From: Andrea Arcangeli aarcange@redhat.com
[ Upstream commit 03800e0526ee25ed7c843ca1e57b69ac2a5af642 ]
25078dc1f74be16b858e914f52cc8f4d03c2271a first introduced an off by one error in the ZONE_DMA initialization of PPC_BOOK3E_64=y and since 9739ab7eda459f0669ec9807e0d9be5020bab88c the off by one applies to PPC32=y too. This simply corrects the off by one and should resolve crashes like below:
[ 65.179101] page 0x7fff outside node 0 zone DMA [ 0x0 - 0x7fff ]
Unfortunately in various MM places "max" means a non inclusive end of range. free_area_init_nodes max_zone_pfn parameter is one case and MAX_ORDER is another one (unrelated) that comes by memory.
Reported-by: Zorro Lang zlang@redhat.com Fixes: 25078dc1f74b ("powerpc: use mm zones more sensibly") Fixes: 9739ab7eda45 ("powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac") Signed-off-by: Andrea Arcangeli aarcange@redhat.com Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20190625141727.2883-1-aarcange@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/mm/mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index 2540d3b2588c3..2eda1ec36f552 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -249,7 +249,7 @@ void __init paging_init(void)
#ifdef CONFIG_ZONE_DMA max_zone_pfns[ZONE_DMA] = min(max_low_pfn, - ((1UL << ARCH_ZONE_DMA_BITS) - 1) >> PAGE_SHIFT); + 1UL << (ARCH_ZONE_DMA_BITS - PAGE_SHIFT)); #endif max_zone_pfns[ZONE_NORMAL] = max_low_pfn; #ifdef CONFIG_HIGHMEM