Re: Kernel oops with 6.14 when enabling TLS

[Hannes Reinecke <hare@suse.com>]

On 3/3/25 08:48, Hannes Reinecke wrote:
> On 2/28/25 11:47, Hannes Reinecke wrote:
>> Hi Sagi,
>>
>> enabling TLS on latest linus tree reliably crashes my system:
>>
>> [  487.018058] ------------[ cut here ]------------
>> [  487.024046] WARNING: CPU: 9 PID: 6159 at mm/slub.c:4719 
>> free_large_kmalloc+0x15/0xa0
[ .. ]
>>
>> Haven't found a culprit for that one for now, started bisecting.
>> Just wanted to report that as a heads-up, maybe you have some idea.
>>
> 
> bisect is pointing to
> 9aec2fb0fd5e ("slab: allocate frozen pages")
> and, indeed, reverting this patch on top of linus current resolves
> the issue.
> 
> Sorry Matthew.
> 
It's getting even worse; after reverting above patch I'm getting a crash
here:
[  968.315152] Oops: general protection fault, probably for 
non-canonical address 0xdead000000000120: 0000 [#1] PREE
MPT SMP NOPTI
[  968.328747] CPU: 30 UID: 0 PID: 665 Comm: kcompactd5 Kdump: loaded 
Tainted: G        W   E      6.14.0-rc4-defaul
t+ #306 9ca11b70f9498982db3664c8471cfe00b0a16485
[  968.345747] Tainted: [W]=WARN, [E]=UNSIGNED_MODULE
[  968.351913] Hardware name: Lenovo ThinkSystem SR655V3/SB27B09914, 
BIOS KAE111E-2.10 04/11/2023
[  968.362371] RIP: 0010:isolate_movable_page+0x7c/0x130
[  968.368826] Code: 02 75 3c f0 48 0f ba 2b 00 72 34 48 89 df e8 8b e0 
f6 ff 84 c0 74 20 48 8b 03 a9 00 00 01 00 75
  16 48 8b 43 18 89 ee 48 89 df <48> 8b 40 fe ff d0 0f 1f 00 84 c0 75 61 
48 89 df e8 ff d8 f2 ff f0
[  968.390698] RSP: 0018:ff582840034c7bd0 EFLAGS: 00010246
[  968.397354] RAX: dead000000000122 RBX: ffc1af3dcf400000 RCX: 
ffc1af3dcf400034
[  968.406145] RDX: dead000000000101 RSI: 000000000000000c RDI: 
ffc1af3dcf400000
[  968.414950] RBP: 000000000000000c R08: 0000000000000000 R09: 
000000000f400000
[  968.423755] R10: 0000000000000400 R11: ff4187a00d995780 R12: 
00000000003d0000
[  968.432562] R13: ff582840034c7d30 R14: 0000000000000001 R15: 
0000000000000001
[  968.441365] FS:  0000000000000000(0000) GS:ff41879ffaa00000(0000) 
knlGS:0000000000000000
[  968.451245] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  968.458488] CR2: 000055b303833c20 CR3: 000000005a838002 CR4: 
0000000000771ef0
[  968.467295] PKRU: 55555554
[  968.471120] Call Trace:
[  968.474655]  <TASK>
[  968.477804]  ? __die_body+0x1a/0x60
[  968.482521]  ? die_addr+0x38/0x60
[  968.487030]  ? exc_general_protection+0x19e/0x430
[  968.493115]  ? asm_exc_general_protection+0x22/0x30
[  968.499395]  ? isolate_movable_page+0x7c/0x130
[  968.505180]  isolate_migratepages_block+0x39a/0x1090
[  968.511555]  ? srso_alias_return_thunk+0x5/0xfbef5
[  968.517728]  ? update_curr+0x19e/0x220
[  968.522725]  compact_zone+0x368/0x1090
[  968.527722]  ? srso_alias_return_thunk+0x5/0xfbef5
[  968.533896]  compact_node+0xa8/0x120
[  968.538720]  kcompactd+0x21e/0x2b0

which again points straight into the 'allocate and free frozen pages'
patchset. Something's buggered there, and I'm not sure if further
bisecting will be getting us anywhere.

Matt?

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.com                               +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich