Hi
I report this crash on ARM64 on the kernel 4.17.11. The reason is that the
function move_freepages_block accesses contiguous runs of
pageblock_nr_pages. The ARM64 firmware sets holes of reserved memory there
and when move_freepages_block stumbles over this hole, it accesses
uninitialized page structures and crashes.
00000000-03ffffff : System RAM
00080000-007bffff : Kernel code
00820000-00aa3fff : Kernel data
04200000-bf80ffff : System RAM
bf810000-bfbeffff : reserved
bfbf0000-bfc8ffff : System RAM
bfc90000-bffdffff : reserved
bffe0000-bfffffff : System RAM
c0000000-dfffffff : MEM
c0000000-c00fffff : PCI Bus 0000:01
c0000000-c0003fff : 0000:01:00.0
c0000000-c0003fff : nvme
The bug was already reported here for x86:
https://bugzilla.redhat.com/show_bug.cgi?id=1598462
For x86, it was fixed in the kernel 4.17.7 - but I observed it in the
kernel 4.17.11 on ARM64. I also observed it on 4.18-rc kernels running in
KVM virtual machine on ARM when I compiled the guest kernel with 64kB page
size.
Unable to handle kernel paging request at virtual address fffffffffffffffe
Mem abort info:
ESR = 0x96000005
Exception class = DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000005
CM = 0, WnR = 0
swapper pgtable: 4k pages, 39-bit VAs, pgdp = 00000000791c2068
[fffffffffffffffe] pgd=0000000000000000, pud=0000000000000000
Internal error: Oops: 96000005 [#1] PREEMPT SMP
Modules linked in: ftdi_sio usbserial fuse vhost_net vhost tun bridge stp llc autofs4 udlfb syscopyarea sysfillrect sysimgblt fb_sys_fops fb font binfmt_misc ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables ipt_MASQUERADE nf_nat_masquerade_ipv4 xt_nat iptable_nat nf_nat_ipv4 iptable_mangle xt_TCPMSS nf_conntrack_ipv4 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 xt_tcpudp xt_conntrack xt_multiport iptable_filter ip_tables x_tables pppoe pppox af_packet ppp_generic slhc nls_utf8 nls_cp852 vfat fat hid_generic usbhid hid snd_usb_audio snd_hwdep snd_usbmidi_lib snd_rawmidi snd_pcm snd_timer snd soundcore nf_nat_ftp nf_conntrack_ftp nf_nat nf_conntrack sd_mod ipv6 aes_ce_blk crypto_simd cryptd aes_ce_cipher crc32_ce ghash_ce gf128mul aes_arm64 sha2_ce sha256_arm64
sha1_ce sha1_generic efivars xhci_plat_hcd xhci_hcd ahci_platform libahci_platform libahci libata usbcore usb_common mvpp2 unix
CPU: 3 PID: 14823 Comm: updatedb.mlocat Not tainted 4.17.11 #16
Hardware name: Marvell Armada 8040 MacchiatoBin/Armada 8040 MacchiatoBin, BIOS EDK II Jul 30 2018
pstate: 00000085 (nzcv daIf -PAN -UAO)
pc : move_freepages_block+0xb4/0x160
lr : steal_suitable_fallback+0xe4/0x188
sp : ffffffc0add9f570
x29: ffffffc0add9f570 x28: 0000000000000000
x27: ffffffffffffff60 x26: ffffff800886ef58
x25: 0000000000000008 x24: 0000000000000003
x23: 0000000000000020 x22: 0000000000000000
x21: 0000000000000003 x20: ffffff800886ed80
x19: 0000000000000002 x18: ffffffbf02fefe00
x17: 0000007fa0916380 x16: ffffff80081dc528
x15: 0000000000000001 x14: 0000000000000020
x13: 0000000000000068 x12: 0000000000000080
x11: ffffffbf02fe8020 x10: ffffff800886ef38
x9 : 0000000000000000 x8 : 0000000000000000
x7 : 0000000000100000 x6 : ffffffffffffffff
x5 : fffffffffffffffe x4 : ffffffbf02feffc0
x3 : ffffffc0add9f5ac x2 : 00000000000000a0
x1 : ffffffbf02fe8000 x0 : ffffff800886ed80
Process updatedb.mlocat (pid: 14823, stack limit = 0x000000005d2941e3)
Call trace:
move_freepages_block+0xb4/0x160
get_page_from_freelist+0xad8/0xea8
__alloc_pages_nodemask+0xac/0x970
new_slab+0xc0/0x348
___slab_alloc.constprop.32+0x2cc/0x350
__slab_alloc.isra.26.constprop.31+0x24/0x38
kmem_cache_alloc+0x168/0x198
spadfs_alloc_inode+0x2c/0x88
alloc_inode+0x20/0xa0
iget5_locked+0xf8/0x1c0
spadfs_iget+0x44/0x4c8
spadfs_lookup+0x70/0x108
__lookup_slow+0x78/0x140
lookup_slow+0x3c/0x60
walk_component+0x1e4/0x2e0
path_lookupat.isra.11+0x64/0x1e8
filename_lookup.part.20+0x6c/0xe8
user_path_at_empty+0x4c/0x60
vfs_statx+0x78/0xd8
sys_newfstatat+0x24/0x48
el0_svc_naked+0x30/0x34
Code: f9401026 d10004c5 f24000df 9a8110a5 (f94000a5)
---[ end trace def2ceafdfecd702 ]---
note: updatedb.mlocat[14823] exited with preempt_count 1
