>       char *val = sect_opts[i].value;
>       char *sec = sect_opts[i].name;
> 
> The strings in sect_opts[i].name are last time used there by:
>   symbol_file_add (filename, from_tty ? SYMFILE_VERBOSE : 0,
>                    section_addrs, flags);
> 
> This is also the reason why the NAMEs do not have strdup() and they get safely
> freed through make_cleanup_freeargv there.
> 
> 
>> --- symfile.c	26 Feb 2011 02:07:09 -0000	1.307
>> +++ symfile.c	27 Feb 2011 01:35:32 -0000
>> @@ -2169,15 +2169,15 @@ add_symbol_file_command (char *args, int
>>    size_t num_sect_opts = 0;
>>    struct cleanup *my_cleanups = make_cleanup (null_cleanup, NULL);
>>  
>> +  if (args == NULL)
>> +    error (_("add-symbol-file takes a file name and an address"));
>> +
>>    num_sect_opts = 16;
>>    sect_opts = (struct sect_opt *) xmalloc (num_sect_opts
>>  					   * sizeof (struct sect_opt));
>>  
>>    dont_repeat ();
>>  
>> -  if (args == NULL)
>> -    error (_("add-symbol-file takes a file name and an address"));
>> -
>>    argv = gdb_buildargv (args);
>>    make_cleanup_freeargv (argv);
>>  
> 
> While a nitpick it is a regression, that dont_repeat should be called even in
> the case of that error.


No, it's a fix.  I moved the error before dont_repeat.


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [rfa] add_symbol_file_command, avoid memory leak.
  2011-02-27 20:42   ` Michael Snyder
@ 2011-02-27 20:51     ` Jan Kratochvil
  2011-02-27 22:00       ` Michael Snyder
  0 siblings, 1 reply; 6+ messages in thread
From: Jan Kratochvil @ 2011-02-27 20:51 UTC (permalink / raw)
  To: Michael Snyder; +Cc: gdb-patches

On Sun, 27 Feb 2011 21:35:46 +0100, Michael Snyder wrote:
> Jan Kratochvil wrote:
> > While a nitpick it is a regression, that dont_repeat should be called even
> > in the case of that error.
> 
> No, it's a fix.  I moved the error before dont_repeat.

Why?  The manual says:
	`add-symbol-file' does not repeat if you press <RET> after using it.
Other part of the manual says:
	and you can repeat certain GDB commands by typing just <RET>.

There is nothing said that whether the command is / is not repated depends on
its entered arguments.

(Not sure if it matters to continue the discussion, I do not mind either way.)


Regards,
Jan


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [rfa] add_symbol_file_command, avoid memory leak.
  2011-02-27 20:51     ` Jan Kratochvil
@ 2011-02-27 22:00       ` Michael Snyder
  2011-02-27 22:12         ` Jan Kratochvil
  0 siblings, 1 reply; 6+ messages in thread
From: Michael Snyder @ 2011-02-27 22:00 UTC (permalink / raw)
  To: Jan Kratochvil; +Cc: gdb-patches

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Jan Kratochvil wrote:
> On Sun, 27 Feb 2011 21:35:46 +0100, Michael Snyder wrote:
>> Jan Kratochvil wrote:
>>> While a nitpick it is a regression, that dont_repeat should be called even
>>> in the case of that error.
>> No, it's a fix.  I moved the error before dont_repeat.
> 
> Why?  The manual says:
> 	`add-symbol-file' does not repeat if you press <RET> after using it.
> Other part of the manual says:
> 	and you can repeat certain GDB commands by typing just <RET>.
> 
> There is nothing said that whether the command is / is not repated depends on
> its entered arguments.
> 
> (Not sure if it matters to continue the discussion, I do not mind either way.)

Ah, sorry, I misunderstood you.  I'm with you now.

How about this?




[-- Attachment #2: symfile2.txt --]
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2011-02-26  Michael Snyder  <msnyder@vmware.com>

	* symfile.c (add_symbol_file_command): Avoid memory leak.

Index: symfile.c
===================================================================
RCS file: /cvs/src/src/gdb/symfile.c,v
retrieving revision 1.307
diff -u -p -u -p -r1.307 symfile.c
--- symfile.c	26 Feb 2011 02:07:09 -0000	1.307
+++ symfile.c	27 Feb 2011 21:56:20 -0000
@@ -2169,15 +2169,15 @@ add_symbol_file_command (char *args, int
   size_t num_sect_opts = 0;
   struct cleanup *my_cleanups = make_cleanup (null_cleanup, NULL);
 
-  num_sect_opts = 16;
-  sect_opts = (struct sect_opt *) xmalloc (num_sect_opts
-					   * sizeof (struct sect_opt));
-
   dont_repeat ();
 
   if (args == NULL)
     error (_("add-symbol-file takes a file name and an address"));
 
+  num_sect_opts = 16;
+  sect_opts = (struct sect_opt *) xmalloc (num_sect_opts
+					   * sizeof (struct sect_opt));
+
   argv = gdb_buildargv (args);
   make_cleanup_freeargv (argv);
 

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [rfa] add_symbol_file_command, avoid memory leak.
  2011-02-27 22:00       ` Michael Snyder
@ 2011-02-27 22:12         ` Jan Kratochvil
  0 siblings, 0 replies; 6+ messages in thread
From: Jan Kratochvil @ 2011-02-27 22:12 UTC (permalink / raw)
  To: Michael Snyder; +Cc: gdb-patches

On Sun, 27 Feb 2011 22:57:09 +0100, Michael Snyder wrote:
> @@ -2169,15 +2169,15 @@ add_symbol_file_command (char *args, int
>    size_t num_sect_opts = 0;
>    struct cleanup *my_cleanups = make_cleanup (null_cleanup, NULL);
>  
> -  num_sect_opts = 16;
> -  sect_opts = (struct sect_opt *) xmalloc (num_sect_opts
> -					   * sizeof (struct sect_opt));
> -
>    dont_repeat ();
>  
>    if (args == NULL)
>      error (_("add-symbol-file takes a file name and an address"));
>  
> +  num_sect_opts = 16;
> +  sect_opts = (struct sect_opt *) xmalloc (num_sect_opts
> +					   * sizeof (struct sect_opt));
> +
>    argv = gdb_buildargv (args);
>    make_cleanup_freeargv (argv);
>  

> How about this?

Yes, the fix is OK now.  There could be also added some
	make_cleanup (xfree, sect_opts);

as discussed before; but it may be a different patch.


Thanks,
Jan


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2011-02-27 22:05 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2011-02-27  1:56 [rfa] add_symbol_file_command, avoid memory leak Michael Snyder
2011-02-27 20:35 ` Jan Kratochvil
2011-02-27 20:42   ` Michael Snyder
2011-02-27 20:51     ` Jan Kratochvil
2011-02-27 22:00       ` Michael Snyder
2011-02-27 22:12         ` Jan Kratochvil

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