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* [PATCH AUTOSEL 5.2 01/76] powerpc: fix off by one in max_zone_pfn initialization for ZONE_DMA
@ 2019-08-02 13:18 Sasha Levin
  2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 37/76] powerpc/papr_scm: Force a scm-unbind if initial scm-bind fails Sasha Levin
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Sasha Levin @ 2019-08-02 13:18 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Andrea Arcangeli, Sasha Levin, Zorro Lang, linuxppc-dev,
	Christoph Hellwig

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
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2019-08-02 13:44 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-08-02 13:18 [PATCH AUTOSEL 5.2 01/76] powerpc: fix off by one in max_zone_pfn initialization for ZONE_DMA Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 37/76] powerpc/papr_scm: Force a scm-unbind if initial scm-bind fails Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 46/76] cpufreq/pasemi: fix use-after-free in pas_cpufreq_cpu_init() Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 65/76] scsi: ibmvfc: fix WARN_ON during event pool release Sasha Levin

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