From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: Re: [PATCH v2 0/3] blk-cgroup: some cleanup Date: Fri, 7 Apr 2023 12:45:47 -0700 Message-ID: <63cf4e4f-764b-8634-b29f-30d45bed1ca5@acm.org> References: <20230406145050.49914-1-zhouchengming@bytedance.com> <1416b648-188f-873a-08b3-c8e8494ab1a7@kernel.dk> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: Content-Language: en-US In-Reply-To: <1416b648-188f-873a-08b3-c8e8494ab1a7@kernel.dk> List-ID: Content-Type: text/plain; charset="windows-1252"; format="flowed" To: Jens Axboe , Chengming Zhou , tj@kernel.org Cc: paolo.valente@linaro.org, josef@toxicpanda.com, linux-block@vger.kernel.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org On 4/7/23 11:44, Jens Axboe wrote: > On 4/7/23 12:41=E2=80=AFPM, Bart Van Assche wrote: >> On 4/6/23 07:50, Chengming Zhou wrote: >>> These are some cleanup patches of blk-cgroup. Thanks for review. >> >> With these patches applied, my kernel test VM crashes during boot. The f= ollowing crash disappears if I revert these patches: >> >> BUG: KASAN: null-ptr-deref in bio_associate_blkg_from_css+0x83/0x240 >=20 > Would be useful in the report to know where that is, as it doesn't include > the code output. Hi Jens, This is what gdb tells me about the crash address: $ gdb vmlinux (gdb) list *(bio_associate_blkg_from_css+0x83) 0xffffffff81856923 is in bio_associate_blkg_from_css (./include/linux/blkde= v.h:865). 860 int iocb_bio_iopoll(struct kiocb *kiocb, struct io_comp_batch *iob, 861 unsigned int flags); 862 863 static inline struct request_queue *bdev_get_queue(struct block_dev= ice *bdev) 864 { 865 return bdev->bd_queue; /* this is never NULL */ 866 } 867 868 /* Helper to convert BLK_ZONE_ZONE_XXX to its string format XXX */ 869 const char *blk_zone_cond_str(enum blk_zone_cond zone_cond); Thanks, Bart.