On Sat, 2018-03-31 at 11:51:38 UTC, Michael Ellerman wrote:
> On 64-bit Book3E systems, in setup_tlb_core_data() we reference other
> CPUs pacas. But in commit 59f577743d71 ("powerpc/64: Defer paca
> allocation until memory topology is discovered") the allocation of
> non-boot-CPU pacas was deferred until later in boot.
>
> This leads to an oops:
>
> CPU maps initialized for 1 thread per core
> Unable to handle kernel paging request for data at address
> 0x8888888888888918
> Faulting instruction address: 0xc000000000e2f0d0
> Oops: Kernel access of bad area, sig: 11 [#1]
> NIP .setup_tlb_core_data+0xdc/0x160
> Call Trace:
> .setup_tlb_core_data+0x5c/0x160 (unreliable)
> .setup_arch+0x80/0x348
> .start_kernel+0x7c/0x598
> start_here_common+0x1c/0x40
>
> Luckily setup_tlb_core_data() is called immediately prior to
> smp_setup_pacas(). So simply switching their order is sufficient to
> fix the oops and seems unlikely to have any other unwanted side
> effects.
>
> Fixes: 59f577743d71 ("powerpc/64: Defer paca allocation until memory topology
> is discovered")
> Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
Applied to powerpc next.
https://git.kernel.org/powerpc/c/1d0afc0d5a7c281f8ced3bd39f61f3
cheers
