Re: [gold patch] Fix usage of invalidated version string in Symbol_table::define_special_symbol

[Ian Lance Taylor <iant at google dot com>]

Viktor Kutuzov <vkutuzov@accesssoftek.com> writes:

> This patch fixes a problem with canonicalization of the symbols, but we
> still have a problem with the invalidated version string. You left an
> assignment of *pversion from v at its old place, but in case of true
> condition at line 1679 we will get a pointer to an invalidated string in
> *pversion by leaving the method.
>
> symtab.cc ---
>   ...
>   if (only_if_ref)
>     {
>       // Look up for the externaly specified or default (NULL) versions.
>       oldsym = this->lookup(*pname, *pversion);
>       // Look up for the script specified default version.
>       if (oldsym == NULL && is_default_version)
> 	oldsym = this->lookup(*pname, v.c_str());
>       if (oldsym == NULL || !oldsym->is_undefined())
> 	return NULL;	<<<<<<<< HERE !!!

But if this function returns NULL, the value stored in *pversion is
irrelevant.  Isn't it?

Ian

> On Tue, 2011-09-27 at 17:55 -0700, Ian Lance Taylor wrote:
>> Viktor Kutuzov <vkutuzov@accesssoftek.com> writes:
>> 
>> > I found that the Symbol_table::define_special_symbol method can return a
>> > pointer to an invalidated version string from the local std::string
>> > object (v) in case of condition only_if_ref == true. This patch should
>> > fix this problem.
>> >
>> > -Viktor.
>> >
>> > 	* symtab.cc (Symbol_table::define_special_symbol): Fix usage of
>> > 	the invalidated version string.
>> 
>> Thanks for the bug report and patch.  I don't think your approach is
>> entirely correct.  If the version is the default, we still want to look
>> up the symbol with a NULL version.  Also, if is_default_version is true
>> we know that *pversion != NULL.  I think this patch will fix the
>> problem.  Committed to mainline and 2.22 branch.
>> 
>> Ian
>> 
>> 
>> 2011-09-27  Viktor Kutuzov  <vkutuzov@accesssoftek.com>
>> 	    Ian Lance Taylor  <iant@google.com>
>> 
>> 	* symtab.cc (Symbol_table::define_special_symbol): Always
>> 	canonicalize version string.
>> 
>>