From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id 79BC36B000E for ; Wed, 25 Apr 2018 17:11:15 -0400 (EDT) Received: by mail-pf0-f200.google.com with SMTP id k3so16642650pff.23 for ; Wed, 25 Apr 2018 14:11:15 -0700 (PDT) Received: from bombadil.infradead.org (bombadil.infradead.org. [2607:7c80:54:e::133]) by mx.google.com with ESMTPS id e125si16020385pfe.244.2018.04.25.14.11.14 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 25 Apr 2018 14:11:14 -0700 (PDT) Subject: Re: [PATCH v5] fault-injection: introduce kvmalloc fallback options References: <20180421144757.GC14610@bombadil.infradead.org> <20180423151545.GU17484@dhcp22.suse.cz> <20180424125121.GA17484@dhcp22.suse.cz> <20180424162906.GM17484@dhcp22.suse.cz> <20180424170349.GQ17484@dhcp22.suse.cz> <20180424173836.GR17484@dhcp22.suse.cz> <1114eda5-9b1f-4db8-2090-556b4a37c532@infradead.org> From: Randy Dunlap Message-ID: Date: Wed, 25 Apr 2018 14:11:06 -0700 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mikulas Patocka Cc: Michal Hocko , Matthew Wilcox , David Miller , Andrew Morton , linux-mm@kvack.org, eric.dumazet@gmail.com, edumazet@google.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, dm-devel@redhat.com, Vlastimil Babka On 04/25/2018 01:57 PM, Mikulas Patocka wrote: > > > On Wed, 25 Apr 2018, Randy Dunlap wrote: > >> On 04/25/2018 01:02 PM, Mikulas Patocka wrote: >>> >>> >>> From: Mikulas Patocka >>> Subject: [PATCH v4] fault-injection: introduce kvmalloc fallback options >>> >>> This patch introduces a fault-injection option "kvmalloc_fallback". This >>> option makes kvmalloc randomly fall back to vmalloc. >>> >>> Unfortunatelly, some kernel code has bugs - it uses kvmalloc and then >> >> Unfortunately, > > OK - here I fixed the typos: > > > From: Mikulas Patocka > Subject: [PATCH] fault-injection: introduce kvmalloc fallback options > > This patch introduces a fault-injection option "kvmalloc_fallback". This > option makes kvmalloc randomly fall back to vmalloc. > > Unfortunately, some kernel code has bugs - it uses kvmalloc and then > uses DMA-API on the returned memory or frees it with kfree. Such bugs were > found in the virtio-net driver, dm-integrity or RHEL7 powerpc-specific > code. This options helps to test for these bugs. > > The patch introduces a config option FAIL_KVMALLOC_FALLBACK_PROBABILITY. > It can be enabled in distribution debug kernels, so that kvmalloc abuse > can be tested by the users. The default can be overridden with > "kvmalloc_fallback" parameter or in /sys/kernel/debug/kvmalloc_fallback/. > > Signed-off-by: Mikulas Patocka > > --- > Documentation/fault-injection/fault-injection.txt | 7 +++++ > include/linux/fault-inject.h | 9 +++--- > kernel/futex.c | 2 - > lib/Kconfig.debug | 15 +++++++++++ > mm/failslab.c | 2 - > mm/page_alloc.c | 2 - > mm/util.c | 30 ++++++++++++++++++++++ > 7 files changed, 60 insertions(+), 7 deletions(-) Acked-by: Randy Dunlap # Documentation and Kconfig only thanks. -- ~Randy