proc/kcore: add vmcoreinfo note to /proc/kcore

The vmcoreinfo information is useful for runtime debugging tools, not just
for crash dumps.  A lot of this information can be determined by other
means, but this is much more convenient, and it only adds a page at most
to the file.

Link: http://lkml.kernel.org/r/fddbcd08eed76344863303878b12de1c1e2a04b6.1531953780.git.osandov@fb.com
Signed-off-by: Omar Sandoval <osandov@fb.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index e7b4025..a683bfb 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -14,8 +14,8 @@
 #include <asm/sections.h>
 
 /* vmcoreinfo stuff */
-static unsigned char *vmcoreinfo_data;
-static size_t vmcoreinfo_size;
+unsigned char *vmcoreinfo_data;
+size_t vmcoreinfo_size;
 u32 *vmcoreinfo_note;
 
 /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */