Keith Owens wrote:
> On Thu, 1 Aug 2002 07:20:36 -0400,
> Jim Houston <jim.houston@xxxxxxxxx> wrote:
> >Compiling the kdb with gcc 3.1 breaks kdba_setjmp. It seems
> >that gcc 3.1 is more clever about omiting frame pointers for
> >leaf functions. When it does this for kdba_setjmp it causes an
> >oops on entry to kdb.
> >
> >The attached patch uses the gcc built in functions to get the
> >frame pointer and the return adddress. This gets rid of the hard
> >coded stack offsets and should make it more portable.
>
> Does __builtin_frame_address work for older gcc, even if you compile
> the kernel without frame pointers? I vaguely remember that it returns
> garbage on older versions of gcc if ebp is not dedicated.
We've been seeing this kdb_setjmp oops on Red Hat 7.2 and Advanced
Server kernels when entering kdb via the Pause key. Both kernels
are built with gcc 2.96 and with -fomit-frame-pointer.
In any case, Jim's patch fixes the problem.
Dave Anderson
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