From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp07.in.ibm.com (e28smtp07.in.ibm.com [122.248.162.7]) (using TLSv1 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 60E891A1D98 for ; Wed, 26 Aug 2015 18:27:04 +1000 (AEST) Received: from /spool/local by e28smtp07.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 26 Aug 2015 13:57:01 +0530 Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id 33B50E0024 for ; Wed, 26 Aug 2015 13:56:25 +0530 (IST) Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay05.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t7Q8Qih751904598 for ; Wed, 26 Aug 2015 13:56:45 +0530 Received: from d28av05.in.ibm.com (localhost [127.0.0.1]) by d28av05.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t7Q8QfDG025381 for ; Wed, 26 Aug 2015 13:56:42 +0530 From: "Aneesh Kumar K.V" To: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, ryabinin.a.a@gmail.com Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, "Aneesh Kumar K.V" Subject: [PATCH V2 09/10] kasan: Prevent deadlock in kasan reporting Date: Wed, 26 Aug 2015 13:56:17 +0530 Message-Id: <1440577578-15813-10-git-send-email-aneesh.kumar@linux.vnet.ibm.com> In-Reply-To: <1440577578-15813-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1440577578-15813-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , We we end up calling kasan_report in real mode, our shadow mapping for even spinlock variable will show poisoned. This will result in us calling kasan_report_error with lock_report spin lock held. To prevent this disable kasan reporting when we are priting error w.r.t kasan. Signed-off-by: Aneesh Kumar K.V --- mm/kasan/report.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 79fbc5d14bd2..82b41eb83e43 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -185,6 +185,10 @@ void kasan_report_error(struct kasan_access_info *info) { unsigned long flags; + /* + * Make sure we don't end up in loop. + */ + kasan_disable_current(); spin_lock_irqsave(&report_lock, flags); pr_err("=================================" "=================================\n"); @@ -194,12 +198,17 @@ void kasan_report_error(struct kasan_access_info *info) pr_err("=================================" "=================================\n"); spin_unlock_irqrestore(&report_lock, flags); + kasan_enable_current(); } void kasan_report_user_access(struct kasan_access_info *info) { unsigned long flags; + /* + * Make sure we don't end up in loop. + */ + kasan_disable_current(); spin_lock_irqsave(&report_lock, flags); pr_err("=================================" "=================================\n"); @@ -212,6 +221,7 @@ void kasan_report_user_access(struct kasan_access_info *info) pr_err("=================================" "=================================\n"); spin_unlock_irqrestore(&report_lock, flags); + kasan_enable_current(); } void kasan_report(unsigned long addr, size_t size, -- 2.5.0