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Commit f663b60f authored by Michal Simek's avatar Michal Simek
Browse files

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: default avatarMichal Simek <michal.simek@xilinx.com>
parent 6dc92c9c

arch/microblaze/include/asm/uaccess.h

+19 −11
Original line number Diff line number Diff line
@@ -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