The call stack below shows how this happens: basically eager_fpu_init()
calls __thread_fpu_begin(current) which then does if (!use_eager_fpu()),
which, in turn, uses static_cpu_has.
And we're executing before alternatives so static_cpu_has doesn't work
there yet.
Use the safe variant in this path which becomes optimal after
alternatives have run.
WARNING: at arch/x86/kernel/cpu/common.c:1368 warn_pre_alternatives+0x1e/0x20()
You're using static_cpu_has before alternatives have run!
Modules linked in:
Pid: 0, comm: swapper Not tainted 3.9.0-rc8+ #1
Call Trace:
warn_slowpath_common
warn_slowpath_fmt
? fpu_finit
warn_pre_alternatives
eager_fpu_init
fpu_init
cpu_init
trap_init
start_kernel
? repair_env_string
x86_64_start_reservations
x86_64_start_kernel
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1370772454-6106-6-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
5f8c421814