Kernel bug in 5.7 for PPC32 on PowerBook G4 - bisected to commit 697ece7
Hi Christophe,
Although kernel 5.7.0-rc2 appeared to boot cleanly, it failed on my G4 when I
tried to generate a new kernel. The following BUG message is logged:
[ 336.148935] [ cut here ]
[ 336.148950] kernel BUG at ./include/linux/swapops.h:195!
[ 336.148971] Oops: Exception in kernel mode, sig: 5 [#1]
[ 336.148975] BE PAGE_SIZE=4K MMU=Hash PowerMac
[ 336.148978] Modules linked in: cpufreq_ondemand fuse ctr ccm b43 mac80211
sha256_generic libsha256 cfg80211 hid_apple hid_generic joydev rfkill libarc4
rng_core cordic uinput radeon evdev
ttm drm_kms_helper usbhid hid appletouch drm rack_meter ehci_pci ehci_hcd
drm_panel_orientation_quirks ssb fb_sys_fops yenta_socket sysimgblt sysfillrect
pcmcia_rsrc syscopyarea pcmcia pcmcia
_core i2c_powermac therm_adt746x loop ohci_pci ohci_hcd usbcore sungem
sungem_phy usb_common
[ 336.149052] CPU: 0 PID: 8346 Comm: ld Not tainted 5.6.0-rc2-00086-g36b7840
#249
[ 336.149056] NIP: c0166624 LR: c016661c CTR:
[ 336.149062] REGS: f42ddb08 TRAP: 0700 Not tainted
(5.6.0-rc2-00086-g36b7840)
[ 336.149064] MSR: 00029032 CR: 24000424 XER:
[ 336.149072]
[ 336.149072] GPR00: f42ddbc0 c24fcb80 0001 ef438f00 c1957b1c
f42ddc4c 0004
[ 336.149072] GPR08: 0050 0100 edb9d000 100cba68
10051b10 10051b08
[ 336.149072] GPR16: 01be ee68c078 105a c1957b1c
[ 336.149072] GPR24: ec5d2540 7c002bf8 c1957ae0 ec5d2540
ef438f00 ef438f00
[ 336.149107] NIP [c0166624] _einittext+0x3f9d38a8/0x3fe4a284
[ 336.149111] LR [c016661c] _einittext+0x3f9d38a0/0x3fe4a284
[ 336.149114] Call Trace:
[ 336.149118] [f42ddbc0] [c07b9b60] 0xc07b9b60 (unreliable)
[ 336.149123] [f42ddbd0] [c013ff64] _einittext+0x3f9ad1e8/0x3fe4a284
[ 336.149128] [f42ddc10] [c0140d4c] _einittext+0x3f9adfd0/0x3fe4a284
[ 336.149133] [f42ddc90] [c002aadc] _einittext+0x3f897d60/0x3fe4a284
[ 336.149137] [f42ddce0] [c00153a4] _einittext+0x3f882628/0x3fe4a284
[ 336.149144] --- interrupt: 301 at _einittext+0x3fb52a50/0x3fe4a284
[ 336.149144] LR = _einittext+0x3fb52a4c/0x3fe4a284
[ 336.149148] [f42ddda8] [c02e56c0] _einittext+0x3fb52944/0x3fe4a284
(unreliable)
[ 336.149153] [f42ddde8] [c011644c] _einittext+0x3f9836d0/0x3fe4a284
[ 336.149158] [f42dde38] [c01f5950] _einittext+0x3fa62bd4/0x3fe4a284
[ 336.149163] [f42dde58] [c016b98c] _einittext+0x3f9d8c10/0x3fe4a284
[ 336.149167] [f42ddec8] [c016ba60] _einittext+0x3f9d8ce4/0x3fe4a284
[ 336.149172] [f42ddef8] [c016bd00] _einittext+0x3f9d8f84/0x3fe4a284
[ 336.149177] [f42ddf38] [c0015174] _einittext+0x3f8823f8/0x3fe4a284
[ 336.149182] --- interrupt: c01 at 0xfdf99fc
[ 336.149182] LR = 0xfd9cce0
[ 336.149184] Instruction dump:
[ 336.149189] 40be0018 4bffe359 3c80c06a 3884e48f 4bfd4c9d 0fe0 4bffe345
7c641b78
[ 336.149196] 3860 4bffe045 7c630034 5463d97e <0f03> 3940 393f001c
3961
[ 336.149208] ---[ end trace d08833cae9c66ce3 ]---
[ 336.149210]
[ 336.193729] [ cut here ]
This problem was bisected to commit 697ece7 ("powerpc/32s: reorder Linux PTE
bits to better match Hash PTE bits").
If I had done more rigorous tests earlier, I would have found the bug with more
time to fix it before release of 5.7, but every other problem I have found
happened at boot, not when the machine had to swap.
Thanks,
Larry
Re: Kernel bug in 5.7 for PPC32 on PowerBook G4 - bisected to commit 697ece7
Hi Larry,
Le 23/05/2020 à 19:24, Larry Finger a écrit :
Hi Christophe,
Although kernel 5.7.0-rc2 appeared to boot cleanly, it failed on my G4
when I tried to generate a new kernel. The following BUG message is logged:
[...]
This problem was bisected to commit 697ece7 ("powerpc/32s: reorder Linux
PTE bits to better match Hash PTE bits").
Being reversed in new -rc , see
https://patchwork.ozlabs.org/project/linuxppc-dev/patch/87sgfsf4hs@mpe.ellerman.id.au/
If I had done more rigorous tests earlier, I would have found the bug
with more time to fix it before release of 5.7, but every other problem
I have found happened at boot, not when the machine had to swap.
Thanks,
Larry
Christophe
Re: Kernel bug in 5.7 for PPC32 on PowerBook G4 - bisected to commit 697ece7
On 5/23/20 12:30 PM, Christophe Leroy wrote:
Hi Larry,
Le 23/05/2020 à 19:24, Larry Finger a écrit :
Hi Christophe,
Although kernel 5.7.0-rc2 appeared to boot cleanly, it failed on my G4 when I
tried to generate a new kernel. The following BUG message is logged:
[...]
This problem was bisected to commit 697ece7 ("powerpc/32s: reorder Linux PTE
bits to better match Hash PTE bits").
Being reversed in new -rc , see
https://patchwork.ozlabs.org/project/linuxppc-dev/patch/87sgfsf4hs@mpe.ellerman.id.au/
Christophe,
Thanks for the update.
Larry
