Copy relocations against protected symbols

H.J. Lu hjl.tools@gmail.com
Thu Dec 18 19:03:00 GMT 2014


Adding glibc.

On Thu, Dec 18, 2014 at 10:52 AM, Cary Coutant <ccoutant@google.com> wrote:
>> Should we simply disallow creating DSO with protected data on targets
>> with copy relocation?
>
> I don't think so. Protected symbols are useful, and their presence

As soon as they are used in executable, the program will misbehave.

> doesn't mean that a copy relocation will be needed. It would be pretty
> heavy-handed, since most targets do support copy relocations.
>

When you create libfoo.so with normal data, bar, it will link and
work fine with executable, x, which accesses bar.  But after
you change bar in libfoo.so to protected without relinking x, x will
misbehave and users may not have a clue what is going on.


-- 
H.J.



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