From f663b60f5215b44d147ee0c07d17ffd7e9f3f881 Mon Sep 17 00:00:00 2001 From: Michal Simek Date: Thu, 28 Mar 2013 16:42:44 +0100 Subject: microblaze: Fix uaccess_ok macro Fix access_ok macro no to permit case where user will try to access the last address space which is equal to segment address. Example: segment addr = 0xbfff ffff address = 0xbfff fff0 size = 0x10 Current wrong implementation 0xbfff ffff >= (0xbfff fff0 | 0x10 | (0xbfff fff0 + 0x10)) 0xbfff ffff >= (0xbfff fff0 | 0xc000 0000) 0xbfff ffff >= 0xf000 0000 return 0 which is access failed even the combination is valid. because get_fs().seq returns the last valid address. This patch fix this problem. Size equals to zero is valid access. Signed-off-by: Michal Simek --- arch/microblaze/include/asm/uaccess.h | 30 +++++++++++++++++++----------- 1 file changed, 19 insertions(+), 11 deletions(-) (limited to 'arch') diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h index a1ab5f0009e..efe59d88178 100644 --- a/arch/microblaze/include/asm/uaccess.h +++ b/arch/microblaze/include/asm/uaccess.h @@ -90,17 +90,25 @@ static inline int ___range_ok(unsigned long addr, unsigned long size) #else -/* - * Address is valid if: - * - "addr", "addr + size" and "size" are all below the limit - */ -#define access_ok(type, addr, size) \ - (get_fs().seg >= (((unsigned long)(addr)) | \ - (size) | ((unsigned long)(addr) + (size)))) - -/* || printk("access_ok failed for %s at 0x%08lx (size %d), seg 0x%08x\n", - type?"WRITE":"READ",addr,size,get_fs().seg)) */ - +static inline int access_ok(int type, const void __user *addr, + unsigned long size) +{ + if (!size) + goto ok; + + if ((get_fs().seg < ((unsigned long)addr)) || + (get_fs().seg < ((unsigned long)addr + size - 1))) { + pr_debug("ACCESS fail: %s at 0x%08x (size 0x%x), seg 0x%08x\n", + type ? "WRITE" : "READ ", (u32)addr, (u32)size, + (u32)get_fs().seg); + return 0; + } +ok: + pr_debug("ACCESS OK: %s at 0x%08x (size 0x%x), seg 0x%08x\n", + type ? "WRITE" : "READ ", (u32)addr, (u32)size, + (u32)get_fs().seg); + return 1; +} #endif #ifdef CONFIG_MMU -- cgit v1.2.3