Lockup with kernel 5.5.0-rc5

[Holger Kiehl]

Hello,

on a Broadwell CPU Xeon E3-1285L (with L4-Cache 128MB eDRAM) I got
the following Oops:

[ 7759.828500] general protection fault: 0000 [#1] SMP PTI
[ 7759.828506] CPU: 1 PID: 2114 Comm: Xorg Not tainted 5.5.0-rc5 #1
[ 7759.828508] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./C226M WS, BIOS L2.32 05/16/2019
[ 7759.828515] RIP: 0010:kmem_cache_alloc+0x7a/0x210
[ 7759.828518] Code: 65 48 8b 51 08 65 48 03 0d f3 6a d8 7c 4c 8b 21 4d 85 e4 0f 84 7c 01 00 00 41 8b 5e 20 48 8d 4a 01 4c 89 e0 49 8b 3e 4c 01 e3 <48> 33 1b 49 33 9e 70 01 00 00 65 48 0f c7 0f 0f 94 c0 84 c0 74 bd
[ 7759.828520] RSP: 0018:ffffa72744a2ba28 EFLAGS: 00010206
[ 7759.828522] RAX: 0b1b4d50ef46eaf3 RBX: 0b1b4d50ef46eaf3 RCX: 000000000001b5a9
[ 7759.828524] RDX: 000000000001b5a8 RSI: 0000000000000cc0 RDI: 000000000002ff20
[ 7759.828525] RBP: 0000000000000cc0 R08: 0000000000000000 R09: ffff9be2339e3c80
[ 7759.828527] R10: 000000000000a000 R11: ffff9be3872118e8 R12: 0b1b4d50ef46eaf3
[ 7759.828529] R13: ffffffffc039ddce R14: ffff9be38b823640 R15: ffff9be38b823640
[ 7759.828531] FS:  00007fa28d224f00(0000) GS:ffff9be38ec40000(0000) knlGS:0000000000000000
[ 7759.828533] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7759.828534] CR2: 00007fa28818b000 CR3: 00000007df1d8005 CR4: 00000000003606e0
[ 7759.828536] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 7759.828537] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 7759.828539] Call Trace:
[ 7759.828577]  i915_active_ref+0x5e/0x170 [i915]
[ 7759.828609]  i915_vma_move_to_active+0x24/0x150 [i915]
[ 7759.828636]  i915_gem_do_execbuffer+0xd3f/0x1880 [i915]
[ 7759.828644]  ? unix_stream_read_generic+0x1fe/0x990
[ 7759.828647]  ? xas_load+0x5/0x70
[ 7759.828651]  ? find_get_entry+0xb3/0x170
[ 7759.828657]  ? shmem_getpage_gfp+0xf1/0x8f0
[ 7759.828661]  ? __kmalloc+0x174/0x260
[ 7759.828688]  i915_gem_execbuffer2_ioctl+0xee/0x3b0 [i915]
[ 7759.828718]  ? i915_gem_madvise_ioctl+0x10f/0x2c0 [i915]
[ 7759.828744]  ? i915_gem_execbuffer_ioctl+0x2c0/0x2c0 [i915]
[ 7759.828748]  drm_ioctl_kernel+0xab/0xf0
[ 7759.828753]  drm_ioctl+0x200/0x3a0
[ 7759.828793]  ? i915_gem_execbuffer_ioctl+0x2c0/0x2c0 [i915]
[ 7759.828801]  do_vfs_ioctl+0x447/0x6c0
[ 7759.828807]  ? handle_mm_fault+0xae/0x1e0
[ 7759.828812]  ksys_ioctl+0x5e/0x90
[ 7759.828817]  __x64_sys_ioctl+0x16/0x20
[ 7759.828821]  do_syscall_64+0x55/0x1a0
[ 7759.828826]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 7759.828831] RIP: 0033:0x7fa28d69b34b
[ 7759.828835] Code: 0f 1e fa 48 8b 05 3d 9b 0c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 0d 9b 0c 00 f7 d8 64 89 01 48
