xtensa: patch_text: Fixup last cpu should be master
authorGuo Ren <guoren@linux.alibaba.com>
Thu, 7 Apr 2022 07:33:22 +0000 (15:33 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 27 Apr 2022 12:41:14 +0000 (14:41 +0200)
commit37ce27cbaf1ee74eeb5b6da35857bff99c901b6e
tree50b751551b8ba28ffb4c5ef1bf90b336bf3c571d
parenta6b48566dcceef635179d2c04c689da3d8e7191a
xtensa: patch_text: Fixup last cpu should be master

commit ee69d4be8fd064cd08270b4808d2dfece3614ee0 upstream.

These patch_text implementations are using stop_machine_cpuslocked
infrastructure with atomic cpu_count. The original idea: When the
master CPU patch_text, the others should wait for it. But current
implementation is using the first CPU as master, which couldn't
guarantee the remaining CPUs are waiting. This patch changes the
last CPU as the master to solve the potential risk.

Fixes: 64711f9a47d4 ("xtensa: implement jump_label support")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: <stable@vger.kernel.org>
Message-Id: <20220407073323.743224-4-guoren@kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/xtensa/kernel/jump_label.c