[PATCH 22/22] drm/amdgpu: fix reservation obj shared count bug

[Liu, Monk]

Please check again

Every time you call amdgpu_bo_fence should first call " reservation_object_reserve_shared", and this patch
Fixed a bug by following this rule

The thing is when shared comes to 4 (assume max is 4) before you call amdgpu_bo_fence, you will hit BUG() at reservation.c's reservation_object_add_shared_fence()
This is a clear fix !



-----Original Message-----
From: Christian König [mailto:ckoenig.leichtzumerken at gmail.com] 
Sent: 2018年2月26日 17:48
To: Liu, Monk <Monk.Liu at amd.com>; amd-gfx at lists.freedesktop.org
Subject: Re: [PATCH 22/22] drm/amdgpu: fix reservation obj shared count bug

That fix is incorrect.

amdgpu_vm_get_pd_bo() should already reserves a shared slot for the fence:
>         entry->tv.shared = true;

So you must run into this issue because of something else.

Regards,
Christian.

Am 26.02.2018 um 06:35 schrieb Monk Liu:
> should call reservation_object_reserve_shared before 
> amdgpu_bo_fence(), otherwise there are odds kernel hit BUG in 
> reversation.c
>
> bug:
> [12622.076435] ------------[ cut here ]------------ [12622.076438] 
> kernel BUG at drivers/dma-buf/reservation.c:233!
> [12622.078046] invalid opcode: 0000 [#1] SMP KASAN [12622.078345] 
> Modules linked in: amdgpu(E) chash(E) gpu_sched(E) ttm(E) drm_kms_helper(E) drm(E) i2c_algo_bit(E) fb_sys_fops(E) syscopyarea(E) sysfillrect(E) sysimgblt(E) amdkfd(E) amd_iommu_v2(E) snd_hda_codec_generic(E) snd_hda_intel(E) snd_hda_codec(E) snd_hda_core(E) snd_hwdep(E) snd_pcm(E) crct10dif_pclmul(E) crc32_pclmul(E) ghash_clmulni_intel(E) pcbc(E) snd_seq_midi(E) snd_seq_midi_event(E) snd_rawmidi(E) snd_seq(E) aesni_intel(E) snd_seq_device(E) aes_x86_64(E) crypto_simd(E) glue_helper(E) cryptd(E) snd_timer(E) serio_raw(E) snd(E) soundcore(E) i2c_piix4(E) mac_hid(E) binfmt_misc(E) nfsd(E) auth_rpcgss(E) nfs_acl(E) lockd(E) grace(E) sunrpc(E) parport_pc(E) ppdev(E) lp(E) parport(E) autofs4(E) 8139too(E) psmouse(E) floppy(E) 8139cp(E) mii(E) pata_acpi(E)
> [12622.082664] CPU: 2 PID: 6075 Comm: ShaderImageLoad Tainted: G            E   4.13.0-feb15-2018-guest-12 #8
> [12622.083278] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), 
> BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [12622.083880] task: 
> ffff8801314f8000 task.stack: ffff8801e6df0000 [12622.084267] RIP: 
> 0010:reservation_object_add_shared_fence+0x2bc/0x2c0
> [12622.084680] RSP: 0018:ffff8801e6df7ae8 EFLAGS: 00010246 
> [12622.085016] RAX: 0000000000000004 RBX: ffff8801f2542a80 RCX: 
> ffff8801f2542b58 [12622.085471] RDX: ffff880044791428 RSI: 
> ffff8801e2657d20 RDI: ffff880044791428 [12622.085995] RBP: 
> ffff8801e6df7b28 R08: 0000000000000000 R09: 0000000000000000 
> [12622.086451] R10: 000000009fe2fe07 R11: 0000000000000002 R12: 
> ffff880044791200 [12622.086905] R13: ffff8801e1da6850 R14: 
