[PATCH roland/arm-mcount] ARM: Disable compat mcount code when unneeded.

[Joseph S. Myers]

On Fri, 10 Jan 2014, Roland McGrath wrote:

> I've done an arm-linux-gnueabi build and verified that arm-mcount.o{,s}
> have no differences except for the addition of the __mcount_arm_compat
> symbol, and that 'make check-abi' still passes.
> 
> I've done an arm-linux-gnueabihf build and verified that arm-mcount.o has
> no differences except the removal of the _mcount code and the mcount alias,
> and that arm-mcount.os has no differences except in its symbol table, and
> that 'make check-abi' still passes.  That is, the one user-visible change
> here is that the symbols _mcount and mcount are no longer available at link
> time (either static or dynamic) for arm-linux-gnueabihf.  Does that merit a
> NEWS mention?

I don't think a NEWS mention is needed; making symbols no longer available 
at link time should get a mention if users might have used them directly, 
but I don't see a need where the symbols couldn't sensibly have been 
called directly from user C code.

The change is OK with me for 2.19, since there's still another ARM issue 
pending before doing ARM release testing for 2.19.

-- 
Joseph S. Myers
joseph@codesourcery.com