Skip to content

Commit

Permalink
[PATCH] freepgt: arm26 FIRST_USER_ADDRESS PAGE_SIZE
Browse files Browse the repository at this point in the history
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>
  • Loading branch information
Hugh Dickins authored and Linus Torvalds committed Apr 19, 2005
1 parent 6119be0 commit cdfb82f
Show file tree
Hide file tree
Showing 2 changed files with 11 additions and 5 deletions.
9 changes: 4 additions & 5 deletions arch/arm26/kernel/sys_arm.c
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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);
Expand Down
7 changes: 7 additions & 0 deletions include/asm-arm26/pgtable.h
Original file line number Diff line number Diff line change
Expand Up @@ -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)

Expand Down

0 comments on commit cdfb82f

Please sign in to comment.