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Commit cdfb82ff authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds
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[PATCH] freepgt: arm26 FIRST_USER_ADDRESS PAGE_SIZE 



ARM26 define FIRST_USER_ADDRESS as PAGE_SIZE (beyond the machine vectors when
they are mapped low), and use that definition in place of locally defined
MIN_MAP_ADDR.  Previously, ARM26 permitted user mappings at 0 if the machine
vectors were mapped high; but that's inconsistent with ARM, and
FIRST_USER_ADDRESS would then have to be determined at runtime.  Let's fix it
at PAGE_SIZE throughout the architecture.

Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 6119be0b

arch/arm26/kernel/sys_arm.c

+4 −5
Original line number Diff line number Diff line
@@ -64,10 +64,10 @@ inline long do_mmap2( 
	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);



	/*

	 * If we are doing a fixed mapping, and address < PAGE_SIZE,

	 * If we are doing a fixed mapping, and address < FIRST_USER_ADDRESS,

	 * then deny it.

	 */

	if (flags & MAP_FIXED && addr < PAGE_SIZE && vectors_base() == 0)

	if (flags & MAP_FIXED && addr < FIRST_USER_ADDRESS)

		goto out;



	error = -EBADF;
@@ -121,11 +121,10 @@ sys_arm_mremap(unsigned long addr, unsigned long old_len, 
	unsigned long ret = -EINVAL;



	/*

	 * If we are doing a fixed mapping, and address < PAGE_SIZE,

	 * If we are doing a fixed mapping, and address < FIRST_USER_ADDRESS,

	 * then deny it.

	 */

	if (flags & MREMAP_FIXED && new_addr < PAGE_SIZE &&

	    vectors_base() == 0)

	if (flags & MREMAP_FIXED && new_addr < FIRST_USER_ADDRESS)

		goto out;



	down_write(&current->mm->mmap_sem);

include/asm-arm26/pgtable.h

+7 −0
Original line number Diff line number Diff line
@@ -62,6 +62,13 @@ 
#define PTRS_PER_PMD            1

#define PTRS_PER_PTE            32



/*

 * This is the lowest virtual address we can permit any user space

 * mapping to be mapped at.  This is particularly important for

 * non-high vector CPUs.

 */

#define FIRST_USER_ADDRESS	PAGE_SIZE



#define FIRST_USER_PGD_NR       1

#define USER_PTRS_PER_PGD       ((TASK_SIZE/PGD_SIZE) - FIRST_USER_PGD_NR)