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[PATCH] freepgt: arm26 FIRST_USER_ADDRESS PAGE_SIZE

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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: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Hugh Dickins 2005-04-19 13:29:22 -07:00 committed by Linus Torvalds
parent 6119be0bba
commit cdfb82fff3
2 changed files with 11 additions and 5 deletions
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9
arch/arm26/kernel/sys_arm.c
View File

@ -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);

7
include/asm-arm26/pgtable.h
View File

@ -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)