From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jiang Liu , Jiang Liu , Catalin Marinas , Mark Brown Subject: [PATCH 3.10 122/129] arm64: fix possible invalid FPSIMD initialization state Date: Mon, 6 Jan 2014 14:39:11 -0800 Message-Id: <20140106223903.083057736@linuxfoundation.org> In-Reply-To: <20140106223859.589799655@linuxfoundation.org> References: <20140106223859.589799655@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiang Liu commit 6db83cea1c975b9a102e17def7d2795814e1ae2b upstream. If context switching happens during executing fpsimd_flush_thread(), stale value in FPSIMD registers will be saved into current thread's fpsimd_state by fpsimd_thread_switch(). That may cause invalid initialization state for the new process, so disable preemption when executing fpsimd_flush_thread(). Signed-off-by: Jiang Liu Cc: Jiang Liu Signed-off-by: Catalin Marinas Cc: Mark Brown Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/fpsimd.c | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -79,8 +79,10 @@ void fpsimd_thread_switch(struct task_st void fpsimd_flush_thread(void) { + preempt_disable(); memset(¤t->thread.fpsimd_state, 0, sizeof(struct fpsimd_state)); fpsimd_load_state(¤t->thread.fpsimd_state); + preempt_enable(); } /*