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>

diff --git a/arch/tile/mm/init.c b/arch/tile/mm/init.c
index ace32d7..5bd252e 100644 (file)
--- 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 &&