Subject: Re: next: kernel BUG at drivers/virtio/virtio.c:122!

From: Marek Szyprowski <[email-masked]>
Date: Tue, 20 Dec 2022 14:17:45 +0100

On 20.12.2022 11:54, Michael S. Tsirkin wrote:
> On Tue, Dec 20, 2022 at 06:27:59PM +0800, Xuan Zhuo wrote:
>> On Tue, 20 Dec 2022 14:51:54 +0530, Naresh Kamboju <[email-masked]> wrote:
>>> The qemu-x86_64 and qemu-arm64 boot failed with Linux next-20221220 tag.
>>> It is always reproducible with gcc-11/ gcc-12 and clang tool chains.
>>>
>>> Reported-by: Linux Kernel Functional Testing <[email-masked]>
>>>
>>> <6>[    0.000000] Booting Linux on physical CPU 0x0000000000 [0x000f0510]
>>> <5>[    0.000000] Linux version 6.1.0-next-20221220 (tuxmake@tuxmake)
>>> (Debian clang version 16.0.0
>>> (++20221218072110+9c1b82599dac-1~exp1~20221218072217.501), Debian LLD
>>> 16.0.0) #1 SMP PREEMPT @1671498176
>>> <5>[    0.000000] random: crng init done
>>> <6>[    0.000000] Machine model: linux,dummy-virt
>>> ....
>>> <6>[    3.571098] loop: module loaded
>>> <6>[    3.573410] virtio_blk virtio0: 1/0/0 default/read/poll queues
>>> <5>[    3.578816] virtio_blk virtio0: [vda] 2816420 512-byte logical
>>> blocks (1.44 GB/1.34 GiB)
>>> <4>[    3.581234] ------------[ cut here ]------------
>>> <2>[    3.581595] kernel BUG at drivers/virtio/virtio.c:122!
>>> <0>[    3.582906] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
>>> <4>[    3.583672] Modules linked in:
>>> <4>[    3.584905] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
>>> 6.1.0-next-20221220 #1
>>> <4>[    3.585801] Hardware name: linux,dummy-virt (DT)
>>> <4>[    3.586591] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT
>>> -SSBS BTYPE=--)
>>> <4>[    3.587349] pc : virtio_check_driver_offered_feature+0x60/0x6c
>>> <4>[    3.588613] lr : virtblk_probe+0x7cc/0x8f0
>>> <4>[    3.588915] sp : ffff80000802b840
>>> <4>[    3.589314] x29: ffff80000802b850 x28: 0000000000000000 x27:
>>> 0000000000000001
>>> <4>[    3.590509] x26: 0000000000000001 x25: 0000000000000200 x24:
>>> ffff0000c1699b00
>>> <4>[    3.590832] x23: 00000000000000fe x22: ffff0000c0313c30 x21:
>>> ffff0000c0313c00
>>> <4>[    3.591568] x20: ffff0000c02f4080 x19: 0000000000000000 x18:
>>> ffffffffffffffff
>>> <4>[    3.592056] x17: 00000000ffffffea x16: 00000000fffffffe x15:
>>> 0000000000000004
>>> <4>[    3.592632] x14: 0000000000000fff x13: ffff800008028000 x12:
>>> ffff80000802c000
>>> <4>[    3.593157] x11: 000000000000000f x10: 000000000000000f x9 :
>>> ffffae66eee314d8
>>> <4>[    3.594048] x8 : 0000000000000000 x7 : 3631383837352e33 x6 :
>>> 202020205b3e353c
>>> <4>[    3.594429] x5 : 0000000000000001 x4 : 0000000000000000 x3 :
>>> ffff80000802b780
>>> <4>[    3.594956] x2 : ffff80000802b6f8 x1 : 0000000000000011 x0 :
>>> ffff0000c02f4080
>>> <4>[    3.595811] Call trace:
>>> <4>[    3.596120]  virtio_check_driver_offered_feature+0x60/0x6c
>>> <4>[    3.596632]  virtio_dev_probe+0x274/0x320
>>> <4>[    3.597064]  really_probe+0x178/0x418
>>> <4>[    3.597547]  __driver_probe_device+0x120/0x188
>>> <4>[    3.597820]  driver_probe_device+0x48/0x22c
>>> <4>[    3.598189]  __driver_attach+0xf8/0x250
>>> <4>[    3.598656]  bus_for_each_dev+0x8c/0xd8
>>> <4>[    3.599151]  driver_attach+0x30/0x3c
>>> <4>[    3.599321]  bus_add_driver+0x11c/0x22c
>>> <4>[    3.599684]  driver_register+0x84/0x120
>>> <4>[    3.600175]  register_virtio_driver+0x38/0x48
>>> <4>[    3.600575]  virtio_blk_init+0x6c/0xb4
>>> <4>[    3.600759]  do_one_initcall+0xe0/0x2f8
>>> <4>[    3.601197]  do_initcall_level+0xa8/0x150
>>> <4>[    3.601703]  do_initcalls+0x60/0xa0
>>> <4>[    3.601892]  do_basic_setup+0x28/0x34
>>> <4>[    3.602229]  kernel_init_freeable+0x100/0x178
>>> <4>[    3.602706]  kernel_init+0x2c/0x1b4
>>> <4>[    3.603162]  ret_from_fork+0x10/0x20
>>> <0>[    3.604398] Code: 540000a0 91001129 f1000508 54ffff61 (d4210000)
>>> <4>[    3.606108] ---[ end trace 0000000000000000 ]---
>>> <6>[    3.606714] note: swapper/0[1] exited with preempt_count 1
>>> <0>[    3.608155] Kernel panic - not syncing: Attempted to kill init!
>>> exitcode=0x0000000b
>>> <2>[    3.609173] SMP: stopping secondary CPUs
>>> <0>[    3.610506] Kernel Offset: 0x2e66e4800000 from 0xffff800008000000
>>> <0>[    3.610970] PHYS_OFFSET: 0x40000000
>>> <0>[    3.611428] CPU features: 0x00000,003a612f,cd22773f
>>> <0>[    3.612277] Memory Limit: none
>>> <0>[    3.613192] ---[ end Kernel panic - not syncing: Attempted to
>>> kill init! exitcode=0x0000000b ]---
>>>
>>> Ref Links,
>>> https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20221220/testrun/13764099/suite/log-parser-test/test/check-kernel-bug/details/
>>> https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20221220/testrun/13766814/suite/boot/test/clang-nightly-lkftconfig/details/
>>> https://storage.tuxsuite.com/public/linaro/lkft/builds/2J9l3qxSBmPWVa1S2uWn0Xuwl1J/config
>>>
>>
>> I think there is a bug, VIRTIO_BLK_F_ZONED depends the CONFIG_BLK_DEV_ZONE, but
>> checking its code in virtblk_probe does not depend on this config.
>>
>> This option in your config file is indeed not opened.
>>
>>
>> static int virtblk_probe(struct virtio_device *vdev){
>> .....
>> 	virtblk_update_capacity(vblk, false);
>> 	virtio_device_ready(vdev);
>>
>> 	if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) {
>> 		err = virtblk_probe_zoned_device(vdev, vblk, q);
>> 		if (err)
>> 			goto out_cleanup_disk;
>> 	}
>>
>> 	dev_info(&vdev->dev, "blk config size: %zu\n",
>> 		sizeof(struct virtio_blk_config));
>>
>> ....
>>
>> static unsigned int features[] = {
>> 	VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
>> 	VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
>> 	VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
>> 	VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
>> 	VIRTIO_BLK_F_SECURE_ERASE, VIRTIO_BLK_F_LIFETIME,
>> #ifdef CONFIG_BLK_DEV_ZONED
>> 	VIRTIO_BLK_F_ZONED,
>> #endif /* CONFIG_BLK_DEV_ZONED */
>> }
>>
>>
>> Thanks.
> Oh you are right, I wanted to test it so of course I enabled it.
>
> Testing this fixup now:
>
> commit f9503d0fd839b59e0f48b00c20635437c41420ed
> Author: Michael S. Tsirkin <[email-masked]>
> Date:   Tue Dec 20 05:53:41 2022 -0500
>
>      fixup! virtio-blk: add support for zoned block devices

