Commit 24870a79 authored Mar 10, 2017 by bob picco Committed by Greg Kroah-Hartman May 03, 2017

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 bb4e6e85
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>

parent e88a8e0a

arch/sparc/mm/init_64.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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);