[ 7759.828838] RSP: 002b:00007ffc1ae65108 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[ 7759.828842] RAX: ffffffffffffffda RBX: 00007ffc1ae65150 RCX: 00007fa28d69b34b
[ 7759.828845] RDX: 00007ffc1ae65150 RSI: 0000000040406469 RDI: 0000000000000010
[ 7759.828848] RBP: 0000000040406469 R08: 00005557e3a829a0 R09: 0000000000000000
[ 7759.828850] R10: 0000000000000000 R11: 0000000000000246 R12: 00005557e3a40100
[ 7759.828853] R13: 0000000000000010 R14: ffffffffffffffff R15: 00007fa28cb34a68
[ 7759.828858] Modules linked in: xt_CHECKSUM xt_MASQUERADE nf_nat_tftp nf_conntrack_tftp tun bridge stp llc nf_conntrack_netbios_ns nf_conntrack_broadcast xt_CT ip6t_REJECT nf_reject_ipv6 ip6t_rpfilter xt_conntrack ebtable_nat ebtable_broute ip6table_nat ip6table_mangle ip6table_raw ip6table_security iptable_nat nf_nat iptable_mangle iptable_raw iptable_security nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c ip_set nfnetlink ebtable_filter ebtables x86_pkg_temp_thermal ip6table_filter kvm_intel ip6_tables kvm irqbypass bpfilter iTCO_wdt iTCO_vendor_support snd_hda_codec_realtek crct10dif_pclmul snd_hda_codec_generic snd_hda_codec_hdmi crc32_pclmul snd_hda_intel snd_intel_dspcfg snd_hda_codec snd_hwdep snd_hda_core nct6775 hwmon_vid ghash_clmulni_intel i2c_i801 snd_seq jc42 lpc_ich bfq mfd_core coretemp snd_seq_device snd_pcm snd_timer snd mei_me mei soundcore acpi_pad sunrpc vfat fat sch_fq_codel i915 crc32c_intel igb dca video fuse ecryptfs
[ 7759.828934] ---[ end trace f5069fc029a440f1 ]---
[ 7759.929159] RIP: 0010:kmem_cache_alloc+0x7a/0x210
[ 7759.929162] Code: 65 48 8b 51 08 65 48 03 0d f3 6a d8 7c 4c 8b 21 4d 85 e4 0f 84 7c 01 00 00 41 8b 5e 20 48 8d 4a 01 4c 89 e0 49 8b 3e 4c 01 e3 <48> 33 1b 49 33 9e 70 01 00 00 65 48 0f c7 0f 0f 94 c0 84 c0 74 bd
[ 7759.929163] RSP: 0018:ffffa72744a2ba28 EFLAGS: 00010206
[ 7759.929165] RAX: 0b1b4d50ef46eaf3 RBX: 0b1b4d50ef46eaf3 RCX: 000000000001b5a9
[ 7759.929166] RDX: 000000000001b5a8 RSI: 0000000000000cc0 RDI: 000000000002ff20
[ 7759.929167] RBP: 0000000000000cc0 R08: 0000000000000000 R09: ffff9be2339e3c80
[ 7759.929168] R10: 000000000000a000 R11: ffff9be3872118e8 R12: 0b1b4d50ef46eaf3
[ 7759.929169] R13: ffffffffc039ddce R14: ffff9be38b823640 R15: ffff9be38b823640
[ 7759.929171] FS:  00007fa28d224f00(0000) GS:ffff9be38ec40000(0000) knlGS:0000000000000000
[ 7759.929172] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7759.929173] CR2: 00007fa28818b000 CR3: 00000007df1d8005 CR4: 00000000003606e0
[ 7759.929174] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 7759.929175] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

It cannot be reproduced, but it has happened now the second time with
a 5.5.0-rc kernel. Before this system was stable if one does not enable
C6 power saving. It is limited to C3.

Regards,
Holger