Re: Linux 6.15-rc1 regression, folio/ubifs Oops

Francesco Dolcini
2025-04-22T17:54:15Z

+ Herbert, Zhihao

Hello all,

On Tue, Apr 08, 2025 at 10:20:18AM +0200, Francesco Dolcini wrote:
> I do have the following regression on single core system using UBIFS,
> dual core seems not affected, any idea?
>
> [ 1.003798] 8<--- cut here ---
> [ 1.003843] Unable to handle kernel paging request at virtual address d21af3b8 when read
> [ 1.003876] [d21af3b8] *pgd=00000000
> [ 1.003914] Internal error: Oops: 5 [#1] SMP ARM
> [ 1.023282] Modules linked in:
> [ 1.026371] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.15.0-rc1-0.0.0-devel #1 PREEMPT
> [ 1.035110] Hardware name: Freescale i.MX7 Dual (Device Tree)
> [ 1.040881] PC is at scomp_acomp_comp_decomp+0x138/0x390
> [ 1.046243] LR is at scomp_acomp_decompress+0x10/0x48
> [ 1.051336] pc : [<c050aa90>] lr : [<c050b07c>] psr: 20000013
> [ 1.057634] sp : d0825a98 ip : 00000024 fp : c221d780
> [ 1.062886] r10: 00000576 r9 : d0825af0 r8 : c204e030
> [ 1.068137] r7 : cfdaf3b8 r6 : cfdaf3b8 r5 : c27b2540 r4 : cfd5b1e8
> [ 1.074694] r3 : 02400000 r2 : 00001000 r1 : d0b01000 r0 : 00000000
> [ 1.081251] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
> [ 1.088419] Control: 10c5387d Table: 8000406a DAC: 00000051
> [ 1.094189] Register r0 information: NULL pointer
> [ 1.098929] Register r1 information: 16-page vmalloc region starting at 0xd0b01000 allocated at crypto_scomp_init_tfm+0x8c/0x180
> [ 1.110556] Register r2 information: non-paged memory
> [ 1.115641] Register r3 information: non-paged memory
> [ 1.120726] Register r4 information: non-slab/vmalloc memory
> [ 1.126421] Register r5 information: slab kmalloc-192 start c27b2540 pointer offset 0 size 192
> [ 1.135112] Register r6 information: non-slab/vmalloc memory
> [ 1.140806] Register r7 information: non-slab/vmalloc memory
> [ 1.146500] Register r8 information: slab kmalloc-8k start c204e000 pointer offset 48 size 8192
> [ 1.155280] Register r9 information: 2-page vmalloc region starting at 0xd0824000 allocated at kernel_clone+0xa4/0x33c
> [ 1.166043] Register r10 information: non-paged memory
> [ 1.171219] Register r11 information: slab kmalloc-64 start c221d780 pointer offset 0 size 64
> [ 1.179827] Register r12 information: non-paged memory
> [ 1.185003] Process swapper/0 (pid: 1, stack limit = 0x(ptrval))
> [ 1.191043] Stack: (0xd0825a98 to 0xd0826000)
> [ 1.195431] 5a80: 00000004 c07edfcc
> [ 1.203650] 5aa0: 00000000 00000000 00001000 c7d16f8f 04070598 c27b2540 c27b2540 c28b0000
> [ 1.211870] 5ac0: d0825c94 c0dc7064 d0825af0 c204e030 d0825c94 c050b07c c27b2540 00000576
> [ 1.220089] 5ae0: c28b0000 c04d40b8 00000000 c07ebbd0 00000000 00000000 d0825af8 d0825af8
> [ 1.228308] 5b00: 00000000 c7d16f8f c28b0000 c117b6d0 00000000 c204e030 cfdaf3b8 c43f7080
> [ 1.236527] 5b20: d0825b40 c04d47e0 d0825c94 c0dc7064 00000576 c2213cc0 0000f598 000005a6
> [ 1.244745] 5b40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> [ 1.252963] 5b60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> [ 1.261182] 5b80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> [ 1.269400] 5ba0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> [ 1.277618] 5bc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> [ 1.285837] 5be0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> [ 1.294056] 5c00: c28b0000 c04c5e54 00000001 00000000 00000001 c289eb00 000009e4 20000000
> [ 1.302275] 5c20: 00000000 000002b0 0000f598 000005a6 c204e000 c7d16f8f cfd5fec0 00000000
> [ 1.310494] 5c40: 00000000 cfdaf3b8 00000000 00000000 c43f7080 c204e000 00001000 c04b58b4
> [ 1.318713] 5c60: 00000000 d0825c94 00000001 c7d16f8f d0825d50 c7d16f8f 00040cc0 00000016
> [ 1.326932] 5c80: c28b0000 00000000 00015600 c2068000 cfdaf3b8 00001000 000009e4 20000000
> [ 1.335151] 5ca0: 00000001 c7d16f8f 0eced000 cfdaf3b8 c28b0000 00000000 c27fc0c0 c43f7080
> [ 1.343370] 5cc0: 00000000 c43f7180 c27fc0c0 c04b60e4 00000000 ffffffff 00000000 c02a0430
> [ 1.351590] 5ce0: 00000cc0 00000001 ffffc005 00000001 d0825d50 00000000 c2068000 c7d16f8f
