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[Bug target/44290] [4.5 Regression] arm linux kernel crahes when built with -fipa-sra, __naked attribute is broken



------- Comment #9 from rguenth at gcc dot gnu dot org  2010-05-29 11:42 -------
(In reply to comment #8)
> (In reply to comment #6)
> > I note that copypage-xscale.c:xscale_mc_copy_user_highpage() calls a __naked
> > function to do the bulk copy.  Converting that to a plain inline function
> > (changing 'pc' to 'lr' in the final instruction that restores the scrach regs),
> > does not prevent the crash.  So I suspect a plain C code miscompilation.
> 
> Actually that conversion away from __naked may have been flawed.  What I'm
> seeing is that r148981 causes gcc to clone the __naked function and change its
> calling conventions in ways that don't match the proper function call ABI. 
> This breaks the body of the __naked function which is just a big asm()
> statement.

Well.  The arm backend needs to mark the function as "used in non-visible
ways" then.  Thus this is a target bug.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
          Component|tree-optimization           |target
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2010-05-29 11:42:59
               date|                            |
            Summary|[4.5 Regression] arm linux  |[4.5 Regression] arm linux
                   |kernel crahes when built    |kernel crahes when built
                   |with -fipa-sra              |with -fipa-sra, __naked
                   |                            |attribute is broken


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44290


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