Re: selftests: arm64: fp-stress: Unable to handle kernel paging request at virtual address

[Naresh Kamboju]

On Tue, 7 Nov 2023 at 19:51, Mark Brown <broonie@xxxxxxxxxx> wrote:
>
> On Tue, Nov 07, 2023 at 06:43:25PM +0530, Naresh Kamboju wrote:
>
> > # # SVE-VL-64-0: Expected
> > [3904000039044000390480003904c0003904000139044001390480013904c0013904000239044002390480023904c0023904000339044003390480033904c003]
> > <>
>
> You've elided *lots* of error reports from the actual test which suggest
> that there is substantial memory corruption, it looks like tearing part
> way through loading or saving the values - the start of the vectors
> looks fine but at some point they get what looks like a related process'
> data, eg:
>
> # # SVE-VL-64-0:        Expected [3904000039044000390480003904c0003904000139044001390480013904c0013904000239044002390480023904c0023904000339044003390480033904c003]
> # # SVE-VL-64-0:        Got      [3904000039044000390480003904c000390480003904c00039040001390440013904000139044001390480013904c001390480013904c0013904000239044002]
>
> This only appears to affect SVE and SME, I didn't spot any FPSIMD
> corruption but then that is the smallest case (and I didn't notice any
> VL 16 cases either).  It looks like the corruption is on the first thing
> we check each time (either register 0 or the highest ZA.H vector for
> ZA), all the values do look lke they were plausibly generated by
> fp-stress test programs.
>
> Then we get what looks like memory corruption:
>
> > # # SVE-VL-256-<1>[   88.160313] Unable to handle kernel paging
> > request at virtual address 00550f0344550f02
>
> > <4>[   88.195706] Call trace:
> > <4>[ 88.196098] percpu_ref_get_many
> > (include/linux/percpu-refcount.h:174 (discriminator 2)
> > include/linux/percpu-refcount.h:204 (discriminator 2))
> > <4>[ 88.196815] refill_obj_stock (mm/memcontrol.c:3339 (discriminator 2))
> > <4>[ 88.197367] obj_cgroup_uncharge (mm/memcontrol.c:3406)
> > <4>[ 88.197835] kmem_cache_free (include/linux/mm.h:1630
> > include/linux/mm.h:1849 include/linux/mm.h:1859 mm/slab.h:208
> > mm/slab.h:572 mm/slub.c:3804 mm/slub.c:3831)
> > <4>[ 88.198407] put_pid.part.0 (kernel/pid.c:118)
> > <4>[ 88.198870] delayed_put_pid (kernel/pid.c:127)
> > <4>[ 88.200527] rcu_core (arch/arm64/include/asm/preempt.h:13
> > (discriminator 1) kernel/rcu/tree.c:2146 (discriminator 1)
> > kernel/rcu/tree.c:2403 (discriminator 1))
>
> This all seems very surprising, especially given that AFAICT there are
> no changes in stable-6.6-rc for arch/arm64.

We do not see on the mainline and next.
Is this reported problems on stable-rc 6.6 and 6.5 are due to running
latest kselftest on older kernels ?

--
# # SSVE-VL-32-1: Mismatch: PID=641, iteration=0, reg=0
# # SSVE-VL-128-1: Got         [<junk>]
# # SSVE-VL-256-1: Got       [<junk>]

Unable to handle kernel paging request at virtual address 00740f0322740f02
0<1>[   89.400173] Mem abort info:
<1>[   89.400844]   ESR = 0x0000000096000004
<1>[   89.401974]   EC = 0x25: DABT (current EL), IL = 32 bits
<1>[   89.403399]   SET = 0, FnV = 0
<1>[   89.404421]   EA = 0, S1PTW = 0
<1>[   89.405317]   FSC = 0x04: level 0 translation fault
<1>[   89.406545] Data abort info:
<1>[   89.407493]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
<1>[   89.408785]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
<1>[   89.410001]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
<1>[   89.411485] [00740f0322740f02] address between user and kernel
address ranges
<0>[   89.413851] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
<4>[   89.415573] Modules linked in: crct10dif_ce sm3_ce sm3 sha3_ce
sha512_ce sha512_arm64 fuse drm dm_mod ip_tables x_tables
<4>[   89.419561] CPU: 1 PID: 22 Comm: ksoftirqd/1 Not tainted 6.5.11-rc1 #1
<4>[   89.420795] Hardware name: linux,dummy-virt (DT)
<4>[   89.422676] pstate: 624000c9 (nZCv daIF +PAN -UAO +TCO -DIT
-SSBS BTYPE=--)
<4>[   89.424344] pc : refill_obj_stock+0x6c/0x250
<4>[   89.426324] lr : refill_obj_stock+0x6c/0x250
<trim>
<4>[   89.447170] Call trace:
<4>[   89.447756]  refill_obj_stock+0x6c/0x250
<4>[   89.449033]  obj_cgroup_uncharge+0x20/0x38
<4>[   89.450457]  kmem_cache_free+0xf8/0x500
<4>[   89.451066]  delayed_put_pid+0x50/0xb0
<4>[   89.452401]  rcu_core+0x3cc/0x950
<4>[   89.453369]  rcu_core_si+0x1c/0x30
<4>[   89.454465]  __do_softirq+0x118/0x438
<4>[   89.455738]  run_ksoftirqd+0x40/0xf8
<4>[   89.456893]  smpboot_thread_fn+0x1d0/0x248
<4>[   89.457969]  kthread+0xfc/0x1a0
<4>[   89.459171]  ret_from_fork+0x10/0x20
<0>[   89.460445] Code: aa1603e0 97fffef8 aa0003f4 97f6cbf6 (f9400269)
<4>[   89.462028] ---[ end trace 0000000000000000 ]---
<0>[   89.463494] Kernel panic - not syncing: Oops: Fatal exception in interrupt
<2>[   89.465046] SMP: stopping secondary CPUs
<0>[   89.466327] Kernel Offset: 0x2dabffa00000 from 0xffff800080000000
<0>[   89.467385] PHYS_OFFSET: 0x40000000
<0>[   89.468131] CPU features: 0x00000000,68f167a1,cce6773f
<0>[   89.469850] Memory Limit: none
<0>[   89.470836] ---[ end Kernel panic - not syncing: Oops: Fatal
exception in interrupt ]---



Links:
https://qa-reports.linaro.org/lkft/linux-stable-rc-linux-6.5.y/build/v6.5.10-89-g73d52afec3ab/testrun/20963504/suite/log-parser-test/tests/
https://qa-reports.linaro.org/lkft/linux-stable-rc-linux-6.5.y/build/v6.5.10-89-g73d52afec3ab/testrun/20963709/suite/log-parser-test/tests/
https://qa-reports.linaro.org/lkft/linux-stable-rc-linux-6.5.y/build/v6.5.10-89-g73d52afec3ab/testrun/20963709/suite/log-parser-test/test/check-kernel-oops/log

- Naresh