This is a note to let you know that I've just added the patch titled sparc32: Limit memblock allocation to low memory to the 5.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: sparc32-limit-memblock-allocation-to-low-memory.patch and it can be found in the queue-5.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 0ad4bd3b84faf49b8a967ef06f8118557bb57b44 Author: Andreas Larsson <andreas@xxxxxxxxxxx> Date: Fri Feb 5 14:20:31 2021 +0100 sparc32: Limit memblock allocation to low memory [ Upstream commit bda166930c37604ffa93f2425426af6921ec575a ] Commit cca079ef8ac29a7c02192d2bad2ffe4c0c5ffdd0 changed sparc32 to use memblocks instead of bootmem, but also made high memory available via memblock allocation which does not work together with e.g. phys_to_virt and can lead to kernel panic. This changes back to only low memory being allocatable in the early stages, now using memblock allocation. Signed-off-by: Andreas Larsson <andreas@xxxxxxxxxxx> Acked-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c index eb2946b1df8a..6139c5700ccc 100644 --- a/arch/sparc/mm/init_32.c +++ b/arch/sparc/mm/init_32.c @@ -197,6 +197,9 @@ unsigned long __init bootmem_init(unsigned long *pages_avail) size = memblock_phys_mem_size() - memblock_reserved_size(); *pages_avail = (size >> PAGE_SHIFT) - high_pages; + /* Only allow low memory to be allocated via memblock allocation */ + memblock_set_current_limit(max_low_pfn << PAGE_SHIFT); + return max_pfn; }