Patch "sparc64: kern_addr_valid regression" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

sparc64: kern_addr_valid regression

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
sparc64-kern_addr_valid-regression.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: bob picco <[email protected]>
Date: Fri, 10 Mar 2017 14:31:19 -0500
Subject: sparc64: kern_addr_valid regression

From: bob picco <[email protected]>

[ 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
.

---
 arch/sparc/mm/init_64.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -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);

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/sparc64-kern_addr_valid-regression.patch