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 11:53:55 +0000 (13:53 +0200)
commitf399ab11dd6cc0a6927029371fbe2ec027181598
treef3791c00843113c97987baaa4bff582079ae2c75
parentba2716da233618c3f361b8ece818a0e91de7a8f0
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