[1/2] powerpc/mm: Check memblock_add against MAX_PHYSMEM_BITS range

[Michael Ellerman]

On Thu, 2018-06-21 at 08:31:57 UTC, "Aneesh Kumar K.V" wrote:
> With SPARSEMEM config enabled, we make sure that we don't add sections beyond
> MAX_PHYSMEM_BITS range. This results in not building vmemmap mapping for
> range beyond max range. But our memblock layer looks the device tree and create
> mapping for the full memory range. Prevent this by checking against
> MAX_PHSYSMEM_BITS when doing memblock_add.
> 
> We don't do similar check for memeblock_reserve_range. If reserve range is beyond
> MAX_PHYSMEM_BITS we expect that to be configured with 'nomap'. Any other
> reserved range should come from existing memblock ranges which we already
> filtered while adding.
> 
> This avoids crash as below when running on a system with system ram config above
> MAX_PHSYSMEM_BITS
> 
>  Unable to handle kernel paging request for data at address 0xc00a001000000440
>  Faulting instruction address: 0xc000000001034118
>  cpu 0x0: Vector: 300 (Data Access) at [c00000000124fb30]
>      pc: c000000001034118: __free_pages_bootmem+0xc0/0x1c0
>      lr: c00000000103b258: free_all_bootmem+0x19c/0x22c
>      sp: c00000000124fdb0
>     msr: 9000000002001033
>     dar: c00a001000000440
>   dsisr: 40000000
>    current = 0xc00000000120dd00
>    paca    = 0xc000000001f60000^I irqmask: 0x03^I irq_happened: 0x01
>      pid   = 0, comm = swapper
>  [c00000000124fe20] c00000000103b258 free_all_bootmem+0x19c/0x22c
>  [c00000000124fee0] c000000001010a68 mem_init+0x3c/0x5c
>  [c00000000124ff00] c00000000100401c start_kernel+0x298/0x5e4
>  [c00000000124ff90] c00000000000b57c start_here_common+0x1c/0x520
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>

Series applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/6aba0c84ec474534bbae3675e95464

cheers