The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f24e5834a2c3f6c5f814a417f858226f0a010ade Mon Sep 17 00:00:00 2001
From: Steve Capper steve.capper@arm.com Date: Mon, 4 Dec 2017 14:13:05 +0000 Subject: [PATCH] arm64: Initialise high_memory global variable earlier
The high_memory global variable is used by cma_declare_contiguous(.) before it is defined.
We don't notice this as we compute __pa(high_memory - 1), and it looks like we're processing a VA from the direct linear map.
This problem becomes apparent when we flip the kernel virtual address space and the linear map is moved to the bottom of the kernel VA space.
This patch moves the initialisation of high_memory before it used.
Cc: stable@vger.kernel.org Fixes: f7426b983a6a ("mm: cma: adjust address limit to avoid hitting low/high memory boundary") Signed-off-by: Steve Capper steve.capper@arm.com Signed-off-by: Will Deacon will.deacon@arm.com
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 5960bef0170d..00e7b900ca41 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -476,6 +476,8 @@ void __init arm64_memblock_init(void)
reserve_elfcorehdr();
+ high_memory = __va(memblock_end_of_DRAM() - 1) + 1; + dma_contiguous_reserve(arm64_dma_phys_limit);
memblock_allow_resize(); @@ -502,7 +504,6 @@ void __init bootmem_init(void) sparse_init(); zone_sizes_init(min, max);
- high_memory = __va((max << PAGE_SHIFT) - 1) + 1; memblock_dump_all(); }