------- Comment #6 from mikpe at it dot uu dot se 2010-05-28 11:49 ------- Confirmed. A linux-2.6.34 kernel configured for ARM and compiled with gcc-4.5-20100520 crashes during boot with a NULL pointer dereference in its copy_user_highpage() exactly at the point where it tries to start /sbin/init. HIGHMEM enabled or not makes no difference. The same kernel compiled with gcc-4.4.4 boots fine.
Both gcc's were configured for armv5tel-unknown-linux-gnu --with-arch=armv5te --with-tune=xscale. The linux kernels were built for mach-iop32x/n2100 (XScale IOP80219). 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. I'll try to bisect it. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44290
