From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:56658 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966782AbeEXJp3 (ORCPT ); Thu, 24 May 2018 05:45:29 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Masami Hiramatsu , Russell King Subject: [PATCH 4.4 65/92] ARM: 8769/1: kprobes: Fix to use get_kprobe_ctlblk after irq-disabed Date: Thu, 24 May 2018 11:38:42 +0200 Message-Id: <20180524093205.539658174@linuxfoundation.org> In-Reply-To: <20180524093159.286472249@linuxfoundation.org> References: <20180524093159.286472249@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masami Hiramatsu commit 69af7e23a6870df2ea6fa79ca16493d59b3eebeb upstream. Since get_kprobe_ctlblk() uses smp_processor_id() to access per-cpu variable, it hits smp_processor_id sanity check as below. [ 7.006928] BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1 [ 7.007859] caller is debug_smp_processor_id+0x20/0x24 [ 7.008438] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.16.0-rc1-00192-g4eb17253e4b5 #1 [ 7.008890] Hardware name: Generic DT based system [ 7.009917] [] (unwind_backtrace) from [] (show_stack+0x20/0x24) [ 7.010473] [] (show_stack) from [] (dump_stack+0x84/0x98) [ 7.010990] [] (dump_stack) from [] (check_preemption_disabled+0x138/0x13c) [ 7.011592] [] (check_preemption_disabled) from [] (debug_smp_processor_id+0x20/0x24) [ 7.012214] [] (debug_smp_processor_id) from [] (optimized_callback+0x2c/0xe4) [ 7.013077] [] (optimized_callback) from [] (0xbf0021b0) To fix this issue, call get_kprobe_ctlblk() right after irq-disabled since that disables preemption. Fixes: 0dc016dbd820 ("ARM: kprobes: enable OPTPROBES for ARM 32") Signed-off-by: Masami Hiramatsu Cc: stable@vger.kernel.org Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman --- arch/arm/probes/kprobes/opt-arm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/arm/probes/kprobes/opt-arm.c +++ b/arch/arm/probes/kprobes/opt-arm.c @@ -165,13 +165,14 @@ optimized_callback(struct optimized_kpro { unsigned long flags; struct kprobe *p = &op->kp; - struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + struct kprobe_ctlblk *kcb; /* Save skipped registers */ regs->ARM_pc = (unsigned long)op->kp.addr; regs->ARM_ORIG_r0 = ~0UL; local_irq_save(flags); + kcb = get_kprobe_ctlblk(); if (kprobe_running()) { kprobes_inc_nmissed_count(&op->kp);