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 <michal.simek@xilinx.com>
diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h
index a1ab5f0..efe59d8 100644
--- a/arch/microblaze/include/asm/uaccess.h
+++ b/arch/microblaze/include/asm/uaccess.h
@@ -90,17 +90,25 @@
#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))))
+static inline int access_ok(int type, const void __user *addr,
+ unsigned long size)
+{
+ if (!size)
+ goto ok;
-/* || printk("access_ok failed for %s at 0x%08lx (size %d), seg 0x%08x\n",
- type?"WRITE":"READ",addr,size,get_fs().seg)) */
-
+ 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