> [ 1.359809] 5d00: c43f7184 cfdaf3b8 00000000 c2068000 c27fc0c0 c43f7180 c2068000 c43f7180
> [ 1.368028] 5d20: c27fc0c0 c029e91c 00000000 c02ae4d8 00000000 00000000 c2068000 c43f7180
> [ 1.376247] 5d40: c27fc0c0 c7d16f8f d0825d50 d0825ef0 00000000 d0825e14 cfdaf3b8 c43f7180
> [ 1.384466] 5d60: c2068000 c43f7180 c27fc0c0 c02a0c5c 0eced000 00000000 00000001 00000000
> [ 1.392685] 5d80: c43f7190 00000000 00000100 c2068000 00000001 c2014800 c27fc0c0 c43f7180
> [ 1.400904] 5da0: c27fc120 00000000 00000000 00000000 00000000 00000000 000001ff c7d16f8f
> [ 1.409123] 5dc0: c2952fb8 00000000 d0825ed8 c43f7080 00000000 00000000 ffffffff ffffffff
> [ 1.417342] 5de0: d0825ef0 c02a10f4 00000000 d0825ed8 c289f000 beffffd4 00050003 c43f7080
> [ 1.425561] 5e00: cfdaf3dc c02d4c24 c43f7180 c27fc0c0 cfde4694 00000000 00000000 00000000
> [ 1.433779] 5e20: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> [ 1.441997] 5e40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> [ 1.450215] 5e60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> [ 1.458433] 5e80: 00000000 00000000 00000000 00000000 00000000 c7d16f8f 00000000 00000000
> [ 1.466653] 5ea0: c27fc0c0 d0825f48 00000100 00000000 00000000 00000006 c2864a58 c0329db8
> [ 1.474871] 5ec0: 00000100 00000001 00000000 00050001 c2864a58 00000100 00000003 00000000
> [ 1.483090] 5ee0: d0825ed0 00000100 00000001 00000000 c27fc0c0 00000000 00000000 00000000
> [ 1.491308] 5f00: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 c7d16f8f
> [ 1.499527] 5f20: 00000000 c2864a00 00000000 00000001 c2068000 c11ed360 00000000 c0332988
> [ 1.507745] 5f40: 00000000 00000001 00000000 00000000 c2068000 c7d16f8f 00000000 c2864a00
> [ 1.515964] 5f60: c20e0000 c1108094 00000000 00000000 00000000 00000000 00000000 c0333de0
> [ 1.524183] 5f80: c11bd000 c0d8c568 00000000 00000000 00000000 c0101364 c11bd000 c0b40a68
> [ 1.532401] 5fa0: 00000000 c0b40b4c 00000000 c010014c 00000000 00000000 00000000 00000000
> [ 1.540620] 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> [ 1.548838] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
> [ 1.557050] Call trace:
> [ 1.557069] scomp_acomp_comp_decomp from scomp_acomp_decompress+0x10/0x48
> [ 1.566549] scomp_acomp_decompress from ubifs_decompress_req+0xa8/0x148
> [ 1.573313] ubifs_decompress_req from ubifs_decompress_folio+0xdc/0x20c
> [ 1.580065] ubifs_decompress_folio from do_readpage+0x1e0/0x4b0
> [ 1.586116] do_readpage from ubifs_read_folio+0x4c/0x4d8
> [ 1.591557] ubifs_read_folio from filemap_read_folio+0x30/0x1fc
> [ 1.597612] filemap_read_folio from filemap_get_pages+0x534/0x8ac
> [ 1.603841] filemap_get_pages from filemap_read+0x120/0x504
> [ 1.609546] filemap_read from __kernel_read+0x164/0x2f4
> [ 1.614907] __kernel_read from bprm_execve+0x194/0x3f4
> [ 1.620180] bprm_execve from kernel_execve+0x114/0x19c
> [ 1.625450] kernel_execve from try_to_run_init_process+0xc/0x38
> [ 1.631505] try_to_run_init_process from kernel_init+0xe4/0x134
> [ 1.637565] kernel_init from ret_from_fork+0x14/0x28
> [ 1.642663] Exception stack(0xd0825fb0 to 0xd0825ff8)
> [ 1.647747] 5fa0: 00000000 00000000 00000000 00000000
> [ 1.655966] 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> [ 1.664183] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> [ 1.670835] Code: e1a03623 e0833622 e026609c e003039c (e7963003)
> [ 1.676964] ---[ end trace 0000000000000000 ]---
> [ 1.681608] note: swapper/0[1] exited with irqs disabled
> [ 1.681787] random: crng init done
> [ 1.691090] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
> [ 1.698805] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]---
>

The issue is still present on current master, I did bisect it, the
regression is from commit 7e0969bae493 ("ubifs: Pass folios to acomp"),
reverting it on top of current master solves the issue.

How should we proceed?

Unless someone is able to look into that I gonna send a revert patch,
the regression is severe, the machine is not booting anymore.

Francesco