* Sven Schnelle <svens@xxxxxxxxxxxxx> [230110 09:54]:
> Liam Howlett <liam.howlett@xxxxxxxxxx> writes:
>
> > From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
> >
> > Start passing the vma iterator through the mm code. This will allow for
> > reuse of the state and cleaner invalidation if necessary.
> >
> > Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
> > ---
> > include/linux/mm.h | 2 +-
> > mm/mmap.c | 77 +++++++++++++++++++++-------------------------
> > mm/mremap.c | 6 ++--
> > 3 files changed, 39 insertions(+), 46 deletions(-)
> >
>
> Starting with this patch i see the following oops on s390:
>
> [ 4.512863] Run /sbin/init as init process
> [ 4.519447] Unable to handle kernel pointer dereference in virtual kernel address space
> [ 4.519450] Failing address: fbebfffb00000000 TEID: fbebfffb00000803
> [ 4.519452] Fault in home space mode while using kernel ASCE.
> [ 4.519455] AS:0000000001a60007 R3:0000000000000024
> [ 4.519482] Oops: 0038 ilc:2 [#1] SMP
> [ 4.519486] Modules linked in:
> [ 4.519488] CPU: 7 PID: 1 Comm: init Not tainted 6.2.0-rc1-00179-ga7f83eb601ef #1582
> [ 4.519491] Hardware name: IBM 3906 M04 704 (z/VM 7.1.0)
> [ 4.519493] Krnl PSW : 0704c00180000000 0000000000929464 (__memcpy+0x24/0x50)
> [ 4.519503] R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
> [ 4.519506] Krnl GPRS: 0000000000000000 0000037fffb1f990 0000037fffb1f990 fbebfffb00000008
> [ 4.519509] 0000000000000007 0000000000929480 0000000000000008 0000000000000000
> [ 4.519517] 0000000000000009 0000037fffb1fb40 0000037fffb1f880 0000037fffb1fc58
> [ 4.519519] 0000000080288000 0000000000000001 0000000000cf65da 0000037fffb1f5d8
> [ 4.519527] Krnl Code: 0000000000929456: b9040012 lgr %r1,%r2
> [ 4.519527] 000000000092945a: a7740008 brc 7,000000000092946a
> [ 4.519527] #000000000092945e: c05000000011 larl %r5,0000000000929480
> [ 4.519527] >0000000000929464: 44405000 ex %r4,0(%r5)
> [ 4.519527] 0000000000929468: 07fe bcr 15,%r14
> [ 4.519527] 000000000092946a: d2ff10003000 mvc 0(256,%r1),0(%r3)
> [ 4.519527] 0000000000929470: 41101100 la %r1,256(%r1)
> [ 4.519527] 0000000000929474: 41303100 la %r3,256(%r3)
> [ 4.519547] Call Trace:
> [ 4.519548] [<0000000000929464>] __memcpy+0x24/0x50
> [ 4.519557] [<0000000000cfd474>] mas_wr_bnode+0x5c/0x14e8
> [ 4.519562] [<0000000000cffaf6>] mas_store_prealloc+0x4e/0xf8
> [ 4.519569] [<000000000039d262>] mmap_region+0x482/0x8b0
> [ 4.519572] [<000000000039da6e>] do_mmap+0x3de/0x4c0
> [ 4.519575] [<000000000036aeae>] vm_mmap_pgoff+0xd6/0x188
> [ 4.519580] [<000000000039a18a>] ksys_mmap_pgoff+0x62/0x230
> [ 4.519584] [<000000000039a522>] __s390x_sys_old_mmap+0x7a/0x98
> [ 4.519588] [<0000000000d22650>] __do_syscall+0x1d0/0x1f8
> [ 4.519592] [<0000000000d32712>] system_call+0x82/0xb0
> [ 4.519596] Last Breaking-Event-Address:
> [ 4.519596] [<0000000000cf65d4>] mas_store_b_node+0x3cc/0x6b0
> [ 4.519603] Kernel panic - not syncing: Fatal exception: panic_on_oops
>
> This happens on every boot, always killing the init process. The oops
> doesn't happen with next-20230110. With next-20230110 i see shmat
> testcase failures in ltp (shmat returning with -EINVAL because
> find_vma_intersection() tells shmat that there's already a mapping
> present).
>
> Trying to bisect that i stumbled above the oops above. Any ideas before
> i start trying to understand the patch?
Yes, try the patch for fixing the invalidated state I sent out yesterday
[1]. This should come before ("mm: expand vma iterator interface").
1. https://lore.kernel.org/linux-mm/20230109165455.647400-1-Liam.Howlett@xxxxxxxxxx/
