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From 75c7f5172c113af1ea3cf094436c9e03191673e0 Mon Sep 17 00:00:00 2001
From: Michael Ellerman <mpe@ellerman.id.au>
Date: Tue, 28 Nov 2017 11:26:55 +0100
Subject: [PATCH 2/5] powerpc/64s/hash: Fix 512T hint detection to use >= 128T
commit 7ece370996b694ae263025e056ad785afc1be5ab upstream.
Currently userspace is able to request mmap() search between 128T-512T
by specifying a hint address that is greater than 128T. But that means
a hint of 128T exactly will return an address below 128T, which is
confusing and wrong.
So fix the logic to check the hint is greater than *or equal* to 128T.
Fixes: f4ea6dcb08ea ("powerpc/mm: Enable mappings above 128TB")
Suggested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Split out of Nick's bigger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/mm/slice.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c
index 45f6740dd407..48a5312103a1 100644
--- a/arch/powerpc/mm/slice.c
+++ b/arch/powerpc/mm/slice.c
@@ -419,7 +419,7 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
/*
* Check if we need to expland slice area.
*/
- if (unlikely(addr > mm->context.addr_limit &&
+ if (unlikely(addr >= mm->context.addr_limit &&
mm->context.addr_limit != TASK_SIZE)) {
mm->context.addr_limit = TASK_SIZE;
on_each_cpu(slice_flush_segments, mm, 1);
@@ -427,7 +427,7 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
/*
* This mmap request can allocate upt to 512TB
*/
- if (addr > DEFAULT_MAP_WINDOW)
+ if (addr >= DEFAULT_MAP_WINDOW)
high_limit = mm->context.addr_limit;
else
high_limit = DEFAULT_MAP_WINDOW;
--
2.14.3
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