Commit ad597bd5 authored by David Mosberger-Tang's avatar David Mosberger-Tang Committed by Tony Luck
Browse files

[IA64] Fill holes in FIXADDR_USER space with zero pages. 



This fixes an oops reported by Jason Baron.

Signed-off-by: default avatarDavid Mosberger-Tang <davidm@hpl.hp.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 2bfe9490

arch/ia64/mm/init.c

+17 −2
Original line number Diff line number Diff line
@@ -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();

}

include/asm-ia64/pgtable.h

+6 −2
Original line number Diff line number Diff line
@@ -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

#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