I also confirm that this patch fixes the issue with broken virtio block 
device observed on QEMU arm/arm64 'virt' machines and linux 
next-20221220. Thanks for the fix!

Tested-by: Marek Szyprowski <[email-masked]>

> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index ff49052e26f7..d8cdaeb51d1c 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -775,6 +775,10 @@ static int virtblk_probe_zoned_device(struct virtio_device *vdev,
>   	return ret;
>   }
>   
> +static inline bool virtblk_has_zoned_feature(struct virtio_device *vdev)
> +{
> +	return virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED);
> +}
>   #else
>   
>   /*
> @@ -790,6 +794,11 @@ static inline int virtblk_probe_zoned_device(struct virtio_device *vdev,
>   {
>   	return -EOPNOTSUPP;
>   }
> +
> +static inline bool virtblk_has_zoned_feature(struct virtio_device *vdev)
> +{
> +	return false;
> +}
>   #endif /* CONFIG_BLK_DEV_ZONED */
>   
>   /* return id (s/n) string for *disk to *id_str
> @@ -1576,11 +1585,11 @@ static int virtblk_probe(struct virtio_device *vdev)
>   		else
>   			q->limits.discard_granularity = blk_size;
>   	}
>   
>   	virtblk_update_capacity(vblk, false);
>   	virtio_device_ready(vdev);
>   
> -	if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) {
> +	if (virtblk_has_zoned_feature(vdev)) {
>   		err = virtblk_probe_zoned_device(vdev, vblk, q);
>   		if (err)
>   			goto out_cleanup_disk;

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland