Warning: requires executable stack...

Warning: requires executable stack...

[reinert]

Hello,

I use alire and I just updated via these commands:

alr index --update-all
alr toolchain --select

(selected 
gnat_native=12.2.1
and 
gprbuild=22.0.1
)

All seem OK, but when I use "alr build" I finally get this warning:

...../.config/alire/cache/dependencies/gnat_native_12.2.1_11f3b811/bin/../lib/gcc/x86_64-pc-linux-gnu/12.2.0/../../../../x86_64-pc-linux-gnu/bin/ld: warning: kobio0.o: requires executable stack (because the .note.GNU-stack section is executable)
Build finished successfully in 19.48 seconds.

When trying a simple "hello_world" programme, I do not get this annoying warning.

Any hint?
I do not like warnings which I do not understand anything from :-)

reinert

Re: Warning: requires executable stack...

[Simon Wright]

reinert <reinkor@gmail.com> writes:

> ...../.config/alire/cache/dependencies/gnat_native_12.2.1_11f3b811/bin/../lib/gcc/x86_64-pc-linux-gnu/12.2.0/../../../../x86_64-pc-linux-gnu/bin/ld:
> warning: kobio0.o: requires executable stack (because the
> .note.GNU-stack section is executable)

Creating executable code on the stack is one way of getting malicious
code past virus checkers. Modern OSs will prevent this approach.

So far as I know, GNAT will only do this to implement "trampolines", but see
here:
https://docs.adacore.com/live/wave/gnat_rm/html/gnat_rm/gnat_rm/standard_and_implementation_defined_restrictions.html#no-implicit-dynamic-code

Re: Warning: requires executable stack...

[reinert]

Thanks for swift answer.  Seems like I have to live with the warning. 

I learned about pragma restrictions(...);  :-)

reinert


fredag 28. april 2023 kl. 09:26:20 UTC+2 skrev Simon Wright:
> reinert <rei...@gmail.com> writes: 
> 
> > ...../.config/alire/cache/dependencies/gnat_native_12.2.1_11f3b811/bin/../lib/gcc/x86_64-pc-linux-gnu/12.2.0/../../../../x86_64-pc-linux-gnu/bin/ld: 
> > warning: kobio0.o: requires executable stack (because the 
> > .note.GNU-stack section is executable)
> Creating executable code on the stack is one way of getting malicious 
> code past virus checkers. Modern OSs will prevent this approach. 
> 
> So far as I know, GNAT will only do this to implement "trampolines", but see 
> here: 
> https://docs.adacore.com/live/wave/gnat_rm/html/gnat_rm/gnat_rm/standard_and_implementation_defined_restrictions.html#no-implicit-dynamic-code