tile: map data region shadow of kernel as R/W

This is necessary for things like reading /proc/kcore, doing ftrace,
etc.  It happens by default when using huge pages to map the kernel
data, but not when using small pages.

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/arch/tile/mm/init.c b/arch/tile/mm/init.c
index ace32d7d3864..5bd252e3fdc5 100644
--- a/arch/tile/mm/init.c
+++ b/arch/tile/mm/init.c
@@ -233,9 +233,12 @@ static pgprot_t __init init_pgprot(ulong address)
         if (kdata_huge)
                 return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
 
-        /* We map the aliased pages of permanent text inaccessible. */
+        /*
+         * We map the aliased pages of permanent text so we can
+         * update them if necessary, for ftrace, etc.
+         */
         if (address < (ulong) _sinittext - CODE_DELTA)
-                return PAGE_NONE;
+                return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
 
         /* We map read-only data non-coherent for performance. */
         if ((address >= (ulong) __start_rodata &&