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This change has been made by an automated script, maintained by the Ubuntu Kernel Team. ** Changed in: linux (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1955717 Title: BUG: unsupported FP instruction in kernel mode FPEXC == 0x40000700 at the end of a btrfs balance to RAID1 Status in linux package in Ubuntu: Incomplete Bug description: Hello there, on my Raspberry Pi 4 I needed to convert a volume to RAID1, so I added a disk and launched btrfs balance: #> sudo btrfs balance start -dconvert=raid1 -mconvert=raid1 /mnt/mountpoint The volume was 5 Tb worth of data, and after a couple of days the process looked terminated correctly, in "sudo btrfs filesystem show" everything looked ok: Label: 'mountpoint' uuid: 15d2c29b-dc20-48a9-910d-e1af8948ed08 Total devices 2 FS bytes used 4.38TiB devid 1 size 5.45TiB used 5.16TiB path /dev/mapper/dev-sdb1 devid 2 size 8.65TiB used 5.16TiB path /dev/mapper/dev-sda3 The total size is less than the single devices size because during the process I managed to free up 1 Tb of data. Anyway, I looked at the screen containing the balance command and it actually terminated with a segfault, and dmesg was reporting this: [ven dic 24 13:04:06 2021] BTRFS info (device dm-5): relocating block group 2177892352 flags data [ven dic 24 13:04:43 2021] BTRFS info (device dm-5): found 462 extents, stage: move data extents [ven dic 24 13:04:44 2021] BTRFS info (device dm-5): found 462 extents, stage: update data pointers [ven dic 24 13:04:44 2021] BTRFS info (device dm-5): relocating block group 1104150528 flags data [ven dic 24 13:05:22 2021] BTRFS info (device dm-5): found 2625 extents, stage: move data extents [ven dic 24 13:05:23 2021] BTRFS info (device dm-5): found 2625 extents, stage: update data pointers [ven dic 24 13:05:24 2021] BTRFS info (device dm-5): relocating block group 30408704 flags metadata|dup [ven dic 24 13:05:56 2021] BTRFS info (device dm-5): found 2412 extents, stage: move data extents [ven dic 24 13:06:00 2021] BTRFS info (device dm-5): relocating block group 22020096 flags system|dup [ven dic 24 13:06:01 2021] BTRFS info (device dm-5): balance: ended with status: 0 [ven dic 24 13:06:01 2021] BUG: unsupported FP instruction in kernel mode [ven dic 24 13:06:01 2021] FPEXC == 0x40000700 [ven dic 24 13:06:01 2021] Internal error: Oops - undefined instruction: 0 [#1] SMP ARM [ven dic 24 13:06:01 2021] Modules linked in: rpcsec_gss_krb5 veth cdc_acm aes_arm_bs crypto_simd cryptd dm_crypt dm_mod fuse xt_nat xt_tcpudp xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink xt_addrtype iptable_filter iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter bridge stp llc overlay sg sch_fq_codel nfsd ip_tables x_tables ipv6 btrfs blake2b_generic zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor xor_neon raid6_pq raid1 raid0 linear md_mod hid_logitech_hidpp joydev hid_logitech_dj brcmfmac brcmutil vc4 sha256_generic v3d cec gpu_sched drm_kms_helper cfg80211 bcm2835_codec(C) raspberrypi_hwmon rfkill bcm2835_v4l2(C) bcm2835_isp(C) bcm2835_mmal_vchiq(C) v4l2_mem2mem videobuf2_vmalloc videobuf2_dma_contig videobuf2_memops drm videobuf2_v4l2 videobuf2_common vc_sm_cma(C) videodev snd_bcm2835(C) mc drm_panel_orientation_quirks snd_soc_core rpivid_mem snd_compress snd_pcm_dmaengine snd_pcm snd_timer snd syscopyarea sysfillrect [ven dic 24 13:06:01 2021] sysimgblt fb_sys_fops backlight uio_pdrv_genirq nvmem_rmem uio [last unloaded: cdc_acm] [ven dic 24 13:06:01 2021] CPU: 3 PID: 9141 Comm: btrfs Tainted: G C 5.10.63-v7l+ #1459 [ven dic 24 13:06:01 2021] Hardware name: BCM2711 [ven dic 24 13:06:01 2021] PC is at vfp_reload_hw+0x30/0x44 [ven dic 24 13:06:01 2021] LR is at __und_usr_fault_32+0x0/0x8 [ven dic 24 13:06:01 2021] pc : [<c0203834>] lr : [<c0200fc0>] psr: a0070013 [ven dic 24 13:06:01 2021] sp : ca0adfb0 ip : ca0adf30 fp : 00000003 [ven dic 24 13:06:01 2021] r10: ca0ac1f8 r9 : c0201024 r8 : c1205048 [ven dic 24 13:06:01 2021] r7 : 00000001 r6 : 00000000 r5 : c0288068 r4 : c88f60f8 [ven dic 24 13:06:01 2021] r3 : c135607c r2 : b6cfeb8c r1 : ae24b2ce r0 : f421070d [ven dic 24 13:06:01 2021] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ven dic 24 13:06:01 2021] Control: 30c5383d Table: 0335dd80 DAC: 55555555 [ven dic 24 13:06:01 2021] Process btrfs (pid: 9141, stack limit = 0x7d756e7e) [ven dic 24 13:06:01 2021] Stack: (0xca0adfb0 to 0xca0ae000) [ven dic 24 13:06:01 2021] dfa0: 00ad81d2 00491e87 00000008 0000002c [ven dic 24 13:06:01 2021] dfc0: 00000008 b6d95d28 00491e8f 00000000 00000000 00491e87 b6cef66d b6d95e4c [ven dic 24 13:06:01 2021] dfe0: 00ad81d2 be903718 b6cfa6d5 b6cfeb8c 80070010 ffffffff 00000000 00000000 [ven dic 24 13:06:01 2021] Backtrace: invalid frame pointer 0x00000003 [ven dic 24 13:06:01 2021] Code: 128aa080 e89a0162 e3110102 0a000003 (eee96a10) [ven dic 24 13:06:01 2021] ---[ end trace b013d23166ad7965 ]--- I'm running Ubuntu 20.04 32 bit with kernel 5.10.63-v7l+ and btrfs- progs/btrfs-tools at these versions: ii btrfs-progs 5.4.1-2 armhf Checksumming Copy on Write Filesystem utilities ii btrfs-tools 4.15.1-1build1 armhf transitional dummy package btrfsck terminated correctly without errors, so I think everything is "normal" after all. I'll just leave this bug here for posterity (or I will update the thread if something goes horribly wrong in the immediate future). To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1955717/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp