x86/entry: Build thunk_$(BITS) only if CONFIG_PREEMPTION=y

stable inclusion
from stable-v5.10.137
commit a9943942a501114d5ea1093329e3b04da597b085
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a9943942a501114d5ea1093329e3b04da597b085

--------------------------------

[ Upstream commit de979c83 ]

With CONFIG_PREEMPTION disabled, arch/x86/entry/thunk_$(BITS).o becomes
an empty object file.

With some old versions of binutils (i.e., 2.35.90.20210113-1ubuntu1) the
GNU assembler doesn't generate a symbol table for empty object files and
objtool fails with the following error when a valid symbol table cannot
be found:

  arch/x86/entry/thunk_64.o: warning: objtool: missing symbol table

To prevent this from happening, build thunk_$(BITS).o only if
CONFIG_PREEMPTION is enabled.

BugLink: https://bugs.launchpad.net/bugs/1911359



Fixes: 320100a5 ("x86/entry: Remove the TRACE_IRQS cruft")
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/Ys/Ke7EWjcX+ZlXO@arighi-desktop


Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>