From: Hugh Dickins 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 Signed-off-by: Andrew Morton --- 25-akpm/arch/arm26/kernel/sys_arm.c | 9 ++++----- 25-akpm/include/asm-arm26/pgtable.h | 7 +++++++ 2 files changed, 11 insertions(+), 5 deletions(-) diff -puN arch/arm26/kernel/sys_arm.c~freepgt2-arm26-first_user_address-page_size arch/arm26/kernel/sys_arm.c --- 25/arch/arm26/kernel/sys_arm.c~freepgt2-arm26-first_user_address-page_size 2005-04-06 18:22:08.000000000 -0700 +++ 25-akpm/arch/arm26/kernel/sys_arm.c 2005-04-06 18:22:08.000000000 -0700 @@ -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, unsig 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(¤t->mm->mmap_sem); diff -puN include/asm-arm26/pgtable.h~freepgt2-arm26-first_user_address-page_size include/asm-arm26/pgtable.h --- 25/include/asm-arm26/pgtable.h~freepgt2-arm26-first_user_address-page_size 2005-04-06 18:22:08.000000000 -0700 +++ 25-akpm/include/asm-arm26/pgtable.h 2005-04-06 18:22:08.000000000 -0700 @@ -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) _