Re: [PATCH] symtab.c -- Fix off by one allocation bug

[Joel Brobecker <brobecker@adacore.com>]

> This fixes a problem found by valgrind.  Applying this patch caused no
> regressions on GNU/Linux x86-64 and satisfied valgrind.
> 
> 	* gdb/symtab.c (symbol_set_names): Fix off by one error in
> 	allocation.

Thanks for the patch.

Can you give a little more detail as to why we need that extra byte,
and provide that information in the revision log. This kind of
information is always very precious when doing archelogy.

Thanks!

> ---
>  gdb/ChangeLog | 4 ++++
>  gdb/symtab.c  | 2 +-
>  2 files changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/gdb/ChangeLog b/gdb/ChangeLog
> index 9c09269..aaeeb6e 100644
> --- a/gdb/ChangeLog
> +++ b/gdb/ChangeLog
> @@ -1,3 +1,7 @@
> +2016-06-09  David Taylor  <dtaylor@emc.com>
> +
> +	* symtab.c (symbol_set_names): Fix off by one error in allocation.
> +
>  2016-06-07  Simon Marchi  <simon.marchi@ericsson.com>
>  
>  	* mi/mi-interp.c (mi_record_changed): Add missing braces.
> diff --git a/gdb/symtab.c b/gdb/symtab.c
> index f7a207a..12e1cf5 100644
> --- a/gdb/symtab.c
> +++ b/gdb/symtab.c
> @@ -1010,7 +1010,7 @@ symbol_set_names (struct general_symbol_info *gsymbol,
>  	    = ((struct demangled_name_entry *)
>  	       obstack_alloc (&per_bfd->storage_obstack,
>  			      offsetof (struct demangled_name_entry, demangled)
> -			      + lookup_len + demangled_len + 2));
> +			      + lookup_len + demangled_len + 3));
>  	  mangled_ptr = &((*slot)->demangled[demangled_len + 1]);
>  	  strcpy (mangled_ptr, lookup_name);
>  	  (*slot)->mangled = mangled_ptr;
> -- 
> 1.9.1

-- 
Joel