On Wed, 8 Feb 2023 at 08:32, Christian König <christian.koenig@xxxxxxx> wrote:
>
> Hey guys,
>
> I'm pretty sure this is a bug in bochs which happens to surface because
> of a recent TTM change, we have seen similar problems in the past with
> this driver.
>
> What happens is that userspace tries to bind a BO to a CRTC before the
> BO has even a backing store.
>
> Any idea how to fix this? I can just remove the warning, but that's not
> really a good solution.
IIUC this driver is just using ttm_bo_move_memcpy() underneath for its
bo_move callback, which looks to be doing:
if (!bo->resource)
return 0;
Which doesn't make any sense to me.There should at least be a
move_null(), and maybe also a multi-hop to handle clearing. Otherwise
bo->resource is likely always NULL (and we hit the above warning),
even after the dummy move. What do you think?
>
> Regards,
> Christian.
>
> Am 08.02.23 um 05:32 schrieb kernel test robot:
> > Greeting,
> >
> > FYI, we noticed WARNING:at_drivers/gpu/drm/drm_gem_vram_helper.c:#drm_gem_vram_offset due to commit (built with gcc-11):
> >
> > commit: 1802537820389183dfcd814e0f6a60d1496a75ef ("drm/ttm: stop allocating dummy resources during BO creation")
> > git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
> >
> > in testcase: boot
> >
> > on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
> >
> > caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
> >
> >
> > If you fix the issue, kindly add following tag
> > | Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
> > | Link: https://lore.kernel.org/oe-lkp/202302081038.984b8c1-oliver.sang@xxxxxxxxx
> >
> >
> > [ 25.994992][ T1] ------------[ cut here ]------------
> > [ 25.995050][ T1] WARNING: CPU: 0 PID: 1 at drivers/gpu/drm/drm_gem_vram_helper.c:255 drm_gem_vram_offset (??:?)
> > [ 25.995080][ T1] Modules linked in:
> > [ 25.995100][ T1] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G T 6.2.0-rc6-01191-g180253782038 #1 a8db67375c3ac749313dafaec43f39836e38fae9
> > [ 25.995117][ T1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-5 04/01/2014
> > [ 25.995128][ T1] RIP: 0010:drm_gem_vram_offset (??:?)
> > [ 25.995144][ T1] Code: 02 00 00 b8 ff ff 37 00 48 89 fa 48 c1 e0 2a 48 c1 ea 03 80 3c 02 00 74 05 e8 7f 1f eb fe 48 8b 9b 20 02 00 00 48 85 db 75 06 <0f> 0b 31 c0 eb 4b 48 8d 7b 10 b8 ff ff 37 00 48 89 fa 48 c1 e0 2a
> > All code
> > ========
> > 0: 02 00 add (%rax),%al
> > 2: 00 b8 ff ff 37 00 add %bh,0x37ffff(%rax)
> > 8: 48 89 fa mov %rdi,%rdx
> > b: 48 c1 e0 2a shl $0x2a,%rax
> > f: 48 c1 ea 03 shr $0x3,%rdx
> > 13: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
> > 17: 74 05 je 0x1e
> > 19: e8 7f 1f eb fe callq 0xfffffffffeeb1f9d
> > 1e: 48 8b 9b 20 02 00 00 mov 0x220(%rbx),%rbx
> > 25: 48 85 db test %rbx,%rbx
> > 28: 75 06 jne 0x30
> > 2a:* 0f 0b ud2 <-- trapping instruction
> > 2c: 31 c0 xor %eax,%eax
> > 2e: eb 4b jmp 0x7b
> > 30: 48 8d 7b 10 lea 0x10(%rbx),%rdi
> > 34: b8 ff ff 37 00 mov $0x37ffff,%eax
> > 39: 48 89 fa mov %rdi,%rdx
> > 3c: 48 c1 e0 2a shl $0x2a,%rax
> >
> > Code starting with the faulting instruction
> > ===========================================
> > 0: 0f 0b ud2
> > 2: 31 c0 xor %eax,%eax
> > 4: eb 4b jmp 0x51
> > 6: 48 8d 7b 10 lea 0x10(%rbx),%rdi
> > a: b8 ff ff 37 00 mov $0x37ffff,%eax
> > f: 48 89 fa mov %rdi,%rdx
> > 12: 48 c1 e0 2a shl $0x2a,%rax
> > [ 25.995156][ T1] RSP: 0000:ffffc9000001f028 EFLAGS: 00210246
> > [ 25.995174][ T1] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
> > [ 25.995186][ T1] RDX: 1ffff11026dee544 RSI: ffff8881372d4b10 RDI: ffff888136f72a20
> > [ 25.995196][ T1] RBP: ffffc9000001f030 R08: 0000000000000000 R09: 0000000000000000
> > [ 25.995206][ T1] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881372d4b00
> > [ 25.995215][ T1] R13: ffff888136e9ee00 R14: ffff888136f4a060 R15: 0000000000000500
> > [ 25.995225][ T1] FS: 0000000000000000(0000) GS:ffff8883aee00000(0000) knlGS:0000000000000000
> > [ 25.995236][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [ 25.995247][ T1] CR2: 00000000f7fa1cd4 CR3: 0000000006015000 CR4: 00000000000406b0
> > [ 25.995262][ T1] Call Trace:
> > [ 25.995271][ T1] <TASK>
> > [ 25.995287][ T1] bochs_plane_update (bochs.c:?)
