On Mon, Oct 21, 2024 at 05:35:35PM +1100, Michael Ellerman wrote:
> Guenter Roeck <linux@xxxxxxxxxxxx> writes:
> > Hi,
>
> Hi Guenter,
>
> Thanks for the report.
>
> > On 10/15/24 04:19, Greg Kroah-Hartman wrote:
> >> This is the start of the stable review cycle for the 5.15.168 release.
> >> There are 691 patches in this series, all will be posted as a response
> >> to this one. If anyone has any issues with these being applied, please
> >> let me know.
> >>
> >> Responses should be made by Thu, 17 Oct 2024 11:22:41 +0000.
> >> Anything received after that time might be too late.
> >>
> > ...
> >> Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> >> powerpc/mm: Fix boot warning with hugepages and CONFIG_DEBUG_VIRTUAL
> >>
> >
> > This patch triggers a crash when trying to boot various powerpc images.
> >
> > ------------[ cut here ]------------
> > kernel BUG at include/linux/scatterlist.h:143!
> > Oops: Exception in kernel mode, sig: 5 [#1]
> > BE PAGE_SIZE=4K MMU=Hash PREEMPT SMP NR_CPUS=32 NUMA PowerMac
> > Modules linked in:
> > CPU: 0 PID: 25 Comm: cryptomgr_test Not tainted 5.15.167-00018-g00ef1de6d646 #1
> > NIP: c00000000082c6c0 LR: c00000000082f460 CTR: 0000000000000000
> > REGS: c00000000962b540 TRAP: 0700 Not tainted (5.15.167-00018-g00ef1de6d646)
> > MSR: 8000000000028032 <SF,EE,IR,DR,RI> CR: 84000440 XER: 20000000
> > IRQMASK: 0
> > GPR00: c00000000082f44c c00000000962b7e0 c000000001ef6c00 c00000000962b9e8
> > GPR04: c0000000096e2000 0000000000000008 c00000000962ba48 0000000000000200
> > GPR08: 000000003e2a5000 c000000000000000 0000000000000000 0000000000000001
> > GPR12: 0000000024000440 c000000002b62000 c00000000011e6b0 c0000000096c8e40
> > GPR16: 0000000000000000 c00000000148c300 c00000000148c2f0 0000000000000008
> > GPR20: 0000000000000040 c00000000147ddf8 0000000000000040 c00000000956f4a8
> > GPR24: c000000002a23c98 c000000001417d18 c0000000096e2000 0000000000000001
> > GPR28: 0000000000000008 c00000000962b9e8 00000000000096e2 c0000000096e2000
> > NIP [c00000000082c6c0] .sg_set_buf+0x50/0x350
> > LR [c00000000082f460] .test_akcipher_one+0x280/0x860
> > Call Trace:
> > [c00000000962b7e0] [c00000000956f4f3] 0xc00000000956f4f3 (unreliable)
> > [c00000000962b890] [c00000000082f44c] .test_akcipher_one+0x26c/0x860
> > [c00000000962bad0] [c00000000082fb14] .alg_test_akcipher+0xd4/0x150
> > [c00000000962bb70] [c00000000082bcac] .alg_test+0x15c/0x640
> > [c00000000962bcd0] [c000000000829850] .cryptomgr_test+0x40/0x70
> > [c00000000962bd50] [c00000000011e880] .kthread+0x1d0/0x1e0
> > [c00000000962be10] [c00000000000cc60] .ret_from_kernel_thread+0x58/0x60
> > Instruction dump:
> > fbe1fff8 6129ffff fb61ffd8 7c244840 7c9f2378 91810008 7c7d1b78 f821ff51
> > 7cbc2b78 789ea402 41810078 3b600001 <0b1b0000> 3d220007 7bde3664 39492f20
> > ---[ end trace fdddc57d958f029f ]---
> >
> > The problem affects v5.15.168 and v5.10.227. Reverting the offending patch
> > fixes the problem in both branches.
> >
> > My test images do not have hugepages or CONFIG_DEBUG_VIRTUAL enabled.
> >
> > Bisect log is attached. I copied the author and Michael for comments.
>
> I don't see that exact oops, but some others, which all track back to
> the same source.
>
> The offending commit includes:
>
> high_memory is set in mem_init() using max_low_pfn, but max_low_pfn
> is available long before, it is set in mem_topology_setup().
>
> But that's only been true since commit:
>
> 7b31f7dadd70 ("powerpc/mm: Always update max/min_low_pfn in mem_topology_setup()")
>
> which went into v6.1.
>
> Backporting that commit to v5.15 (and v5.10) fixes the oops for me, and
> otherwise looks safe to backport.
>
> Greg can you pick that commit (7b31f7dadd70) up for v5.15 and v5.10 please?
Now picked up, thanks!
greg k-h
