These compiler versions are known to miscompile __weak functions and
thus generate kernels that don't necessarily work correctly. If a weak
function is int he same compilation unit as a caller, gcc may end up
inlining it, and thus binding the weak function too early.
See
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27781
for details.
Cc: Adrian Bunk <bunk@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>