diff options
author | Steven J. Magnani <steve@digidescorp.com> | 2010-05-06 17:38:33 -0400 |
---|---|---|
committer | Michal Simek <monstr@monstr.eu> | 2010-05-13 03:21:14 -0400 |
commit | 538722ca3b762023ac65cec214901a1ebff8b575 (patch) | |
tree | 5d4ca0048a9351744fcfa6b5ca2cc25e090882f6 /arch/microblaze/include | |
parent | 0d5961b7f612f8f54fd6fbe1942cdfb141cddfb9 (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/include')
-rw-r--r-- | arch/microblaze/include/asm/uaccess.h | 87 |
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) \ |