Does dladdr1 allocate heap memory?

Does dladdr1 allocate heap memory?

[Ponnuvel Palaniyappan]

Hi,

I have a custom dlsym-like symbol resolver (dlsym allocates memory on
failure which causes problem when using my
code alongside malloc interposing libraries). Getting the struct link_map
is one of the steps and I am wondering
if I can make use of dladdr1 for that purpose. That obviously requires
dladdr1 to *not* allocate heap memory.
In my testing, it appears be heap-alloc-safe. But I am wondering if there
are any edge cases where it might not be so.

Thanks.

Re: Does dladdr1 allocate heap memory?

[Florian Weimer]

On 11/10/2017 07:52 PM, Ponnuvel Palaniyappan wrote:
> Getting the struct link_map
> is one of the steps and I am wondering
> if I can make use of dladdr1 for that purpose.

I double-checked the situation, and dladdr1 will not call malloc in case 
of an error, so you should be good.

(The code does not even install the ld.so exception handler, so it would 
not be able to catch errors anyway.)

Florian

Re: Does dladdr1 allocate heap memory?

[Ponnuvel Palaniyappan]

Thanks a lot!

On 10-Nov-2017 9:07 pm, "Florian Weimer" <fweimer@redhat.com> wrote:

> On 11/10/2017 07:52 PM, Ponnuvel Palaniyappan wrote:
>
>> Getting the struct link_map
>> is one of the steps and I am wondering
>> if I can make use of dladdr1 for that purpose.
>>
>
> I double-checked the situation, and dladdr1 will not call malloc in case
> of an error, so you should be good.
>
> (The code does not even install the ld.so exception handler, so it would
> not be able to catch errors anyway.)
>
> Florian
>