Commit 538722ca authored by Steven J. Magnani's avatar Steven J. Magnani Committed by Michal Simek
Browse files

microblaze: fix get_user/put_user side-effects



The Microblaze implementations of get_user() and (MMU) put_user() evaluate
the address argument more than once. This causes unexpected side-effects for
invocations that include increment operators, i.e. get_user(foo, bar++).

This patch also removes the distinction between MMU and noMMU put_user().

Without the patch:
  $ echo 1234567890 > /proc/sys/kernel/core_pattern
  $ cat /proc/sys/kernel/core_pattern
  12345
Signed-off-by: default avatarSteven J. Magnani <steve@digidescorp.com>
parent 0d5961b7
......@@ -182,6 +182,39 @@ extern long __user_bad(void);
* Returns zero on success, or -EFAULT on error.
* On error, the variable @x is set to zero.
*/
#define get_user(x, ptr) \
__get_user_check((x), (ptr), sizeof(*(ptr)))
#define __get_user_check(x, ptr, size) \
({ \
unsigned long __gu_val = 0; \
const typeof(*(ptr)) __user *__gu_addr = (ptr); \
int __gu_err = 0; \
\
if (access_ok(VERIFY_READ, __gu_addr, size)) { \
switch (size) { \
case 1: \
__get_user_asm("lbu", __gu_addr, __gu_val, \
__gu_err); \
break; \
case 2: \
__get_user_asm("lhu", __gu_addr, __gu_val, \
__gu_err); \
break; \
case 4: \
__get_user_asm("lw", __gu_addr, __gu_val, \
__gu_err); \
break; \
default: \
__gu_err = __user_bad(); \
break; \
} \
} else { \
__gu_err = -EFAULT; \
} \
x = (typeof(*(ptr)))__gu_val; \
__gu_err; \
})
#define __get_user(x, ptr) \
({ \
......@@ -206,12 +239,6 @@ extern long __user_bad(void);
})
#define get_user(x, ptr) \
({ \
access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) \
? __get_user((x), (ptr)) : -EFAULT; \
})
#define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \
({ \
__asm__ __volatile__ ( \
......@@ -266,6 +293,42 @@ extern long __user_bad(void);
*
* Returns zero on success, or -EFAULT on error.
*/
#define put_user(x, ptr) \
__put_user_check((x), (ptr), sizeof(*(ptr)))
#define __put_user_check(x, ptr, size) \
({ \
typeof(*(ptr)) __pu_val; \
typeof(*(ptr)) __user *__pu_addr = (ptr); \
int __pu_err = 0; \
\
__pu_val = (x); \
if (access_ok(VERIFY_WRITE, __pu_addr, size)) { \
switch (size) { \
case 1: \
__put_user_asm("sb", __pu_addr, __pu_val, \
__pu_err); \
break; \
case 2: \
__put_user_asm("sh", __pu_addr, __pu_val, \
__pu_err); \
break; \
case 4: \
__put_user_asm("sw", __pu_addr, __pu_val, \
__pu_err); \
break; \
case 8: \
__put_user_asm_8(__pu_addr, __pu_val, __pu_err);\
break; \
default: \
__pu_err = __user_bad(); \
break; \
} \
} else { \
__pu_err = -EFAULT; \
} \
__pu_err; \
})
#define __put_user(x, ptr) \
({ \
......@@ -290,18 +353,6 @@ extern long __user_bad(void);
__gu_err; \
})
#ifndef CONFIG_MMU
#define put_user(x, ptr) __put_user((x), (ptr))
#else /* CONFIG_MMU */
#define put_user(x, ptr) \
({ \
access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) \
? __put_user((x), (ptr)) : -EFAULT; \
})
#endif /* CONFIG_MMU */
/* copy_to_from_user */
#define __copy_from_user(to, from, n) \
......
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