Hi Marek,

On Tue, Nov 04, 2025 at 09:44:38AM +0100, Marek Szyprowski wrote:

On 03.11.2025 16:24, Mark Brown wrote:

quoted

On Tue, Oct 14, 2025 at 08:49:09AM +0200, Thomas Weißschuh wrote:

quoted

An upcoming change will allocate the datapages dynamically instead of as
part of the kernel image. Such pages can only be mapped through
'struct page' and not through PFNs.

I'm seeing some boot failures on some arm64 platforms in -next which are
bisecting to this patch in -next.  Unfortunately the diagnostics aren't
super useful, we seem to just stop making progress in userspace with no
obvious output.  One sample log from the FVP is:

(...)

Then I've tested it on ARM64bit (RaspberrryPi3b+ board) and got the 
following panic on 6a011a228293 ("vdso/datastore: Map pages through 
struct page") commit:

VFS: Mounted root (ext4 filesystem) on device 179:3. Trying to move old 
root to /initrd ... okay devtmpfs: mounted Freeing unused kernel memory: 
12672K Run /sbin/init as init process Unable to handle kernel paging 
request at virtual address ffffffffc20b5d48 Mem abort info: ESR = 
0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, 
FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data 
abort info: ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 CM = 0, WnR = 
0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 
swapper pgtable: 4k pages, 48-bit VAs, pgdp=000000000230b000 
[ffffffffc20b5d48] pgd=0000000000000000, p4d=0000000003618403, 
pud=0000000003619403, pmd=0000000000000000 Internal error: Oops: 
0000000096000006 [#1] SMP Modules linked in: CPU: 2 UID: 0 PID: 1 Comm: 
init Tainted: G W 6.18.0-rc1+ #16136 PREEMPT Tainted: [W]=WARN Hardware 
name: Raspberry Pi 3 Model B (DT) pstate: 80000005 (Nzcv daif -PAN -UAO 
-TCO -DIT -SSBS BTYPE=--) pc : vvar_fault+0x7c/0x17c lr : 
vvar_fault+0x24/0x17c ... Call trace: vvar_fault+0x7c/0x17c (P) 
special_mapping_fault+0x24/0xd0 __do_fault+0x3c/0x238 
__handle_mm_fault+0xaa0/0x19e0 handle_mm_fault+0xcc/0x384 
do_page_fault+0x1a0/0x720 do_translation_fault+0x60/0x6c 
do_mem_abort+0x44/0x94 el0_da+0x54/0x230 el0t_64_sync_handler+0xd0/0xe4 
el0t_64_sync+0x198/0x19c Code: f2d83fe0 8b010063 d34cfc63 8b031803 
(f9400461) ---[ end trace 0000000000000000 ]--- Kernel panic - not 
syncing: Attempted to kill init! exitcode=0x0000000b SMP: stopping 
secondary CPUs Kernel Offset: disabled CPU features: 
0x000000,00180000,40004000,0400421b Memory Limit: none ---[ end Kernel 
panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]---

Reverting "clocksource: Remove ARCH_CLOCKSOURCE_DATA", "vdso/datastore: 
Allocate data pages dynamically" and "vdso/datastore: Map pages through 
struct page" on top of linux-next fixes booting on all tested boards.

Thanks for the report. I have a Raspberry Pi 3 Model B V1.2 here and will try
to reproduce the issue with it.
Can you send me your kernel configuration?
Which line is vvar_fault+0x7c/0x17c?


Thomas