[Bug target/55431] Invalid auxv search in ppc linux-unwind code.

[bugdal at aerifal dot cx]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55431

--- Comment #8 from Rich Felker <bugdal at aerifal dot cx> 2013-02-12 15:27:58 UTC ---
Is there nothing internal in the sigcontext structure that distinguishes the
version?

Making the reference to __libc_stack_end weak won't help. If the symbol is
undefined, the code in libgcc would crash or malfunction; if it's defined but
does not point exactly to the argc/argv start (which, since it's not defined in
the ABI, seems to be something that could happen in the future even with
glibc), the code will also badly malfunction.

If you want to keep using __libc_stack_end, I think it should be conditional at
runtime on old/broken kernel and libc versions, and auxv should be ignored
otherwise.