> > [ 25.995308][ T1] ? rcu_read_lock_bh_held (??:?)
> > [ 25.995337][ T1] ? bochs_pci_probe (bochs.c:?)
> > [ 25.995352][ T1] ? srcu_read_unlock (blk-mq.c:?)
> > [ 25.995396][ T1] bochs_pipe_enable (bochs.c:?)
> > [ 25.995410][ T1] ? drm_dev_printk (??:?)
> > [ 25.995435][ T1] ? bochs_pipe_update (bochs.c:?)
> > [ 25.995454][ T1] ? bochs_plane_update (bochs.c:?)
> > [ 25.995473][ T1] ? bochs_pipe_update (bochs.c:?)
> > [ 25.995487][ T1] ? bochs_pipe_update (bochs.c:?)
> > [ 25.995507][ T1] drm_simple_kms_crtc_enable (drm_simple_kms_helper.c:?)
> > [ 25.995533][ T1] drm_atomic_helper_commit_modeset_enables (??:?)
> > [ 25.995570][ T1] drm_atomic_helper_commit_tail (??:?)
> > [ 25.995591][ T1] commit_tail (drm_atomic_helper.c:?)
> > [ 25.995631][ T1] drm_atomic_helper_commit (??:?)
> > [ 25.995652][ T1] ? commit_work (??:?)
> > [ 25.995670][ T1] drm_atomic_commit (??:?)
> > [ 25.995689][ T1] ? drm_atomic_nonblocking_commit (??:?)
> > [ 25.995703][ T1] ? __drm_atomic_helper_set_config (??:?)
> > [ 25.995716][ T1] ? malformed_message+0xe0/0xe0
> > [ 25.995741][ T1] ? update_output_state (??:?)
> > [ 25.995757][ T1] ? malformed_message+0xe0/0xe0
> > [ 25.995804][ T1] drm_client_modeset_commit_atomic (drm_client_modeset.c:?)
> > [ 25.995836][ T1] ? kmalloc_array (core.c:?)
> > [ 25.995894][ T1] ? mutex_trylock (mutex.c:?)
> > [ 25.995910][ T1] ? mark_lock+0x67/0x227
> > [ 25.995951][ T1] ? drm_fb_helper_lastclose (??:?)
> > [ 25.995966][ T1] drm_client_modeset_commit_locked (??:?)
> > [ 25.995988][ T1] drm_client_modeset_commit (??:?)
> > [ 25.996008][ T1] __drm_fb_helper_restore_fbdev_mode_unlocked (drm_fb_helper.c:?)
> > [ 25.996032][ T1] drm_fb_helper_set_par (??:?)
> > [ 25.996054][ T1] set_con2fb_map (fbcon.c:?)
> > [ 25.996090][ T1] do_fb_registered (fbcon.c:?)
> > [ 25.996119][ T1] fbcon_fb_registered (??:?)
> > [ 25.996138][ T1] do_register_framebuffer (fbmem.c:?)
> > [ 25.996158][ T1] ? get_fb_info+0xaa/0xaa
> > [ 25.996218][ T1] register_framebuffer (??:?)
> > [ 25.996241][ T1] __drm_fb_helper_initial_config_and_unlock (drm_fb_helper.c:?)
> > [ 25.996268][ T1] ? __drm_fb_helper_find_sizes (drm_fb_helper.c:?)
> > [ 25.996321][ T1] drm_fb_helper_initial_config (??:?)
> > [ 25.996341][ T1] drm_fbdev_client_hotplug (drm_fbdev_generic.c:?)
> > [ 25.996363][ T1] drm_fbdev_generic_setup (??:?)
> > [ 25.996389][ T1] bochs_pci_probe (bochs.c:?)
> > [ 25.996413][ T1] ? bochs_hw_init (bochs.c:?)
> > [ 25.996429][ T1] ? trace_hardirqs_on (??:?)
> > [ 25.996456][ T1] ? bochs_hw_init (bochs.c:?)
> > [ 25.996477][ T1] local_pci_probe (pci-driver.c:?)
> > [ 25.996507][ T1] pci_call_probe (pci-driver.c:?)
> > [ 25.996520][ T1] ? rcu_read_lock_bh_held (??:?)
> > [ 25.996543][ T1] ? local_pci_probe (pci-driver.c:?)
> > [ 25.996563][ T1] ? __kasan_check_read (??:?)
> > [ 25.996830][ T1] ? pci_match_id (??:?)
> > [ 25.996854][ T1] ? pci_match_device (pci-driver.c:?)
> > [ 25.996882][ T1] pci_device_probe (pci-driver.c:?)
