From 24870a79dad693214b21558388cb04dad6159aa3 Mon Sep 17 00:00:00 2001
From: bob picco <bob.picco@oracle.com>
Date: Fri, 10 Mar 2017 14:31:19 -0500
Subject: sparc64: kern_addr_valid regression

[ Upstream commit adfae8a5d833fa2b46577a8081f350e408851f5b ]

I encountered this bug when using /proc/kcore to examine the kernel. Plus a
coworker inquired about debugging tools. We computed pa but did
not use it during the maximum physical address bits test. Instead we used
the identity mapped virtual address which will always fail this test.

I believe the defect came in here:
[bpicco@zareason linus.git]$ git describe --contains bb4e6e85daa52
v3.18-rc1~87^2~4
.

Signed-off-by: Bob Picco <bob.picco@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 37aa537..bd7e2aa 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -1495,7 +1495,7 @@ bool kern_addr_valid(unsigned long addr)
 	if ((long)addr < 0L) {
 		unsigned long pa = __pa(addr);
 
-		if ((addr >> max_phys_bits) != 0UL)
+		if ((pa >> max_phys_bits) != 0UL)
 			return false;
 
 		return pfn_valid(pa >> PAGE_SHIFT);
-- 
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