Hi,
On Tue, 2025-08-12 at 18:03 +0000, Edgecombe, Rick P wrote:
> On Tue, 2025-08-12 at 18:43 +0200, John Paul Adrian Glaubitz wrote:
> > I suspect that the main issue is to be found in the following patch which
> > introduced VM_FLUSH_RESET_PERMS
> > which may not work as expected on sun4u SPARC systems:
>
> I think the problem we found with VM_FLUSH_RESET_PERMS was that the sparc64
> kernel TLB flush implementation was broken. Since VM_FLUSH_RESET_PERMS caused
> kernel TLB flushes to happen sooner, it just showed up sooner. [0]
>
> This other issue seems to be about userspace memory. So I wonder if these are
> two separate issues? Bisecting to the original VM_FLUSH_RESET_PERMS would have
> had the known sparc kernel range TLB flush issue. So to bisect the other issue
> you might need to apply this [1].
That could be true. I knew about the patch in [1] but I didn't think of
applying it.
FWIW, the crashes we're seeing on recent kernel versions look like this:
[ 40.992851] \|/ ____ \|/
[ 40.992851] "@'/ .. \`@"
[ 40.992851] /_| \__/ |_\
[ 40.992851] \__U_/
[ 41.186220] (udev-worker)(88): Kernel illegal instruction [#1]
[ 41.262910] CPU: 0 UID: 0 PID: 88 Comm: (udev-worker) Tainted: G W
6.12.0+ #25
[ 41.376151] Tainted: [W]=WARN
[ 41.415025] TSTATE: 0000004411001607 TPC: 00000000101c21c0 TNPC:
00000000101c21c4 Y: 00000000 Tainted: G W
[ 41.563717] TPC: <ehci_init_driver+0x0/0x160 [ehci_hcd]>
[ 41.633584] g0: 00000000012005b8 g1: 00000000100a1800 g2: 0000000010206000
g3: 00000000101de000
[ 41.747962] g4: fff000000a5af380 g5: 0000000000000000 g6: fff000000aac8000
g7: 0000000000000e7b
[ 41.862338] o0: 0000000010060118 o1: 000000001020a000 o2: fff000000aa30ce0
o3: 0000000000000e7a
[ 41.976728] o4: 00000000ff000000 o5: 00ff000000000000 sp: fff000000aacb091
ret_pc: 00000000101de028
[ 42.095768] RPC: <ehci_pci_init+0x28/0x2000 [ehci_pci]>
[ 42.164394] l0: 0000000000000000 l1: 0000000100043fff l2: ffffffffff800000
l3: 0000000000800000
[ 42.278768] l4: fff00000001c8008 l5: 0000000000000000 l6: 00000000013358e0
l7: 0000000001002800
[ 42.393143] i0: ffffffffffffffed i1: 00000000004db8d8 i2: 0000000000000000
i3: fff000000aa304e0
[ 42.507517] i4: 0000000001127250 i5: 0000000010060000 i6: fff000000aacb141
i7: 0000000000427d90
[ 42.621893] I7: <do_one_initcall+0x30/0x200>
[ 42.677931] Call Trace:
[ 42.709953] [<0000000000427d90>] do_one_initcall+0x30/0x200
[ 42.783158] [<00000000004db908>] do_init_module+0x48/0x240
[ 42.855214] [<00000000004dd82c>] load_module+0x19cc/0x1f20
[ 42.927270] [<00000000004ddf8c>] init_module_from_file+0x6c/0xa0
[ 43.006189] [<00000000004de1e4>] sys_finit_module+0x1c4/0x2c0
[ 43.081677] [<0000000000406174>] linux_sparc_syscall+0x34/0x44
[ 43.158307] Disabling lock debugging due to kernel taint
[ 43.228077] Caller[0000000000427d90]: do_one_initcall+0x30/0x200
[ 43.306995] Caller[00000000004db908]: do_init_module+0x48/0x240
[ 43.384772] Caller[00000000004dd82c]: load_module+0x19cc/0x1f20
[ 43.462544] Caller[00000000004ddf8c]: init_module_from_file+0x6c/0xa0
[ 43.547184] Caller[00000000004de1e4]: sys_finit_module+0x1c4/0x2c0
[ 43.628389] Caller[0000000000406174]: linux_sparc_syscall+0x34/0x44
[ 43.710741] Caller[fff000010480e2fc]: 0xfff000010480e2fc
[ 43.780508] Instruction DUMP:
[ 43.780511] 00000000
[ 43.819394] 00000000
[ 43.850273] 00000000
[ 43.881153] <00000000>
[ 43.912036] 00000000
[ 43.942917] 00000000
[ 43.973797] 00000000
[ 44.004678] 00000000
[ 44.035561] 00000000
[ 44.066443]
Do you have any suggestion what to bisect?
Adrian
--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer
`. `' Physicist
`- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
