question about env and function malloc

[Alexandre Oliva]

On Dec 19, 2014, Rich Felker <dalias@libc.org> wrote:

> On Thu, Dec 18, 2014 at 03:44:10AM -0200, Alexandre Oliva wrote:
>> [Cc:ing the list]
>> 
>> On Dec 17, 2014, MaShimiao <mashimiao.fnst@cn.fujitsu.com> wrote:
>> 
>> > But, the description of env in glibc manual says if a function accesses 
>> > environment with getenv() of similar, without any guard, then it should be
>> > marked with env. it doesn't mention any special functions.
>> > Do you think we should add some words to remind users that there are some special
>> > conditions in which even a function calls getenv(), it will not be marked with env.
>> > Just like malloc() or free().
>> > Or we just add explanations in the description of each special functions?
>> 
>> I think a note at the exception point should be enough, as in the patch
>> below.

> This is a conformance issue; for the purpose of safety with respect to
> modifying the environment in a multi-threaded program, the set of
> standard functions allowed to access the environment is fixed by POSIX
> and does not include malloc.

The “env” safety note quite often indicate deviations from the standard
anyway, so I don't see what light your statement sheds on the issue at
hand.  Can you please elaborate?  TIA,

-- 
Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer