From cdfb82fff33cf3b1a367a427e5d89a012dc568b1 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Tue, 19 Apr 2005 13:29:22 -0700 Subject: [PATCH] [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: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/arm26/kernel/sys_arm.c | 9 ++++----- include/asm-arm26/pgtable.h | 7 +++++++ 2 files changed, 11 insertions(+), 5 deletions(-) diff --git a/arch/arm26/kernel/sys_arm.c b/arch/arm26/kernel/sys_arm.c index e7edd201579a..85457897b8a9 100644 --- a/arch/arm26/kernel/sys_arm.c +++ b/arch/arm26/kernel/sys_arm.c @@ -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(¤t->mm->mmap_sem); diff --git a/include/asm-arm26/pgtable.h b/include/asm-arm26/pgtable.h index af0b8907dc14..4a0a00da425f 100644 --- a/include/asm-arm26/pgtable.h +++ b/include/asm-arm26/pgtable.h @@ -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)