From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:35636 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755553AbeDQQJB (ORCPT ); Tue, 17 Apr 2018 12:09:01 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Dan Hettena , Marc Zyngier , Will Deacon , Catalin Marinas , Greg Hackmann , Mark Rutland Subject: [PATCH 4.9 29/66] arm64: entry: Apply BP hardening for high-priority synchronous exceptions Date: Tue, 17 Apr 2018 17:59:02 +0200 Message-Id: <20180417155647.135110935@linuxfoundation.org> In-Reply-To: <20180417155645.868055442@linuxfoundation.org> References: <20180417155645.868055442@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mark Rutland From: Will Deacon commit 5dfc6ed27710c42cbc15db5c0d4475699991da0a upstream. Software-step and PC alignment fault exceptions have higher priority than instruction abort exceptions, so apply the BP hardening hooks there too if the user PC appears to reside in kernel space. Reported-by: Dan Hettena Reviewed-by: Marc Zyngier Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Mark Rutland [v4.9 backport] Tested-by: Greg Hackmann Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/entry.S | 6 ++++-- arch/arm64/mm/fault.c | 9 +++++++++ 2 files changed, 13 insertions(+), 2 deletions(-) --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -624,8 +624,10 @@ el0_sp_pc: * Stack or PC alignment exception handling */ mrs x26, far_el1 - // enable interrupts before calling the main handler - enable_dbg_and_irq + enable_dbg +#ifdef CONFIG_TRACE_IRQFLAGS + bl trace_hardirqs_off +#endif ct_user_exit mov x0, x26 mov x1, x25 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -617,6 +617,12 @@ asmlinkage void __exception do_sp_pc_abo struct siginfo info; struct task_struct *tsk = current; + if (user_mode(regs)) { + if (instruction_pointer(regs) > TASK_SIZE) + arm64_apply_bp_hardening(); + local_irq_enable(); + } + if (show_unhandled_signals && unhandled_signal(tsk, SIGBUS)) pr_info_ratelimited("%s[%d]: %s exception: pc=%p sp=%p\n", tsk->comm, task_pid_nr(tsk), @@ -676,6 +682,9 @@ asmlinkage int __exception do_debug_exce if (interrupts_enabled(regs)) trace_hardirqs_off(); + if (user_mode(regs) && instruction_pointer(regs) > TASK_SIZE) + arm64_apply_bp_hardening(); + if (!inf->fn(addr, esr, regs)) { rv = 1; } else {