From patchwork Thu Sep 15 13:49:07 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 9333693 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B6D1C6077A for ; Thu, 15 Sep 2016 13:50:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9E457297BB for ; Thu, 15 Sep 2016 13:50:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8DF91297BE; Thu, 15 Sep 2016 13:50:43 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 82704297BB for ; Thu, 15 Sep 2016 13:50:42 +0000 (UTC) Received: (qmail 13482 invoked by uid 550); 15 Sep 2016 13:50:21 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: kernel-hardening@lists.openwall.com Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 12258 invoked from network); 15 Sep 2016 13:50:19 -0000 From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Cc: akpm@linux-foundation.org, ard.biesheuvel@linaro.org, catalin.marinas@arm.com, james.morse@arm.com, keescook@chromium.org, linux-kernel@vger.kernel.org, lorenzo.pieralisi@arm.com, luto@kernel.org, mark.rutland@arm.com, suzuki.poulose@arm.com, takahiro.akashi@linaro.org, will.deacon@arm.com, kernel-hardening@lists.openwall.com Date: Thu, 15 Sep 2016 14:49:07 +0100 Message-Id: <1473947349-14521-7-git-send-email-mark.rutland@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1473947349-14521-1-git-send-email-mark.rutland@arm.com> References: <1473947349-14521-1-git-send-email-mark.rutland@arm.com> Subject: [kernel-hardening] [RFC PATCH 6/8] arm64: traps: use task_struct instead of thread_info X-Virus-Scanned: ClamAV using ClamSMTP In arm64's die and __die routines we pass around a thread_info, and subsequently use this to determine either the relevant task_struct, or the end of the thread's stack. This will shortly become problematic when we move the thread_info out of the thread's stack. Instead, pass around the task_struct, and use the new end_of_stack helper, which will work regardless of where thread_info is located. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon --- arch/arm64/kernel/traps.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index e04f838..e9409a9 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -227,10 +227,9 @@ void show_stack(struct task_struct *tsk, unsigned long *sp) #endif #define S_SMP " SMP" -static int __die(const char *str, int err, struct thread_info *thread, +static int __die(const char *str, int err, struct task_struct *tsk, struct pt_regs *regs) { - struct task_struct *tsk = thread->task; static int die_counter; int ret; @@ -245,7 +244,8 @@ static int __die(const char *str, int err, struct thread_info *thread, print_modules(); __show_regs(regs); pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n", - TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1); + TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), + end_of_stack(tsk)); if (!user_mode(regs)) { dump_mem(KERN_EMERG, "Stack: ", regs->sp, @@ -264,7 +264,7 @@ static DEFINE_RAW_SPINLOCK(die_lock); */ void die(const char *str, struct pt_regs *regs, int err) { - struct thread_info *thread = current_thread_info(); + struct task_struct *tsk = current; int ret; oops_enter(); @@ -272,9 +272,9 @@ void die(const char *str, struct pt_regs *regs, int err) raw_spin_lock_irq(&die_lock); console_verbose(); bust_spinlocks(1); - ret = __die(str, err, thread, regs); + ret = __die(str, err, tsk, regs); - if (regs && kexec_should_crash(thread->task)) + if (regs && kexec_should_crash(tsk)) crash_kexec(regs); bust_spinlocks(0);