[IA64] Fill holes in FIXADDR_USER space with zero pages.
David Mosberger-Tang [Wed, 8 Jun 2005 17:45:00 +0000 (10:45 -0700)]
This fixes an oops reported by Jason Baron.

Signed-off-by: David Mosberger-Tang <davidm@hpl.hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/mm/init.c
include/asm-ia64/pgtable.h

index 547785e..4eb2f52 100644 (file)
@@ -305,8 +305,9 @@ setup_gate (void)
        struct page *page;
 
        /*
-        * Map the gate page twice: once read-only to export the ELF headers etc. and once
-        * execute-only page to enable privilege-promotion via "epc":
+        * Map the gate page twice: once read-only to export the ELF
+        * headers etc. and once execute-only page to enable
+        * privilege-promotion via "epc":
         */
        page = virt_to_page(ia64_imva(__start_gate_section));
        put_kernel_page(page, GATE_ADDR, PAGE_READONLY);
@@ -315,6 +316,20 @@ setup_gate (void)
        put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE);
 #else
        put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE);
+       /* Fill in the holes (if any) with read-only zero pages: */
+       {
+               unsigned long addr;
+
+               for (addr = GATE_ADDR + PAGE_SIZE;
+                    addr < GATE_ADDR + PERCPU_PAGE_SIZE;
+                    addr += PAGE_SIZE)
+               {
+                       put_kernel_page(ZERO_PAGE(0), addr,
+                                       PAGE_READONLY);
+                       put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE,
+                                       PAGE_READONLY);
+               }
+       }
 #endif
        ia64_patch_gate();
 }
index ea121a0..fcc9c33 100644 (file)
@@ -8,7 +8,7 @@
  * This hopefully works with any (fixed) IA-64 page-size, as defined
  * in <asm/page.h>.
  *
- * Copyright (C) 1998-2004 Hewlett-Packard Co
+ * Copyright (C) 1998-2005 Hewlett-Packard Co
  *     David Mosberger-Tang <davidm@hpl.hp.com>
  */
 
@@ -551,7 +551,11 @@ do {                                                                                       \
 
 /* These tell get_user_pages() that the first gate page is accessible from user-level.  */
 #define FIXADDR_USER_START     GATE_ADDR
-#define FIXADDR_USER_END       (GATE_ADDR + 2*PERCPU_PAGE_SIZE)
+#ifdef HAVE_BUGGY_SEGREL
+# define FIXADDR_USER_END      (GATE_ADDR + 2*PAGE_SIZE)
+#else
+# define FIXADDR_USER_END      (GATE_ADDR + 2*PERCPU_PAGE_SIZE)
+#endif
 
 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY