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authorSteven J. Magnani <steve@digidescorp.com>2010-05-06 17:38:33 -0400
committerMichal Simek <monstr@monstr.eu>2010-05-13 03:21:14 -0400
commit538722ca3b762023ac65cec214901a1ebff8b575 (patch)
tree5d4ca0048a9351744fcfa6b5ca2cc25e090882f6 /arch/microblaze
parent0d5961b7f612f8f54fd6fbe1942cdfb141cddfb9 (diff)
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: Steven J. Magnani <steve@digidescorp.com>
Diffstat (limited to 'arch/microblaze')
-rw-r--r--arch/microblaze/include/asm/uaccess.h87
1 files changed, 69 insertions, 18 deletions
diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h
index 446bec29b142..26460d15b338 100644
--- a/arch/microblaze/include/asm/uaccess.h
+++ b/arch/microblaze/include/asm/uaccess.h
@@ -182,6 +182,39 @@ extern long __user_bad(void);
182 * Returns zero on success, or -EFAULT on error. 182 * Returns zero on success, or -EFAULT on error.
183 * On error, the variable @x is set to zero. 183 * On error, the variable @x is set to zero.
184 */ 184 */
185#define get_user(x, ptr) \
186 __get_user_check((x), (ptr), sizeof(*(ptr)))
187
188#define __get_user_check(x, ptr, size) \
189({ \
190 unsigned long __gu_val = 0; \
191 const typeof(*(ptr)) __user *__gu_addr = (ptr); \
192 int __gu_err = 0; \
193 \
194 if (access_ok(VERIFY_READ, __gu_addr, size)) { \
195 switch (size) { \
196 case 1: \
197 __get_user_asm("lbu", __gu_addr, __gu_val, \
198 __gu_err); \
199 break; \
200 case 2: \
201 __get_user_asm("lhu", __gu_addr, __gu_val, \
202 __gu_err); \
203 break; \
204 case 4: \
205 __get_user_asm("lw", __gu_addr, __gu_val, \
206 __gu_err); \
207 break; \
208 default: \
209 __gu_err = __user_bad(); \
210 break; \
211 } \
212 } else { \
213 __gu_err = -EFAULT; \
214 } \
215 x = (typeof(*(ptr)))__gu_val; \
216 __gu_err; \
217})
185 218
186#define __get_user(x, ptr) \ 219#define __get_user(x, ptr) \
187({ \ 220({ \
@@ -206,12 +239,6 @@ extern long __user_bad(void);
206}) 239})
207 240
208 241
209#define get_user(x, ptr) \
210({ \
211 access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) \
212 ? __get_user((x), (ptr)) : -EFAULT; \
213})
214
215#define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ 242#define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \
216({ \ 243({ \
217 __asm__ __volatile__ ( \ 244 __asm__ __volatile__ ( \
@@ -266,6 +293,42 @@ extern long __user_bad(void);
266 * 293 *
267 * Returns zero on success, or -EFAULT on error. 294 * Returns zero on success, or -EFAULT on error.
268 */ 295 */
296#define put_user(x, ptr) \
297 __put_user_check((x), (ptr), sizeof(*(ptr)))
298
299#define __put_user_check(x, ptr, size) \
300({ \
301 typeof(*(ptr)) __pu_val; \
302 typeof(*(ptr)) __user *__pu_addr = (ptr); \
303 int __pu_err = 0; \
304 \
305 __pu_val = (x); \
306 if (access_ok(VERIFY_WRITE, __pu_addr, size)) { \
307 switch (size) { \
308 case 1: \
309 __put_user_asm("sb", __pu_addr, __pu_val, \
310 __pu_err); \
311 break; \
312 case 2: \
313 __put_user_asm("sh", __pu_addr, __pu_val, \
314 __pu_err); \
315 break; \
316 case 4: \
317 __put_user_asm("sw", __pu_addr, __pu_val, \
318 __pu_err); \
319 break; \
320 case 8: \
321 __put_user_asm_8(__pu_addr, __pu_val, __pu_err);\
322 break; \
323 default: \
324 __pu_err = __user_bad(); \
325 break; \
326 } \
327 } else { \
328 __pu_err = -EFAULT; \
329 } \
330 __pu_err; \
331})
269 332
270#define __put_user(x, ptr) \ 333#define __put_user(x, ptr) \
271({ \ 334({ \
@@ -290,18 +353,6 @@ extern long __user_bad(void);
290 __gu_err; \ 353 __gu_err; \
291}) 354})
292 355
293#ifndef CONFIG_MMU
294
295#define put_user(x, ptr) __put_user((x), (ptr))
296
297#else /* CONFIG_MMU */
298
299#define put_user(x, ptr) \
300({ \
301 access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) \
302 ? __put_user((x), (ptr)) : -EFAULT; \
303})
304#endif /* CONFIG_MMU */
305 356
306/* copy_to_from_user */ 357/* copy_to_from_user */
307#define __copy_from_user(to, from, n) \ 358#define __copy_from_user(to, from, n) \