> > [ 25.996904][ T1] really_probe (dd.c:?)
> > [ 25.996933][ T1] __driver_probe_device (dd.c:?)
> > [ 25.996955][ T1] ? __device_attach_driver (dd.c:?)
> > [ 25.996970][ T1] driver_probe_device (dd.c:?)
> > [ 25.996992][ T1] __driver_attach (dd.c:?)
> > [ 25.997014][ T1] ? __device_attach_driver (dd.c:?)
> > [ 25.997030][ T1] bus_for_each_dev (??:?)
> > [ 25.997050][ T1] ? next_device (core.c:?)
> > [ 25.997069][ T1] ? do_raw_spin_unlock (??:?)
> > [ 25.997107][ T1] driver_attach (??:?)
> > [ 25.997127][ T1] bus_add_driver (??:?)
> > [ 25.997158][ T1] driver_register (??:?)
> > [ 25.997182][ T1] __pci_register_driver (??:?)
> > [ 25.997202][ T1] ? etnaviv_init (bochs.c:?)
> > [ 25.997221][ T1] bochs_pci_driver_init (bochs.c:?)
> > [ 25.997240][ T1] do_one_initcall (??:?)
> > [ 25.997260][ T1] ? rcu_lock_acquire (??:?)
> > [ 25.997277][ T1] ? lock_is_held (signal.c:?)
> > [ 25.997293][ T1] ? rcu_read_lock_sched_held (??:?)
> > [ 25.997311][ T1] ? rcu_read_lock_bh_held (??:?)
> > [ 25.997325][ T1] ? ____kasan_kmalloc (common.c:?)
> > [ 25.997348][ T1] ? __kasan_check_read (??:?)
> > [ 25.997376][ T1] do_initcalls (main.c:?)
> > [ 25.997419][ T1] kernel_init_freeable (main.c:?)
> > [ 25.997434][ T1] ? rest_init (main.c:?)
> > [ 25.997461][ T1] kernel_init (main.c:?)
> > [ 25.997481][ T1] ret_from_fork (??:?)
> > [ 25.997537][ T1] </TASK>
> > [ 25.997547][ T1] irq event stamp: 177845
> > [ 25.997555][ T1] hardirqs last enabled at (177851): console_trylock_spinning (printk.c:?)
> > [ 25.997573][ T1] hardirqs last disabled at (177856): console_trylock_spinning (printk.c:?)
> > [ 25.997589][ T1] softirqs last enabled at (176444): __do_softirq (??:?)
> > [ 25.997608][ T1] softirqs last disabled at (176437): __irq_exit_rcu (softirq.c:?)
> > [ 25.997623][ T1] ---[ end trace 0000000000000000 ]---
> > [ 26.013462][ T14] general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN
> > [ 26.013480][ T14] KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
> > [ 26.013490][ T14] CPU: 0 PID: 14 Comm: kworker/0:1 Tainted: G W T 6.2.0-rc6-01191-g180253782038 #1 a8db67375c3ac749313dafaec43f39836e38fae9
> > [ 26.013503][ T14] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-5 04/01/2014
> > [ 26.013509][ T14] Workqueue: events drm_fb_helper_damage_work
> > [ 26.013528][ T14] RIP: 0010:ttm_mem_io_reserve (??:?)
> > [ 26.013544][ T14] Code: f6 31 ff 45 31 c0 c3 55 b8 ff ff 37 00 48 c1 e0 2a 48 89 e5 41 55 49 89 fd 48 8d 7e 20 48 89 fa 41 54 49 89 f4 48 c1 ea 03 53 <80> 3c 02 00 74 05 e8 05 60 e5 fe 49 83 7c 24 20 00 74 07 31 c0 e9
> > All code
> > ========
> > 0: f6 31 divb (%rcx)
> > 2: ff 45 31 incl 0x31(%rbp)
> > 5: c0 c3 55 rol $0x55,%bl
> > 8: b8 ff ff 37 00 mov $0x37ffff,%eax
> > d: 48 c1 e0 2a shl $0x2a,%rax
> > 11: 48 89 e5 mov %rsp,%rbp
> > 14: 41 55 push %r13
> >
> >
> > To reproduce:
> >
> > # build kernel
> > cd linux
> > cp config-6.2.0-rc6-01191-g180253782038 .config
> > make HOSTCC=gcc-11 CC=gcc-11 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage modules
> > make HOSTCC=gcc-11 CC=gcc-11 ARCH=x86_64 INSTALL_MOD_PATH=<mod-install-dir> modules_install
> > cd <mod-install-dir>
> > find lib/ | cpio -o -H newc --quiet | gzip > modules.cgz
> >
> >
> > git clone https://github.com/intel/lkp-tests.git
> > cd lkp-tests
> > bin/lkp qemu -k <bzImage> -m modules.cgz job-script # job-script is attached in this email
> >
> > # if come across any failure that blocks the test,
> > # please remove ~/.lkp and /lkp dir to run from a clean state.
> >
> >
> >
>
