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 12:38:59 +0000 (14:38 +0200)
commit91335ca9ebe79f2c85e183d9e632044f71836d02
tree6e4d2d569ce0ed70fe03be666f63f81218a0cafe
parent49952e31e50d9d04a59cd08b958a08b0b81c4401
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