> 0000000000000000 R15: ffff8801e9303000 [12622.087359] FS:  
> 00007f70109ff700(0000) GS:ffff8801f7500000(0000) 
> knlGS:0000000000000000 [12622.087874] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [12622.088242] CR2: 00007f6fe1a49000 CR3: 00000001e8377000 CR4: 00000000001406e0 [12622.088698] Call Trace:
> [12622.088934]  amdgpu_bo_fence+0x25/0x30 [amdgpu] [12622.089271]  
> amdgpu_vm_update_directories+0x3d7/0x450 [amdgpu] [12622.089721]  ? 
> amdgpu_vm_free_mapping.isra.20+0x30/0x30 [amdgpu] [12622.090184]  
> amdgpu_gem_va_ioctl+0x409/0x4f0 [amdgpu] [12622.090569]  ? 
> amdgpu_gem_metadata_ioctl+0x1b0/0x1b0 [amdgpu] [12622.090959]  
> drm_ioctl_kernel+0x6a/0xb0 [drm] [12622.091247]  ? 
> kasan_check_write+0x14/0x20 [12622.091517]  drm_ioctl+0x2ea/0x3b0 
> [drm] [12622.091805]  ? amdgpu_gem_metadata_ioctl+0x1b0/0x1b0 [amdgpu] 
> [12622.092212]  amdgpu_drm_ioctl+0x4b/0x80 [amdgpu] [12622.092519]  
> do_vfs_ioctl+0x96/0x5b0 [12622.092754]  ? 
> kvm_sched_clock_read+0x1e/0x30 [12622.093036]  ? 
> kvm_sched_clock_read+0x1e/0x30 [12622.093322]  ? sched_clock+0x9/0x10 
> [12622.093550]  SyS_ioctl+0x79/0x90 [12622.093812]  ? 
> vtime_user_exit+0x29/0x70 [12622.094108]  do_syscall_64+0x6e/0x160 
> [12622.094350]  entry_SYSCALL64_slow_path+0x25/0x25
> [12622.094651] RIP: 0033:0x7f7012ebff07 [12622.094884] RSP: 
> 002b:00007f70109fdae8 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 
> [12622.095369] RAX: ffffffffffffffda RBX: 00007f6fe100fe30 RCX: 
> 00007f7012ebff07 [12622.095827] RDX: 00007f70109fdbb0 RSI: 
> 00000000c0286448 RDI: 0000000000000004 [12622.096283] RBP: 
> 00007f70109fdb20 R08: 0000000332000000 R09: 000000000000000e 
> [12622.096739] R10: 0000000002e2e628 R11: 0000000000000206 R12: 
> 0000000002ebb8f0 [12622.097195] R13: 00007f6fe100fe30 R14: 
> 0000000002fe2bf0 R15: 0000000000000000 [12622.097676] Code: 2b e6 ff 
> ff 41 8b 4f 10 48 8b 75 c8 48 8b 55 d0 e9 06 ff ff ff 49 8d 44 cf 10 
> 45 31 ed 48 89 70 08 41 83 47 10 01 e9 12 ff ff ff <0f> 0b 90 90 0f 1f 
> 44 00 00 55 31 c0 48 81 7f 08 00 df a9 ac 48 [12622.098919] RIP: 
> reservation_object_add_shared_fence+0x2bc/0x2c0 RSP: ffff8801e6df7ae8 
> [12622.099527] ---[ end trace 8235addd8e22e444 ]---
>
> Change-Id: I1de84f60c75a0d78b0cad244b8e2bff02aced9fa
> Signed-off-by: Monk Liu <Monk.Liu at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c 
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 0b237e0..e6f159f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -989,6 +989,11 @@ int amdgpu_vm_update_directories(struct amdgpu_device *adev,
>   		amdgpu_ring_pad_ib(ring, params.ib);
>   		amdgpu_sync_resv(adev, &job->sync, root->tbo.resv,
>   				 AMDGPU_FENCE_OWNER_VM, false);
> +
> +		r = reservation_object_reserve_shared(root->tbo.resv);
> +		if (r)
> +			goto error;
> +
>   		WARN_ON(params.ib->length_dw > ndw);
>   		r = amdgpu_job_submit(job, ring, &vm->entity,
>   				      AMDGPU_FENCE_OWNER_VM, &fence);